Red Imported Fire Ant Management Applied Research and Demonstration Report 1997-2001

RED IMPORTED FIRE ANT MANAGEMENT
APPLIED RESEARCH AND DEMONSTRATION REPORTS
1997-2001

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Control of Imported Fire Ant Colonies by Field Removal
- Bastiaan M. Drees

This handbook includes 23 reports of applied research, result and method demonstrations conducted by faculty and staff of the Texas Cooperative Extension (previously the Texas Agricultural Extension Service or TAEX). Minimal editing of submitted reports by Bastiaan M. Drees, Professor and Extension Entomologist and Coordinator of the Texas Fire Ant Research & Management Project, made these reports somewhat uniform. Not all field and laboratory trials reported herein were conducted by personnel or funded directly by the Texas Fire Ant Project. Reports were compiled to depict as a broader representation of red imported fire ant research and Extension activities within the Texas A&M University Systems's Texas Cooperative Extension.

The authors would like to thank the following companies and individuals who have supported the work of the Texas Cooperative Extension's Fire Ant Applied Research Program through direct grants, gifts and/or donations of products.

American Cyanamid Company
Aventis (Rhone-Poulenc)
The Clorox Sales Company
Dow AgroSciences LLC
FMC
Novartis Crop Protection, Inc.
The Scott's Company (Ortho)
Troy Biosciences
Valent USA Corporation
Wellmark International
Texas Army National Guard

Mention of trademark or proprietary product does not constitute an endorsement of the product by the Texas Cooperative Extension or the Texas Agricultural Experiment Station and does not imply its approval to the exclusion of other products that also may be suitable. Neither the Cooperative Extension nor the Texas Fire Ant Research and Management Plan endorses or discourages the use of any of the products mentioned in this compilation of reports.

Because of rapid changes in product development, regulatory and market conditions and ongoing scientific research, product names and availability may change. Product names and formulations used here were those from the product label itself or those suggested by the manufacturer at the time the tests were conducted.

Control of Imported Fire Ant Colonies by Field Removal
Bastiaan M. Drees, Professor and Extension Entomologist

In "The Texas Two-Step Method: Do-it-yourself Fire Ant Control for Homes and Neighborhoods" (Merchant and Drees, 2000, L-5070, Texas Agricultural Extension Service, Texas A&M University) and some popular magazines (Organic Gardening, April 2001), one non-chemical control option discussed encourages people to remove fire ant colonies by digging them up and then placing them in a bucket containing soapy water to drown the ants. This trial was conducted to determine if this method actually eliminates field colonies from the landscape as a method of imported fire ant control.

Four pairs of plots of various sizes were established, November 15, 2000 (150 by 15 ft. or 2,250 sq. ft. pair; 30 by 30 ft. or 900 sq. ft. pair; 39 by 48 ft. or 1,872 sq. ft. pair; and 75 by 75 ft. or 5,625 sq. ft. pair). Each plot contained 6 red imported fire ant mounds. In one of each pair of plots, ant colonies were removed by shoveling them into a 5 gallon plastic bucket until all visible brood and most of the worker ants had been eliminated from the field location. Colonies in the other pair of plots was slightly disturbed to determine ant activity and presence of brood (larval and pupal stages). All ant mound sites were marked for later observation. At 5, 11, 19, 35 and 51 days (Nov. 20, 26, Dec. 4, 20, 2000 and Jan. 5, 2001) after establishing this trial, marked mound sites were monitored for ant mounding activity to determine if colonies had been successfully removed from the field. On Nov. 22, 2000 due to the many active ant mounds in plots where colonies were removed, an effort was made to physically remove even more of the colonies remaining.

Data were analyzed using the Student's t test (P < 0.05) to compare mean numbers of imported fire ant mounds from "dug" versus control plots and "new" mounds appearing within treatment plots for each post-treatment evaluation date and for of these dates combined. Percent "control" was calculated for each evaluation date by dividing the number of ant active mounds from treated ("dug") plot means by active mound numbers in untreated plots, subtraction the total from 1 and multiplying by 100. Similarly, percent change in the number of "new" ant mounds detected in each plot was calculated, and finally the percent change was calculated for the "total" ant mound per plot means.

Field Removal: This trial was conducted during a period of cool temperatures, with several night temperatures approaching freezing during previous nights, and the temperature of the day this trial was established was less than 60 degrees F and overcast. Two of the plots were established in morning hours (8:30 to 9:45 a.m.), and two were established in the afternoon (2:30 to 4:00 p.m.). Colonies removed from the field were either taken into the laboratory for further studies or placed into a single pile 150 ft. from any of the plot sites. One colony removed from the field was drowned in soapy water as described below.

To remove imported fire ant colonies from the field without being stung in the process is a challenge and a concern for anyone trying to follow directions for this "control method." With temperatures below 60 degrees, the cold-blooded ants move much more slowly. To prepare to dig colonies, protective clothing, such as rubber gloves and boots, liberally dusted with baby powder (corn starch or talcum), reduces the probability of being stung by "angry" worker ants. The shovel handle and inner surface of the 5-gallon bucket were also dusted with baby powder using a large ball of cotton to apply the dust. Fire ant workers can not crawl up vertical surfaces dusted with baby powder as long as the powder remains dry and in place.

After identifying active ant mounds, they were removed by digging them from the soil and placing the ant-containing soil into the 5-gallon bucket. In the case of small to medium sized ant mounds (4-6 inches in diameter), only ½ to 3/4 of the bucket was filled with soil. In the case of large mounds (12 to 18 inches in diameter), ant-containing soil filled the bucket or required two buckets-full to remove the field colony. Because temperatures had been cool, ants and brood were found to be deep in the soil, with "pockets" of brood being found 6 to 9 inches below soil level. During warmer, sunny periods, brood and ants would be expected to be closer to the mound surface and colonies easier to remove. However, they would be moving much faster, increasing the probability of being stung. Data from the 5 day "post-treatment" evaluation indicated most sites from which ant colonies were dug still had ant colony activity. Therefore, a second attempt was made to remove ant-containing dirt from the site. The diameters and depths of holes dug to remove ants were measured on the day the trial was terminated, January 5, 2000, and averaged 17.2 inches wide by 6.4 inches deep (per plot: 13.3 inches wide by 5.2 inches deep; 17.5 by 7.6; 20.8 by 6.7; 17.2 by 6.2), with a range from 10 to 24 inches wide and 4 to 10 inches deep.

"Drowning ants": To "drown" ant colonies, 2.5 gallons of water were added to a second 5-gallon bucket and 6 fl. oz. Dawn liquid dishwashing (2 fl. oz. per gallon detergent was added and stirred. The soapy water was then added to the ant-and-soil-containing bucket. This technique eliminated sloshing or splashing of water and allowed the proper amount of soapy water to be added to whatever volume of ant-containing-soil was in the bucket. Ant activity was eliminated within a matter of minutes using this technique, as expected.

Control of Field Colonies by Digging and Removal: Five days (Nov. 20, 3:15 p.m.) from removal of ant colonies, plots were inspected (Table 1). Rain and cool nights, near freezing, had occurred during this period. However, high temperatures in the afternoon were in the low 60's. In most sites, ants and brood were seen nesting on the upper, sun-lit, edge of the hole. In only a few sites where mounds had been removed ants were not present. Presence of queen ants was not determined. Plots in sandier soil with larger colonies had more active mounds. In heavy black clay plots with smaller (>6 inch diameter) mounds, less ant activity was noted. Evidently, a single attempt at field removal of colonies on a cool day was not very successful.

Throughout the 51 day monitoring period, percent "control" of ant mounds dug out of field plots ranged between 8.6 and 43.4 percent (Table 1), although the sites from which colonies were removed did appear to have far fewer ants than were associated with untreated ant colony sites. No significant differences were found between treatments ("dug" versus untreated) for any date except on the 5 day post-treatment date (3.50 + 1.73 "dug" versus 5.50 + 0.58 "untreated check"; t = -2/1909; P = 0.0355; d. f. = 6). For the analysis of data for all post-treatment sampling dates, were was a statistically significant 27.9 percent reduction of ant mound numbers per plot between "dug" (3.75 + 1.80) versus "untreated check" (5.20 + 0.6959) (t = -3/3667; P = 0.0009; d. f. = 38). Although not significantly different, there were generally, more "new" ant mounds observed in plots from which colonies were removed throughout this period (ranging from 13.3 to 46.5 percent more "new" ant colonies), suggesting that ants remaining after their colonies were disturbed by digging most likely moved to a new, nearby site to construct a new, "satellite" ant mound. As a result, the actual "control" of imported fire ant colonies per unit area ("total" of treated or dug plus "new" ant colonies) ranged from 14.1 percent reduction to a 12.8 percent increase in colony numbers over the monitoring period.

These results do not support a management suggestion for physical removal of imported fire ant colonies from the field by shoveling them into a bucket as a non-chemical control method, whether one drowns the ants after collection or not. Different results could be obtained if this trial were to be repeated at a different time of the year, under different environmental conditions or in sites with different soil types or ant forms (the ants in these sites were assumed to be the polygyne or multiple queen form of the red imported fire ant).

Despite care taken to avoid being stung by the ants, this researcher experienced some stings in carrying out this trial. Therefore, this method of "control" should be discouraged by anyone with a sensitivity to insect stings and venom.

Table 1. Elimination of red imported fire ant from field plots by shoveling ant mounds into a 5-gallon plastic bucket
Brazos Co., Texas, Nov. 15, 2000.

Fire ant mounds per field plot/6 ant mounds (replicated 4 times)
Days following colony removal

Laboratory Assay of Effect of Instant Grits and Malt-O-Meal for Imported Fire Ant Control
Bastiaan M. Drees, Professor and Extension Entomologist

Use of instant grits or similar products has been a home remedy for attempted red imported fire ant control throughout the Southeastern United States. The practice has become fairly common and those using the technique have reported good results so frequently that the practice has become recommended by certain organic gardeners and practitioners (H. Garret. 1993. Texas Organic Gardening Book. Gulf Publishing Company. Houston, Texas. (p. 140) 245 pp.). This laboratory study was undertaken to develop some scientific data regarding the effects of instant grits and Malt-O-Meal in fire ant colonies.

Filtering capacity of ants. "Solids are inevitably consumed by worker ants during grooming as well as foraging, but are excluded from the ants' liquid diet before food is ingested. The unique filtering capability is facilitated by two structures that have evolved to become integral parts of the ants' alimentary tract. The buccal tube (BT) is a narrow passageway, lined with setae (hairs), leading from the oral cavity to the pharynx. Particles that are too large to pass through the BT are retained within a ventral infolding of the oral cavity, the infrabuccal pocket (IBP). If particles of a specific size are fed to an ant and the number of particles recovered from its IBP is divided by the total number of particles recovered from both the IBP and the crop, the resulting ratio provides an estimate of the ant's filtering effectiveness at that particle size. Matrix-bound, micro-encapsulated, or microbial control agents whose delayed mode of action requires ingestion would be unlikely candidates as potential formicides for ant species who could, due to particle size, exclude them from their diet." The red imported fire ant workers are extremely effective at excluding 82 percent of 0.2µm diameter microspheres from a sugar water solution. At diameters of 0.5 and 0.75µm, workers filtered 98 and >99 percent of microshpheres, respectively. No microspheres with a diameter of 1.0 or 1.8µm were recovered from the crop of any worker (From: John M. Petti. 1997. "A comparison of food filtering efficiency in workers of the red imported fire ant, Pharoah ant, and Florida carpenter ant", pp. 97-98, in Proceedings of the 1997 Imported Fire Ant Research Conference", Gainesville, FL).

This trial was initiated on November 15, 2000, when twelve red imported fire ant colonies were dug from field locations into 5-gallon plastic buckets. The inner surfaces of the buckets and shovel handle had been liberally dusted with baby powder to prevent ants from climbing up the vertical surfaces to escape. Colonies were placed in the laboratory and maintained at room temperature throughout the duration of this trial. After colonies in buckets had been given a day to establish in he bucket, four colonies each were given either instant grits, Malt-O-Meal or nothing (untreated control). Colonies were monitored 1, 2, 5, 7, 11, 19 days (Nov. 16, 17, 20, 22, 26, Dec. 4) following treatment to determine if colonies were active and surviving.

By using this laboratory assay method, results are replicated (4 times), and were conducted at room temperature to overcome cooler outdoor conditions at that time of year which would have reduced ant foraging on the "bait" treatment particles. In addition, ant colonies could not migrate or move away from the treatment site, which is a problem in field trials when determining if a colony perished or merely re-located. Field studies, however, during warmer climactic conditions should be conducted to confirm these laboratory observations.

Examination of colonies at the five-day inspection confirmed that the two replicates of colonies dug in an area of heavy black clay soil were all very weak and small. They were each provided a tube of water. Each colony was given two seafood-flavored seafood pellets (Tender Vitals®). Ants from colonies dug in sandier soil continued to actively move soil, building up "mounds" housed in buckets.

On Nov. 26, ants in one bucket treated with grits, collected from black clay soil, appeared to have declining activity. All colonies dug from that substrate (2 replicates) showed less activity than ants collected from sandier soil. At the end of the trial, ant colonies in buckets were returned to the field and soil was examined for presence of ants and developing stages (larvae and pupae). All twelve colonies were found to be alive and were producing at least some brood. However, food particles were found throughout the soil profile, indicating that, indeed, the foraging worker ants retrieved the particles and brought them into the nest. Because no colony was eliminated by either treatment, no statistical analysis was conducted on these data.

Results of this no-choice, laboratory study do not support use of instant grits or Malt-O-Meal as an effective treatment for eliminating colonies of the red imported fire ant.

Red imported fire ant colony survival after receiving 1 cup Malt-O-Meal, instant grits or no treatment (1 = live colony).

Comparison of Organic Products Against Individual Red Imported Fire Ant Mounds
John Brannen, Global Organic Resources Cooperator
Nathan L. Riggs, Extension Agent - IPM Bexar County

Summary: Four products produced by the Global Organic Resources Company were compared with Ortho® Ant Stop Orthene® Fire Ant Killer and Gardenville's Orange Oil Fire Ant Killer against individual Red Imported Fire Ant mounds in a non-replicated test. All gave excellent control of mounds within 48 hrs after treatment. At one and three weeks after treatment, all treatments had reduced the number of active treated mounds by 100 percent. The costs per mound ranged from ~$0.19 for Orthene® dust to ~$2.40 for Gardenville's Fire Ant product.

Red imported fire ants, Solenopsis invicta Buren, cause an estimated $16 million per year in various costs in Bexar County. There are many methods and products available to the average homeowner for managing fire ant problems in the landscape. However, there is a growing demand from homeowners for more "organic" strategies to allow them to battle fire ants in their lawns and gardens. This demonstration was designed to compare some new organic-type fire ant products against those available at the present time (Orthene® dust, Gardenville Orange Oil Fire Ant Killer, Organic Solutions Multipurpose Fire Ant Killer).

Groups of 10 red imported fire ant mounds were flagged and assigned to one of 7 treatments (Table 1) including an untreated control group. The test site was located in west Bexar County at the Brannen homestead. Mounds were treated on July 19 in the late afternoon with a temperature of 90ºF and dry conditions. Mounds were located in black soil with a caliche base. All mounds were active prior to treatment. Mounds treated with Orthene® dust received 2 teaspoons of material without water, the Gardenville group received 6 oz of product per gallon of water, the 4 Organic Resources products were prepared at 4 TB of product per gallon of water, and the untreated mounds received 1 gallon of fresh water each.

Mound evaluations were made at 24 and 48 hours, and 1 and 4 weeks after treatment. In addition to mound evaluations, mounds were inspected for evidence of new, "satellite" mound formation within 12-18" of the original treated mound. Gardenville and untreated mounds received one gallon of water or solution from a watering can. Mounds treated with Organic Resources products were treated with 1 gallon of solution pumped from either a gasoline or battery powered sprayer attached to a tank on a small trailer. Treatments were not replicated.

Results for all evaluations are given in Table 2. All of the materials tested gave 100 percent control of fire ant mounds within 1 week of treatment. "Satellite" mounds were seen forming at 24 and 48 hours post treatment (PT) in all groups except untreated and Orthene® dust. One "satellite" mound in the Gardenville group remained active throughout the duration of the demonstration. The remaining "satellite" mounds appeared to be inactive after the 1 week evaluation. During treatment of the Diatect Results group, the application pump malfunctioned consequently reducing the amount of material applied to one large fire ant mound.

These results present a relatively inexpensive and effective means for the average homeowner to manage fire ant problems in their lawns and gardens. These results provide efficacy data for additional weapons in the vast arsenal available to homeowners to battle fire ants.

We would like to thank the Brannen family for providing the products, test site, and sponsorship for this demonstration, and Dr. Charles Barr, Extension Program Specialist for his assistance in beginning this experiment.

Table 2. Mound evaluation results at 24 and 48 hours and 1 and 4 weeks post treatment - number of active mounds out of 10.

* Conditions have been very hot and dry in the 4 weeks since treatment. At the time of the final evaluation, the air temperature was ~98º F. Some ant colonies had moved deeper into the ground and did not respond to mild mound disturbance.

Use of Broadcast Bait Treatments to Reduce Infestations of
Red Imported Fire Ants at the Kendall County 4H Horse Arena
21 October 1999
Nathan Riggs, EA-IPM (Bexar County) and Bob Bailey, CEA-Ag (Kendall County)
Boerne, Texas
Kendall County, Precinct 2

Summary: Amdro® (hydramethylnon) and Spectracide® (pyriproxyfen) fire ant baits broadcasted at the recommended rates of 1 pound per acre and 1 pound per 0.1 acre respectively reduced the number of active mounds in a small demonstration, by 80 and 100 percent, ten weeks after treatment. Broadcasting baits saved an estimated $1.16 and $0.19 per mound when compared to hypothetical individual mound treatments of the same area.

The red imported fire ant, Solenopsis invicta Buren, is an aggressive protector of its mounds, stinging any and all sources of disturbance near the nest. At the Kendall County 4-H Horse Arena, fire ant mounds are numerous along the arena edges, in the grassy areas outside of the arena, around the concession stands and the grandstands. With such high concentrations of fire ant mounds in these well-traveled areas, it is difficult for spectators to stand around and enjoy horse shows, rodeos, and other similar events.

To demonstrate how an inexpensive broadcast application of a fire ant bait insecticide can reduce the number of fire ant mounds in an area without expending more valuable time and money treating individual fire ant mounds.

The Kendall County 4-H Horse Arena is located approximately 2 miles east of Boerne on Texas Highway 46. The area is laid out with a central rectangular dirt arena bordered by a twenty foot wide grassy area on the south, a 45 ft wide grassy area on the west including the concession stand, grandstands on the north, and approximately 1.4 acres of grass on the east. Grasses around the arena are predominantly common Bermuda with a sparse representation of weeds and other native grasses. These areas are not irrigated and receive rainfall as their only water source. Fire ant mound concentrations were not high enough to do a statistically analyzable replicated test, but there were more than enough ant mounds to perform a method demonstration.

Amdro® Fire Ant Bait (hydramethylnon, American Cyanamid Co.) and Spectracide® Fire Ant Bait (pyriproxyfen, United Industries Corp.) were selected as the treatment products for this method demonstration. The area (8,400 ft2) along the south side of the arena was treated with approximately 3 ounces of Amdro® fire ant bait using a EZ Handspreader by Republic. Amdro was applied at the recommended rate of 1 pound per acre. A 4,400 ft2 area adjacent to the concession stand was chosen as the treatment area for the Spectracide® Fire Ant Bait. The recommended rate of 1 pound of bait was applied to the 4,400 ft2 area using a Scotts® Easy™ Hand-Held spreader. The 1.4 acre area east of the arena was left untreated for comparison. Evaluations of mound activity were made at 1 and 2 month intervals after treatment. Ten mounds were marked with red flags in each group. These 10 mounds were evaluated each time.

Areas along the south side of the horse arena and around the concession stand were treated in the late morning on April 27, l998. Air temperature at the time of treatment was 85 F. Ten mounds within each of the treated areas and the untreated area were evaluated for activity. Table 1 outlines the results of these evaluations. Biological surveys were not conducted prior to, or after treatment.

As formulated, these baits require a broadcast rate of 1 pound per acre and 1 pound per 4,400 ft2 respectively. Table 2 outlines the costs of product and treatment for this test as well as cost estimates had the mounds been individually treated with these same products. The cost of a hand-held spreader averages $5.00 to $10.00 per unit at the retail level, adding a one-time cost to the treatment program. Including labor at $6.00 per hour would have added an additional $1.50 to the Amdro® broadcast treatment for 15 minutes of labor and $0.50 to the Spectracide® broadcast treatment for 5 minutes of labor. Because no mounds were actually treated individually, no cost estimates for individual mound treatment labor were made. However, because treating fire ant mounds individually requires time to search for the mounds, it can be assumed that this method would require a higher labor cost.

When considering options for treating fire ant problems, one must consider the following factors: 1) amount of time available to perform the application; 2) funds available to purchase fire ant control products; 3) the area to be treated; and, 4) presence of desirable ant species.

Today's modern society has become very time-expensive for the average homeowner. There is not a vast quantity of time available to treat areas with fire ant problems. This small test has shown that choosing a broadcast method over an individual mound treatment method for heavy fire ant infestations can possibly save valuable time.

Broadcast bait treatments for fire ants can also save money. Amdro® and Spectracide® treatments in this small test saved $1.16 and $0.19 per mound, respectively, when broadcasted versus individual mound treatment estimates. The most important factor that ties costs and method together is the size of the area to be treated. Large areas can be more effectively covered with a broadcast of fire ant bait rather than finding all of the fire ant mounds in the area. On the other hand, smaller areas with few fire ant mounds may be better served with individual mound applications because of convenience.

In conclusion, both of the baits selected performed well and reduced the numbers of active mounds in treated areas. More importantly, broadcasting fire ant baits is a cost effective and time efficient strategy to control fire ants in large, heavily infested areas.

The author wishes to thank CEA-AG Bob Bailey of Kendall County for his cooperation in this joint county effort. Thank you also to Bret Royal of American Cyanamid for providing Amdro® fire ant bait to use in this study.

Table 1. Results of broadcast fire ant bait applications around the Kendall County 4H Horse Arena, Boerne, Texas 1999.

*Number of active mounds out of 10 evaluated

Back to Results

Table 2. Comparison of estimated costs of treating fire ant mounds individually or with a broadcast bait application-
Kendall County 4H Horse Arena, Boerne, Texas 1999.

*Per mound cost for the broadcast method is calculated by dividing the cost for the total product amount used by 10 mounds.

Final Report on Testing of TB131-1, a Beauveria bassiana Product
Manufactured by Troy Biosciences for the Control
of Individual Colonies of Red Imported Fire Ants
Charles L. Barr, Extension Program Specialist - Fire Ant Project
Rody L. Best, Extension Assistant - Fire Ant Project
Lisa Lennon - Fire Ant IPM Agent, Travis/Williamson Counties
Dale Mott - EA-IPM, Williamson/Milam Counties
Scott Russell, Fire Ant IPM Agent, Dallas/Tarrant Counties

In 1998, Troy Biosciences contracted with the Texas Agricultural Extension Service's Fire Ant Applied Research Laboratory to conduct a series of tests on their TB131-1 product, a formulation of spores from the fungus Beauveria bassiana, for the control of red imported fire ant (Solenopsis invicta Buren) colonies. Five trials were conducted to test the product's effectiveness at five different sites, at different times of the year and in different soil types. Due to persistent, widespread drought conditions from the spring of 1999 through the following fall, finding suitable test sites was difficult. Since it was felt that the fungus would perform best in warm, moist conditions, three of the four tests were completed in the spring of 2000. Table 1 summarizes the test dates, locations, site characteristics and participants.

The standard "railroad track" design described below was used for all the tests. This method provides a means of tracking not only the status of treated mounds, but also "new" mound-building activity within a defined area. In this way, the appearance of new mounds can be detected and inferences made as to whether these result from colony relocation, "shattering" (splitting into more than one colony) after treatment or from re-invasion by colonies from outside the test area.

The first step in establishing field trials using the "railroad track" design involves marking off a strip of land 30 to 40 feet wide (depending on mound density) and of indeterminate length. Starting at one end, every active fire ant mound found progressing along the strip is marked with a wire surveyor's flag until 10 are marked. Flag color is then switched for the next set of 10 and so on, alternating flag colors. Then, a third color flag is placed along the edge of the strip halfway between the last mound of one plot and the first mound of the next plot. Each set of 10 mounds and the encompassing area is considered a plot and each plot is numbered sequentially.

Plot lengths are then measured, recorded and plot numbers are arrayed from longest to shortest to give a range of plot mound density (length being inverse to density). The lengths are then divided into four equal groups so that there is a set or block of low-density plots, two medium density sets, and a high-density set. These sets represent replications. Next, treatments are randomly assigned within replications. The total length (sum of four replications) for each treatment is then calculated. If needed, treatments are then swapped within replications to try to equalize the treatment totals. In this way, all treatment plot sets have the same number of active mounds prior to treatment, within roughly the same total area. This eliminates pre-treatment differences between treatment plots and helps to equalize the chances of a colony re-locating within a plot or colonies re-invading from outside the plot following treatment.

Though the test protocols remained substantially the same, some modifications were made by the manufacturer to help increase product effectiveness. Comparison products or "standard treratments" varied by test. Exact treatments used in each test are listed in individual test result tables. Nevertheless, treatments included the following:

1) untreated control
2) TB131-1, Beauveria bassiana, ½ oz. per mound (¼ oz. per mound in Test #1)
3) TB131-1, Beauveria bassiana, ½ oz. per mound applied at test initiation and again in two weeks to still-active mounds (or ½ oz. per mound in Test #1)
4) Standard treatment (see individual test results for specific product used)

TB131-1 was applied by first punching a hole at least ½-inch in diameter in the top of a mound in the area of highest brood concentration. The product was then simply poured down the hole where it was quickly absorbed onto the soil.

Ant activity was evaluated using the minimal disturbance technique. Criteria used to consider a mound as "active" varied with weather, time of day, test site, activity of untreated mounds and the best judgement of the evaluator. Generally, a mound was considered active if 10 to 20 ants rose to the surface in a defensive manner within 15 seconds of disturbance. Evaluations were made at 7, 14 and 28-30 days post-treatment, weather permitting. Plots were surveyed at least once during the test and at the end of the test for "new" mound formation. The "total" number of mounds reported in tables are the number of active treated mounds plus "new" mounds.

All data were analyzed using PC SAS analysis of variance procedures with means separated using Tukey's studentized range test, P < 0.05.

Note: an identical test was conducted in Robertson County, November - December 1998. Due probably to the cool, wet conditions, virtually all the untreated mounds were naturally abandoned within two weeks of test initiation. Given this very unusual occurrence, the Robertson County test results are not reported here and another test was conducted later to complete the five tests needed.

Test#1 - Taylor, Williamson County, Texas. Since this was the first test in the series, two rates of TB131-1 (Beauveria bassiana), ½ and ¼ fluid ounce per mound were used. This test was conducted rather late in the season. Though the ants were building mounds quite actively, they did not appear to be foraging well. Consequently, Orthene® Fire Ant Killer (75% acephate applied at 2 teaspoons per mound) was used as the standard treatment. Weather during the test period was cool and wet, preventing the evaluation of the test more than twice. During treatment and evaluations, active mounds were built-up with brood visible near the surface. Ants were active when disturbed. Results do not show any significant (P < 0.05) differences between the number of active treated mounds in fungus-treated and untreated plots. Orthene-treated plots had significantly fewer treated mounds throughout the test, though they had numerically more "new" mounds appear after treatment. Consequently, there were no significant differences in the total number of active mounds between any of the treatments at either seven days or one month post-treatment.

Table 2. Mean number of active mounds of 10 treated or as indicated, 4 replications; Taylor, Texas

Means in the same column followed by different letters are significantly different (P < 0.05) using
PC SAS analysis of variance procedure with means separated using Tukey's studentized range test.
* Minimum significant difference

Test #2 - Navasota Airport, Grimes County, Texas. The protocol for this second trial was modified from that of the first in two ways. First, rather than two rates of TB131-1, the ½ oz. rate was used for both treatments. Both were treated at test initiation, then, in one treatment, all mounds that were still active after two-weeks were re-treated with ½ oz. of material. The second change was the use of Organic Resources (0.01% pyrethrin, 83.3% diatomaceous earth, 0.1% piperonyl butoxide applied at 4 tablespoons per gallon of water per mound) as a standard because of its "organic" nature and potential as a market competitor to TB131-1. Organic Resources is a very fast acting mound drench.

Results indicate that Organic Resources reached 100 percent control of treated mounds within three days and stayed at that level of control throughout the test. By the end of the test, TB131-1, both as a single and double application resulted in significantly (P < 0.05) fewer active, treated mounds than the untreated control. There was no indication that any of the products resulted in colony movement or shattering. At one month, the total active mounds (treatment plus new) for the TB131-1 ½ oz. x 1 was significantly less than in untreated plots.

The test was conducted during the hottest time of the year. At treatment, however, mounds were small, but freshly built-up with brood near the surface. The test site received rain a few days before test initiation, but was then subject to very high temperatures and no rain for the duration of the test, resulting in drought conditions by that time.

Table 3. Mean number of active mounds of 10 treated or as indicated, 4 replications; Navasota Airport, Grimes County, Texas

Test #3 - DFW International Airport, Texas. The trial was conducted in mid-spring with adequate moisture and moderate temperatures. TB131-1 was applied in the same manner as Test #2 with initial application and follow-up application on active mounds in one treatment. Amdro® (0.73% hydramethylnon bait applied at 5 tablespoons per mound) was used at the request of Troy BioSciences personnel as the standard comparison product for this and subsequent tests. Conditions were such that ants could forage well enough to pick up the bait.

Results indicate that only Amdro® resulted in significantly (P < 0.05) fewer active mounds versus the untreated control at two weeks and one month post-treatment. There was a substantial amount of natural mound abandonment and formation of "new" mounds in all treatments during this same period, probably the result of heavy rains.

This test was conducted with the assistance of Dr. Michael Merchant - Extension Specialist, District 4 (Dallas).

Table 4. Mean number of active mounds of 10 treated or as indicated, 4 replications; DFW International Airport, Texas

Test #4 - Coulter Field, Brazos County, Texas. This test site was chosen for its high mound density, approximately 600 mounds per acre, and sandy, claypan soil type. Weather during the test was moderate with several rains, so soil moisture was adequate throughout. Fire ant mounds were small to medium in size, but well-formed with freshly worked soil. Ants were very active with brood near the surface at the time of treatment.

Results show significantly (P < 0.05) fewer active treated mounds in Amdro®-treated plots at each evaluation date and significantly (P < 0.05) fewer total mounds (treated + new) at four weeks. There were no significant difference between TB131-1-treated plots and untreated controls, though there was some numerical reduction in the number of treated mounds at two and four weeks. There was some natural abandonment of mounds and a fairly high number of "new" mounds formed within the plots. This is probably again due to several heavy rains. New mound formation was numerically less in Amdro-treated plots than in the others at one-month post-treatment. This phenomenon was observed in the abandoned test conducted in Robertson County, where there were no new mounds found in Amdro-treated plots and a substantial number found in others.

Table 5. Mean number of active mounds of 10 treated or as indicated, 4 replications; Coulter Field, Brazos County, Texas

Test #5 - Burleson County, Texas. The pecan orchard land used for this final trial was chosen for its silty, bottomland soil type which represents some of the best cropland in the state. Weather during the test was hot and humid. Soil moisture was adequate with the site experiencing at least one moderate rain over the course of the test. Fire ant mounds were generally very small, but freshly built and with brood near the surface of most.

Results show that only Amdro® significantly (P < 0.05) reduced active mound numbers versus untreated controls at any point during the test. Because of the heat, even untreated mound numbers dropped almost 50 percent, but there were virtually no differences between TB131-1-treated and untreated mound numbers. "New" mound formation was very slight during the test because of high temperatures.

This test was conducted with the assistance of Jennifer Begnaud, Student Worker, Fire Ant Project.

Table 6. Mean number of active mounds of 10 treated or as indicated, 4 replications; Burleson County, Texas

These five trials represented a cross-section of weather and soil conditions across the state of Texas. One was performed in December, another during the hottest, driest time of year, two in nearly ideal "fire ant conditions" in the spring, and one in the late spring/early summer with adequate moisture. Soil types included heavy black calcareous clay, sand and loam over claypan and deep bottomland soil. Fire ant colonies all appeared to be of the small, but high-density polygyne type most common in the state.

The test design, informally known as the "railroad track" method after its linear string of plots, has been used for years by the Texas Agricultural Extension Service's Fire Ant Applied Research Laboratory to test a variety of individual mound treatment products. The method not only tracks the condition of treated mounds, but also helps detect colony movement, shattering and re-invasion from outside the plots in a manner that equalizes these parameters between treatments.

Results appeared to be similar among the tests, but a final statistical analysis was performed on the "bottom line" evaluation, that conducted at one month post-treatment. The first test (Taylor) had two different rates of TB131-1 product and a unique standard product, so it could not reasonably be included. Standard products also varied between the remaining tests so those treatments were eliminated, as well. Therefore, the table below includes results from the last four tests, so that each treatment represents a total of 160 treated fire ant mounds.

Table 7. Summary of TB131-1 treatment results. Mean number of active mounds, 4 tests, 4 replications per test, 10 active mounds treated per replication.

As shown, neither TB131-1 treatment reduced active mound numbers significantly (P < 0.05) versus an untreated control one month after initial treatment. Numerical differences were not substantial, either. Overall, TB131-1 gave about 50 percent control of treated mounds, but there was substantial natural mound abandonment. Field observations suggest a decline in vigor of some treated colonies, though some brood was still observable in most active colonies.

The most successful test in terms of TB131-1s performance was the one conducted at the Navasota airport during August 1999. Despite high temperatures and very dry conditions, the product gave roughly 50 percent control of treated mounds with the untreated plots maintaining over 80 percent activity.

Control by standard products ranged from a high of 100 percent by Organic Solutions in the Navasota test to a low of about 75 percent by Amdro® (hydramethylnon) in the Burleson County test. Standard treatments covered the range of product activity with Organic Solutions (pyrethrins, piperonyl butoxide and diatomaceous earth) being one of the fastest-acting and Orthene® (acephate) being one of the relatively slower of the available contact insecticide-type products. Both typically give better than 90% control when properly applied. Amdro, applied as an individual mound treatment, is the fastest acting of the bait products and usually takes a week or so to work.

In summary, we feel that this series of five trials gave TB131-1 a very thorough testing across a wide array of weather, seasonal and edaphic conditions. Despite the product's ease of use and "organic" nature that would appeal to many environmentally-conscious consumers, a control rate of only 50 percent over a month is somewhat disappointing.

Evaluation of Deltamethrin Dust for the Control of Imported Fire Ants
Lisa Lennon Extension, Integrated Pest Management– Fire Ant Project
Texas Agricultural Extension Service, Travis & Williamson Counties

Bastiaan ‘Bart' Drees, Ph.D. Coordinator, Texas Fire Ant Project
Texas Agricultural Extension Service Texas A&M University, College Station, Texas

The red imported fire ant, Solenopsis invicta Buren, is a major economic pest in Texas. This ant affects recreational activities and those who work outdoors. This trial evaluated two dust formulations used as individual mound treatment. The trial took place at Austin Tree Farm, a wholesale grower of ornamental trees, located on Colorado River bottom land. The soil type is fertile loam. The trial began on June 21, 2000 when temperatures were hot and the area was in a drought. This trial demonstrates the efficacy of dust formulations in the summer when ant activity is minimal.

According to a study conducted by the Texas A&M Agricultural Economics Department, people in the Austin area experienced significant expenditures due to fire ants of $45 million. Homeowners in the Austin area experienced the highest costs among the sectors examined, with an average of $145.39 per household (Lard, et al 2000, "The economic impact of red imported fire ant on the homescape," Dept. Agric. Econ., Texas A&M University). This figure includes costs of treatments, repairs to electrical equipment, first aid, and other services.

This trial was established to evaluate a new dust formulation and compare it to a known effective dust formula for control of fire ants. The trial was designed to observe the effectiveness of the material in summer conditions over a 30 day period.

This trial was established at Austin Tree Farm. The perimeter area of the entire farm was used, so that fire ant mounds could be flagged and monitored without much disruption of farm activity in the planting areas. The site was completely sunny and the fire ant mounds that were used bordered field areas. The farm is located approximately 25 yards from the Colorado River.

The products used were Orthene® (50% acephate) and Bengal Ultra Dust® (0.05% deltamethrin). Orthene usually provides control within 72 hours. Both dust formulations were applied at the recommended rate of application.

At 2, 7, 14, and 30 days after treatment, mounds were disturbed and evaluated for ant presence and activity, if any. Evaluation consisted of presence of live and active ants. Each mound was checked for 1) presence or absence of ant activity, 2) mound dispersal.

The results from this limited study indicate that the Bengal UltraDust® did not perform as well as Orthene® in hot, dry weather when ant activity is limited (Tables 1 & 2). Although the Orthene® performed as expected, there are limitations with all fire ant control pesticides. This study should be repeated in more conducive weather conditions to make another evaluation of the deltamethrin dust formulation.

Table 1. Red imported fire ant mounds before and following treatment with ant mound treatments Austin Tree Farm, Travis Co. TX, treated June 21, 2000.

*Use rate: Sprinkle 1 tablespoon dry powder over each mound. Do not disturb the mounds while treating.
** Use rate: Evenly sprinkle 1 teaspoon (approx. ½/ oz) over the top of each mound. Do not disturb the mound. Perimeter treatment: Apply uniformly and uniformly to the foundation and crawl spaces where pests are active and may find entrance.

Table 2. Mean number of active mounds of five treated, Austin Tree Farm, Travis Co. TX, treated June 21, 2000.

Product: Ortho® Orthene® Fire Ant Killer
Manufacturer: Solaris®, The Solaris Group of Monsanto Company, P.O. Box 5008 San Ramon, CA 94583-0808 800/225-2883 www.ortho.com Ingredient: acephate 50% (Organophosphate) CAUTION
Use rate: Sprinkle 1 tablespoon dry powder over each mound. Do not disturb the mounds while treating.
Use site(s): Home lawns, around ornamental plants (including flowers, trees & shrubs). Do not apply directly to water.
Protective clothing: Avoid contact with skin, eyes and clothing. Avoid breathing dust. Wear chemical resistant gloves, long pants, and long-sleeved shirt. Wash te gloves with soap and water before removing.
Remarks: No watering, treats 113 mounds.
Cost: 1 lb. Fire Ant Orthene: $11.43

Product: Bengal® UltraDust® Fire Ant Killer Kills the Queen Fast, Effective Kill of Fire Ants Ready To Use No Watering-In Odorless Manufacturer: Bengal Chemical Company 13739 Airline Highway, Baton Rouge, LA 70817 225/753-1313 www.bengal.com
Ingredient: deltamethrin: [(s)-alpha-cyano-3-phenoxybenzyl-(1R,3R)-3-(2-2dibromovinyl)-2,2-dimethylcyclopropanecarboxylate] 0.05% (Pyrethroid) CAUTION
Use rate: Evenly sprinkle 1 teaspoon (approx. ½/ oz) over the top of each mound. Do not disturb the mound. Perimeter treatment: Apply uniformly and uniformly to the foundation and crawl spaces where pests are active and may find entrance.
Use site(s): Also for use around roses, flowers and ornamentals. Do not apply directly to water. Protective clothing: Avoid contact with skin. Remarks:
Cost: 1 lb. ltraDust Fire Ant Kill Bengal: $4.96

Evaluation of Fire Ant Insecticide Bait Products as Single Mound Treatments
Paul R. Nester, Ph.D.
Extension Agent- IPM - Fire Ant Project
Texas Agricultural Extension Service
Harris County

Summary: The red imported fire ant, Solenopsis invicta Buren, (herein referred to as the fire ant) has become an important economic threat in urban Texas. The fire ant affects recreational activities as well as agricultural operations. This trial evaluated two new fire ant bait products and one established fire ant bait product as single mound treatments on large fire ant mounds on newly cleared residential property. All products reduced fire ant activity after two weeks. The established bait product was slightly faster acting after one week. This trial was applied May 23, 2000 when temperatures were moderate, moisture was good and fire ant activity was good. This trial demonstrates that the newer baits can be used as single mound treatments.

The fire ant, Solenopsis invicta Buren, has become an important economic threat in urban Texas. According to a 1998 study conducted by the Department of Agricultural Economics, TX A&M University, of fire ant related costs in Dallas, Fort Worth, Austin, San Antonio, and Houston, fire ants have serious economic effects for these metro areas of Texas. Households experienced the largest costs among sectors examined with a average of $151 per households spent annually which included repairs to property and equipment, first-aid, pesticides, baits, and professional services. A full damage assessment for Texas must include additional sectors, and the estimated costs of $581 million per year for the selected sectors underscore the impact of this pest. Treatment costs accounted for over 50 percent of this total cost. In Houston the average medical treatment costs per household of $25.46. The duration of injury for children and adults was 6.6 days and 5.6 days, respectively. The fire ant limits outdoor activities and homeowners and producers incur added costs in managing the fire ant.

This trial was established to evaluate two new fire ant bait products and one established fire ant bait product as single mound treatments on large fire ant mounds on newly cleared residential property. The trial was designed to observe the effectiveness of the materials in reducing fire ant activity over a four week period.

This trial was established on newly cleared residential property near The Woodlands, TX in south Montgomery County. The site was cleared in 1996 of all underbrush and small trees, leaving only trees 12 inches or greater in diameter. The plot area was lightly wooded and located 700 feet north of a creek bed. A preliminary count showed 75 fire ant mounds of 12 inches or greater per acre. Forty-eight mounds were identified as being 12 inches or greater in diameter. The mounds were grouped into 4 equal groups of 12 mounds with similar diameters.

Fire ant bait materials evaluated were: Amdro® , Clinch® and, Eliminator®. Amdro® contains 0.73% by weight hydramethylnon; Clinch® contains 0.011% by weight abamectin; and, Eliminator® contains 0.015% by weight spinosad. Amdro® usually provides control within 2 to 7 days of application when used as a single mound treatment. The trial was set to run 4 weeks and Amdro®, Clinch® and, Eliminator® were applied at the rate of 2.5 oz of product per mound area (includes mound and 3 foot radius around the mound) as directed by label.

At 7 and 15 days after treatment (DAT), 6 mounds were disturbed and evaluated for fire ant presence and activity. Each mound was checked for presence or absence of fire ant activity and level of fire ant activity (1 = < 10 fire ants or freshly worked soil; 2 = some fire ants, not aggressive; and, 3 = many aggressive fire ants). At 30 DAT all treated mounds were observed for return of activity.

The results (Tables 1 and 2) show the effectiveness of the materials during the evaluation period. All products appeared to control the fire ant 15 DAT (Table 1) but only Amdro® treated mounds showed no fire ant activity 7 DAT. Eliminator® greatly reduce fire ant activity after 7 days while some Clinch® treated mounds still had active brood after the 7 DAT evaluation period. No activity was observed in any of the treated mounds 30 DAT (Table 2).

The results from this limited study indicate that the baits tested can provide relatively fast colony elimination when applied as individual mound treatments, giving an acceptable reduction in fire ant mound activity within 2 weeks after application. Previous studies (Barr et. al.) have shown slower suppression occurs after these products are broadcast-applied. A larger, replicated study is necessary to confirm the results of this demonstration trial.

The author would like to thank Novartis Crop Protection, American Cyanamid Company, and Dow Agrosciences for the opportunity to evaluate their products.

Table 1. Results of reduction in mound activity of fire ants after treatment of different fire ant bait products. Montgomery Co., TX, 2000.

Table 2. Results of reduction in mound activity of fire ants after treatment of different fire ant bait products. Montgomery Co., TX, 2000.

Evaluation of Fire Ant Insecticide Products as
Single Mound Treatments Along Hardscape Areas
Paul R. Nester, Ph.D.
Extension Agent- IPM - Fire Ant Project
Texas Agricultural Extension Service
Harris County

Summary: The red imported fire ant, Solenopsis invicta Buren (herein referred to as the fire ant) has become an important economic threat in urban Texas. The fire ant affects recreational activities as well as agricultural operations. This trial evaluated two contact insecticides and one toxicant bait product, labeled for treatment of individual fire ant mounds. These mounds were located alongside a well maintained paved road which will represented the "hardscape." The treatments were applied May 15, 2000 when temperatures were moderate, moisture was good and fire ant activity was good. All products effectively reduced fire ant mound activity after 2 weeks. At three days the bait product reduced mound activity 48% but was not as efficient as the contact insectides which had reduced activity 100%. This trial demonstrates that toxicant baits products can be used as single mound treatments, but do not act as fast as contact insecticides.

Problem
The fire ant has become an important economic threat in urban Texas. According to a 1998 study conducted by the Department of Agricultural Economics, TX A&M University, of fire ant related costs in Dallas, Fort Worth, Austin, San Antonio, and Houston, fire ants have serious economic effects for these metro areas of Texas. Households experienced the largest costs among sectors examined with a average of $151 per households spent annually which included repairs to property and equipment, first-aid, pesticides, baits, and professional services. A full damage assessment for Texas must include additional sectors, and the estimated costs of $581 million per year for the selected sectors underscore the impact of this pest. Treatment costs accounted for over 50 percent of this total cost. In Houston the average medical treatment costs per household of $25.46. The duration of injury for children and adults was 6.6 days and 5.6 days, respectively. The fire ant limits outdoor activities and homeowners and producers incur added costs in managing the fire ant.

Objectives
This trial was established to evaluate Orthene® Fire Ant Killer Dust (50% acephate), Spectracide® Fire Ant Killer Granules (5% diazinon) and Amdro® Fire Ant Bait (0.73% hydramethylnon) for application to single fire ant mounds that have been established next to a hardscape (paved road). The trial was designed to observe the effectiveness of the materials in reducing fire ant activity over a 2 week period.

Materials and Methods
This trial was established in Houston, TX, in west Harris Co., May 15, 2000. Fire ant mounds were located on shoulders of a paved road where they were built close to the pavement. The site had been mowed before establishment of treated areas. Only trace amounts of rain fell the week proceeding the treatments but over 5.5 inches of rain fell during the 2 week duration of the test. Eighty active fire ant mounds were identified and marked in consecutive groups of five along the pavement. Each treatment was replicated 4 times and a treatment was randomly assigned a group of five mounds within each replicate.

The fire ant control products evaluated were the toxicant bait Amdro®, and contact insecticides, Orthene® and, Spectracide®. When used as a single mound treatment in open areas Amdro® usually provides control within 2-7 days of application, while control with Orthene® or Spectracide® occurs wthin hours. These products were applied as directed by label at the rates listed in Table 1 and the trial was set to run approximately 2 weeks.

At 3, 7 and 18 days after treatment (DAT) each mound was checked for presence or absence of fire ant activity. A small diameter stick was inserted into the mound. If no fire ants appeared after 15 seconds, the mound was considered inactive (0). If fire ants were present within the allotted time period the mound activity was assigned a 1 ( < 10 fire ants or freshly worked soil), 2 (some fire ants, not aggressive), or 3 (many aggressive fire ants).

Results
Table 1 shows the effectiveness of the materials during the evaluation period. All products controlled the fire ant 18 DAT. Amdro® treated mounds was reducing fire ant activity 3 & 7 DAT, but was not as effective as Orthene® or Spectracide® at these evaluation dates.

Conclusion
The results from this study indicate that the fire ant control products tested were effective in controlling fire ants that build mounds along a hardscape. The bait product, though effective reducing fire ant activity over a 2 week period was not as fast as the other products tested. However, bait products can provide relatively fast colony elimination when applied as individual mound treatments to inaccessible colonies, giving an acceptable reduction in fire ant mound activity within 2 weeks after application. Previous studies have shown slower suppression occurs after some bait products are broadcast-applied. A larger, replicated study is necessary to confirm the results of this demonstration trial.

Acknowledgments
The author would like to thank Dr. Bart Drees for his help in the establishment of the trial and Dr. Charles Barr for the statistical analysis of the data. He also appreciates American Cyanamid Company, and the Solaris Group of Monsanto Company for the opportunity to evaluate their products.

Table 1. Results of reduction in fire ant mound activity after treatment with different products labeled for fire ant control. Harris Co., TX, 2000.

Household Pest Ant Control by Homeowner
Scott A. Russell, Extension Agent: I.P.M.
Cooperator: Vicki McAlester

Summary: Vicki McAlester, a resident of Farmers Branch, had a household pest ant problem for an extended period of time. Numerous treatments Vicki had used only seemed to move the ants. Extension Agent Scott A. Russell suggested the use of a new bait station product and Mrs. McAlester agreed to work with Texas Agricultural Extension Service as a cooperator. Bait stations were placed along the ants' foraging trails in the kitchen and bathroom. Mrs. McAlester reduced her use of contact insecticides and has nearly eliminated the ants.

Problem
Mrs. Vicki McAlester had a problem with Pharaoh ants (Monomorium pharaonis) in her home. The ants first appeared in the kitchen, then after treating the ants using diatomaceous earth, they appeared in the bathroom. She contacted Texas Agricultural Extension for information. According to Mrs. McAlester she has had problems with ants for more than a year and had tried numerous methods including: contact insecticidal sprays, bait stations and diatomaceous earth products. Each time the ants seemed to move rather than be eliminated.

Objective
To teach homeowners the proper use of bait-formulated insecticides, thus reducing household exposure to contact insecticides.

Materials and Methods
MaxForce® FC Professional Insect Control Ant Bait Stations (fipronil) were provided by Karen Carlton, The Clorox Sales company. The home was inspected and significant ant activity was located in the kitchen pantry with several foraging trails throughout the kitchen area. Ants were found to have eaten through a closed bread bag, thus requiring that the bread be discarded. Ants were also located within the bathroom under the sink and around the bathtub. On August 9, 1999 several MaxForce® FC Professional Insect Control Ant Bait Stations were placed in various locations around the kitchen and bathroom. Stations were placed alongside foraging trails where ants were likely to find them. Ant trails were washed with warm soapy water and food sources removed. Mrs. McAlester was instructed not to use aerosol insecticides in the vicinity of these stations, since this will reduce their effectiveness by repelling the ants, and to be patient as baits are slower-acting than sprays. Ant specimens were collected and identification confirmed them to be Pharaoh ants.

Results and Discussion
After thirty days, there were noticeably fewer ants foraging. After sixty days the number of foraging ants began to rebound. The cooperator purchased new bait stations and replaced the previously installed stations in the infested areas. Vicki McAlester now reports that the ant numbers continue to drop. She has also reduced the use of insecticidal sprays.

Economic Analysis and Impact
Consumer ant bait stations vary in cost and availability. Clorox also manufactures a comparable consumer product under the name Combat® Quick Kill (fipronil). Depending on the outlet (and active ingredient), bait stations may cost between $0.55 and $2.99 each in the Dallas-Fort Worth area. At a median price of $1.22 each a single treatment using six bait stations would cost the consumer $7.32 (these might need to be reapplied). When compared to hiring a commercial pest control firm at prices ranging from $81.19 to $225.00 for a single treatment, a patient and diligent consumer can save a substantial amount of money.

Do-it-yourself pest control is not the answer for all pest problems. Hiring a professional may be appropriate in cases where individuals are sensitive to pesticides, in an area that is ecologically sensitive or when one has been unsuccessful at controlling a pest.

Conclusions
Pharaoh ants can be controlled in the home with less toxic ant-specific bait stations when used properly and when one is diligent to replace old, empty stations. Household pest ant control is often difficult because consumers are not patient enough to allow baits the appropriate amount of time to work effectively, and control may require multiple approaches. Professional pest control operators offer many different types of service including the use of baits, low impact control methods and insect specific products or application techniques. Persons doing pest control in a structure for hire must be licensed by the Structural Pest Control Board of Texas and individuals applying their own pest control must follow all label directions.

Acknowledgments: Appreciation is expressed to Vicki McAlester for her assistance and cooperation. Karen Carlton and The Clorox® Sales Company is thanked for providing materials and technical information about the MaxForce® line of products.

Evaluation of Three New Individual Mound Treatments for Fire Ant Control
M. E. Merchant and S. A. Russell
Texas Agricultural Extension Service
October 23, 2000

Abstract: Eleven treatments were applied to plots containing fire ant mounds at Dallas Fort Worth International Airport, Texas in March, 2000. Significant differences among the treatments were found in percent control, mound ratings, and rate of new, "satellite" mound formation. Treatments resulting in the greatest reduction of fire ant mound activity included diazinon and thiamethoxam. Greater than 95 percent control was obtained by by 1 and 7 days after treatment (DAT) in diazinon- and thiamethoxam-treated (1.2 g a.i./gal rate) plots, respectively. Complete (100%) control of fire ant mounds was observed by 14 DAT in both diazinon- and thiamethoxam-treated (1.2 and 2.4 g a.i./gal rates) plots. Although thiamethoxam appeared to work more slowly than diazinon, significant reduction in mound activity was evident by 1 DAT in thiamethoxam-treated plots. No control of fire ant mounds was observed with an experimental formulation of Beauveria bassiana (strain ATCC 74040) numbered as TB131-1. Observations of satellite mound formation in plots suggests that water drench- and Garden-Ville Soil Conditioner-treated colonies survived and moved to other locations more often than thiamethoxam-treated mounds.

Introduction
Individual mound treatments play an important role in fire ant management. Mound treatments are selective and often faster-acting than broadcast insecticide treatments (Merchant and Drees, 2000). One desirable characteristic of fire ant mound treatments is low toxicity. This test evaluated three relatively new, lower toxicity treatments: an experimental insecticide from Novartis Crop Protection, thiamethoxam (CGA 293343), a neonicotinoid class insecticide; Garden-Ville Soil Conditioner; and an experimental formulation of the fungus Beauveria bassiana (TB131-1). Although not registered as an insecticide, the Garden-Ville product is sold as an organic "soil conditioner" with fire ant control properties. Standard treatments included in the comparison were Amdro® Granular Fire Ant Bait, and Evict™ diazinon concentrate.

Methods and Materials
Forty-four plots, 40 feet wide and of varying lengths, were established on property belonging to Dallas Fort Worth International Airport adjacent to Hyatt Resort at Bear Creek Golf Course. Ground cover consisted of mixed forbs and grasses, which were left un-mowed over the course of study. Soil was predominately black clay. Eleven plots were located in each of four sites separated no more than 1 km. Active mounds were flagged prior to treatment, and each plot was sized to enclose approximately 10 active mounds. Plot length varied from 28 to 293 feet-long. Block assignments were based on plot length, with the 11 shortest plots assigned to block I, the next 11 shortest plots assigned to block II, etc. Treatments were randomly assigned to plots within blocks, according to a randomized complete block design with four replications. Mounds in each plot received one of the following treatments:

Pre-treatment counts were made on 17 March, 2000. Treatments were applied on March 20, 2000. Each mound was flagged and rated according to a scale modified from Lofgren & Williams (1982), where 1 = small mounds (less than 100 ants) and 5 = large mounds (>50,000 ants). Mounds containing fewer than 25 workers were considered inactive, and mounds less than 12 inches apart were considered a single colony. Mounds were counted and rated at 1, 3, 7, 14 and 28 days after treatment (DAT). New mounds discovered in plots after treatment were considered new or "satellite" mounds and were counted and rated as such. Results were analyzed using Statistical Analysis Software (SAS Institute, Cary, NC) Version 8.1. Significant differences were detected using the General Linear Models (GLM) procedure. Means were compared using Tukey's Studentized Range Test or the Ryan-Einot-Gabriel-Welsch multiple range test.

Results
Significant differences in mound activity were found on all post-treatment sample dates (P>0.05, GLM) (Table 1). Diazinon- and Garden-Ville-treated mounds had the lowest activity levels by one day after treatment (DAT); however by 3 DAT, a trend for lower percent active mounds was seen in thiamethoxam treated plots. By 7 DAT, percent active mounds were lower in all thiamethoxam-treated plots compared to Garden-Ville-treated plots. By 7 DAT ant activity was significantly lower for all thiamethoxam rates compared to control plots.

Complete control was achieved for two rates of thiamethoxam and the diazinon-treated plots. Thiamethoxam provided slower control, but the 1.2 g a.i./gal rate matched control provided by diazinon treatments by 14 DAT. Lowest levels of control were observed in plots treated with the fungal treatment, Beauveria bassiana. Fire ant activity in plots treated with this product were not significantly different from the untreated controls on all dates (P>0.05). Lack of control may have been due to the non-conventional method of application, which called for no use of water carrier. Hydramethylnon (Amdro®) treatments provided the slowest control, being indistinguishable from control plots until 7 DAT. By 14 and 28 DAT there was no statistical difference in control between Amdro® and the best treatments.

Comparison of mound ratings among the different treatments yielded results similar to percent activity measurements (Table 2). By 7 DAT mound activity ratings were lowest in diazinon- and thiamethoxam-treated plots. Mound ratings in control plots and Beauveria bassiana-treated plots were significantly higher than other treatments by 7 DAT. Numbers of satellite mounds in the plots increased over the two months of the study, and satellite mound numbers varied significantly among treatments (P=0.0028) (Table 3). Because there was no significant interaction between treatment and date (P=0.3835), all dates were combined for analysis.

Water drench, Garden-Ville, and Amdro treated plots showed the highest rate of satellite mound formation. Plots treated with the 1.2 g a.i./gal rate of thiamethoxam had significantly fewer satellite mounds than water drench- or Garden-Ville-treated plots. These data suggest that thiamethoxam treatments may be less likely to cause treated fire ant colonies to relocate and form satellite mounds, a desireable characteristic for a mound treatment.

Garden-Ville treated plots had statistically higher numbers of satellite mounds compared to plots treated with the 1.2 g a.i./gal rate of thiamethoxam, but there was no significant difference in satellite mound numbers between Garden-Ville-treated plots and untreated (no drench) control plots in this test. Overall fire ant activity, as measured by combined original and satellite mound ratings, produced results similar to those discussed previously (Table 4).

There was no consistent trend toward improved fire ant control with increased application rates of thiamethoxam. Overall, the 1.2 g a.i. rate of thiamethoxam provided numerically superior control and resulted in fewer satellite mounds than the higher, 2.4 g a.i./gal, rate. On most dates, however, there were no statistically significant differences between the two higher rates of thiamethoxam. The two lower rates provided levels of control equivalent to the higher rates except for on 1 and 3 DAT.

References cited
Lofgren, C. S. and D. F. Williams (1982). "Avermectin B1A: Highly potent inhibitor of reproduction by queens of the red imported fire ant (Hymenoptera: Formicidae)." Journal of Economic Entomology 75: 798-803.

Merchant, M. E. and B. M. Drees (2000). The Texas Two-Step Method: Do-it-yourself fire ant control for homes and neighborhoods. Texas Agricultural Extension Service publication L-5070.

Acknowledgments: The authors wish to acknowledge the Tarrant County and Dallas County Master Gardener volunteers, who contributed many man-hours of labor setting up, counting and rating fire ant mounds. We also thank the maintenance department of the DFW International Airport for their cooperation in supplying the site for the study.

Table 1. Effects of individual mound treatments on red imported fire ant (Solenopsis invicta) mound activity. DFW International Airport, Texas. 2000.

* Means followed by the same letter within a column are not significantly different (P<0.05, Ryan-Einot-Gabriel-Welsch Multiple Range Test). Analysis conducted on arcsine square root transformed data; original means are presented here.

Table 2. Effects of individual mound treatments on red imported fire ant (Solenopsis invicta) mound ratings. DFW International Airport, Texas. 2000.

* Means followed by the same letter within a column are not significantly different (P>0.05, Ryan-Einot-Gabriel-Welch Multiple Range Test).

Table 3. Effect of individual mound treatments on red imported fire ant (Solenopsis invicta) satellite mound development. DFW International Airport, Texas. 2000.

* Analysis conducted on square root-transformed data, original means presented. Data presented represent averages of satellite mounds for five post-treatment samples (1, 3, 7, 14, 28 DAT) combined for analysis. Means followed by the same letter within a column are not significantly different (P<0.05, Ryan-Einot-Gabriel-Welsch Multiple Range Test).

Table 4. Effects of individual mound treatments on overall activity of red imported fire ant (Solenopsis invicta) mounds in treated plots, including both satellite colonies and original treated mounds*. DFW International Airport, Texas. 2000.

* Based on a one to five rating scale where 1=25-100 ants, 2=100-1000 ants, 3=1000-10,000 ants, 4= 10,000 - 50,000 ants, 5= 50,000+ ants. ** n is the number of fire ant mounds evaluated, including both the original flagged mounds and additional satellite mounds that appeared after treatment. Means followed by the same letter within a column are not significantly different (P<0.05, Ryan-Einot-Gabriel-Welsch Multiple Range Test). Analysis conducted on arcsine square root transformed data; original means are presented here.

Evaluation of Potential Imported Fire Ant Quarantine Treatments
for Commercial Honey Bee Operations

Ronald D. Weeks, Jr., John G. Thomas, Charles L. Barr,
and Bastiaan "Bart" M. Drees, Department of Entomology,

Abstract. This research evaluated the efficacy of using a contact insecticide applied to the base or to the ground area around beehives in preventing red imported fire ant (Solenopsis invicta Buren) foraging on beekeeping equipment. Results from our field experiments on pallet and soil treatments shows that soil and/or support pallet applications of Lorsban 4E® (chlorpyrifos) are reasonable and effective techniques for preventing fire ant infestation or foraging on bee equipment for at least six weeks post insecticide application. Sampling over the six week period showed that vegetation such as grass and weeds could grow into natural "bridges" over treated pallets that ants can use to access bee equipment.

Introduction
Red imported fire ants (Solenopsis invicta Buren) can invade beehives and feed on pollen and developing bees. Weak bee colonies are more susceptible to ant invasions than healthy, vigorous colonies. Often, fire ants build their nests directly against or on beekeeping equipment. They typically use structures in contact with the ground for better colony thermoregulation and to escape localized flooding events. Fire ants can be transported in beehives or in soil adhering to hives and beekeeping equipment. Fire ant infestation of California's Central Valley has been linked to intra-continental transport of beehives for almond pollination. Consequently, beehives have recently become a regulated item by the United States Department of Agriculture (USDA). However, there are no currently established quarantine treatments approved for assuring that transported hives are fire ant free.

To date, there are no insecticides registered specifically for treating bee equipment to eliminate red imported fire ant foraging. However, there are several products on the market labeled for fire ants under a variety of specific conditions. For example, Lorsban 4-E® (chlorpyrifos) is an agriculturally approved contact insecticide for control of various insects, including red imported fire ants, in certain field, fruit, nut, and vegetable crops (e.g. alfalfa, orchard floors, field corn, popcorn, sweet corn, cotton, cranberries, sorghum, and soybeans). The objective of this study was to evaluate the efficacy of using a contact insecticide applied to a support pallet or the soil area around beehives in preventing fire ant foraging on beekeeping equipment.

Materials and Methods
Research was conducted September - October 2000 in Royalty Pecan Orchard - Burleson County, Texas. We used four treatments with four replicates of each treatment for a total of 16 sample units in a randomized block design to compare fire ant infestation levels among treatments. Treatments were randomly arranged under pecan trees in four blocks (i.e. tree rows) in one section of the orchard. The grass was mowed under each replicate unit before beehives and pallets were set up in the field. For this study, we used a typical commercial beekeeping set-up without the bees; hive pallet with clips and two hive supers with lids. In double pallet situations we added a support pallet with no hive clips.

Treatments comprised of: 1) spraying a 10 x 10 foot area of soil with Lorsban 4E® directly under a single beehive pallet; 2) a double pallet with the bottom support pallet sprayed with Lorsban 4E®; 3) a double pallet with no insecticide application; and, 4) a single pallet with no insecticide application. Lorsban 4E® was applied to the soil area and pallets according to label directions. Three locations were sampled for fire ants on and around each beehive unit using 3 by 3-cm olive oil-soaked bait cards. Two bait cards were set adjacent (ca. 20 to 30 cm) to each pallet on the ground, four bait cards were placed directly on the hive pallet and two were placed on top of the beehive boxes. A ranking system was used to record the approximate number of ants per bait card (i.e. 0 = zero ants, 1= 1 to 24 ants, 2=25 to 49 ants, 3=50 to 74 ants, 4 = 75 or more ants). We compared the means and standard deviations of the ranks of fire ant infestation levels at each sampling location for each treatment.

Results
Fire ant infestation levels were not significantly different between single and double pallet treatments in the absence of the contact insecticide (Figure 1). There were significant differences in fire ant infestation levels between non-insecticide treatments and insecticide treated pallets and soil applications, as indicated in non-overlapping standard deviations about the means respectively. In the double pallet (bottom pallet treated) insecticide treatment there were no fire ants found foraging on the pallets or the hives after six weeks post insecticide application, except in one sampling period. After four weeks post insecticide application a few fire ants were found on two bee pallets that were sitting on a treated pallet. Closer inspection revealed fire ants climbing on blades of grass, that crossed-over treated pallets, and onto untreated bee pallets. After removing these grass "bridges" no other ants were found on the bee equipment after subsequent sampling. Results from the soil insecticide application showed that fire ants were prevented from foraging on the ground area next to the bee equipment as well as on the bee equipment. During the last sampling period, which included a week of intense rainy weather, a few ants were found on a bait card on the ground next to one of the bee units. This indicates that the active ingredient in the insecticide was just beginning to degrade after six weeks post-insecticide application and several days of heavy rains.

Discussion
We have shown that soil or pallet application of Lorsban 4E®, a long-residual contact insecticide, is a reasonable and effective technique to prevent fire ant infestation or foraging on bee equipment for at least six weeks. Our results indicate that simply stacking beehive equipment on supporting pallets or similar structures does not eliminate or reduce fire ant foraging on bee equipment. Preventative barriers, such as chemical barriers, are necessary and effective in eliminating fire ant foraging on bee equipment.

Double pallet hive set-ups appear to have several advantages over single hive pallet set-ups. Support pallets can be treated with insecticides to prevent ant foraging on bee equipment and can reduce or eliminate time spent on hive pallet sanitation (i.e. soil removal) and may even extend the life of the hive pallet. However, sampling over time indicates that it is necessary to monitor and remove any bridges that may form across treated areas between the soil surface and the bee equipment, such as over-grown vegetation or fallen tree leaves and limbs. Soil applications of contact insecticides can be used in loading yards for short-term hive storage before moving to new locations.

By applying Lorsban 4E® to the soil surface or on a supporting pallet foraging honey bees can be protected from direct contact with the insecticide. Thus, making the use of contact insecticides a viable option for beekeepers as a potential quarantine treatment option. Future research is aimed at evaluating the behavior of ant colonies when placed on hives above treated pallets.

Acknowledgments: We thank Paul Jackson for bee equipment procurement and Andy Sherrod at Royalty Pecan Orchard for field site use and access. Funds for this project were provided to John G. Thomas, Executive Secretary Texas Beekeepers Association thorough the Texas Department of Agriculture and the Texas Imported Fire Ant Research and Management Project.

Evaluation of Potential Imported Fire Ant Quarantine Treatments for Hay Bales

Ronald D. Weeks, Jr., Michael E. Heimer, Charles L. Barr,
and Bastiaan "Bart" M. Drees, Department of Entomology,
Texas A&M University, College Station TX

Abstract. This research evaluated the efficacy of broadcast insecticide bait applications in hay production systems on the number and time of red imported fire ant (Solenopsis invicta Buren) infestations in hay bales in treated versus untreated field plots. Our results indicate that with a single broadcast bait application of an insect metabolic inhibitor (Amdro®, hydramethylnon) the number of hay bales infested with fire ants was significantly lower in treated plots compared to untreated plots. Cumulation curves of the number of bales infested over time indicate that near peak infestation levels occur within the first week of post-baling.

Introduction
Red imported fire ants (Solenopsis invicta Buren) frequently move into or next to bales of hay that have been left in the field after harvesting and can interfere with cutting, baling, handling and transporting hay. Typically, red imported fire ants build large hard-packed mounds above the ground, which can damage harvesting machinery. As a result, hay producers have to adjust the cutting heights on their harvesting machinery to avoid damage by mounds, resulting in reduced yields and increased harvesting costs. The United States Department of Agriculture (USDA) has listed hay as a quarantined agricultural product. Currently, there are no USDA approved quarantine chemical treatments for assuring that red imported fire ants are not shipped to new locations. Hay bales that are not removed from fields immediately after baling and stored in an off-ground location can not be shipped out of quarantined areas. There is little data to document how quickly or to what extent fire ants move into hay bales left in the field. There are no insecticides registered specifically for treating hay bales to eliminate red imported fire ants. However, Amdro® (hydramethylnon; an insect metabolic inhibitor) is a bait-formulated insecticide product registered for use in hay fields and livestock pastures. Yet, there is no data to document if hay fields treated with insecticide bait products can reduce or prevent hay from being infested by fire ants. This information is essential for the Texas Department of Agriculture (TDA) and USDA to improve and/or expand quarantine treatment options for bales of hay and straw. The objective of this research was to evaluate the efficacy of broadcast insecticide bait applications in hay production systems on the number and time of fire ant infestations in hay bales in treated versus untreated field plots. The directional hypothesis to be tested is that broadcast bait treatments significantly reduce or eliminate ant-infested hay bales in the field.

Materials and Methods
Research was conducted May - July, 2000 in Montgomery County, Texas. Four hay fields (2 square bale and 2 round bale), of at least 15 acres in size, belonging to 3 independent hay producers were used as replicate sites for this study. Each field was divided in half to make two plots of relatively equal size. One plot in each field was designated as an insecticide treatment plot, while the other plot was left untreated and used for ant infestation comparisons between treated and untreated areas.

To determine if there were any significant pretreatment differences in average ant densities between treated and untreated plots among fields, we counted the number of active mounds in 3 sampling circles (9.14 m radius) in each plot in May 2000. A two-tailed Wilcoxon non-parametric test showed that there was no significant differences in the mean number of active mounds between plots in all fields (S = 149, Z = -0.02897, P = 0.9769). The average number of active mounds per sampling circle was 20.8.

In each field, one plot was treated with a broadcast application of the insecticide bait product Amdro® (hydramethylnon), which is an insect metabolic inhibitor, to establish large areas where ants were suppressed or eliminated in May 2000. The broadcast insecticide application rate was 1.5 lbs. per acre as directed on the label. The smallest area treated in a field was 5 acres. We compared both round and square bale operations. In the round bale operations, four sets of hay bales comprised of five round bales per set were left in each plot after hay baling (5 bales x 4 sets x 2 plots per field = 40 round bales per field). In the square bale operations, four random sets of hay bales comprised of ten square bales per set were left in each plot after hay baling (10 bales x 4 sets x 2 plots per field = 80 square bales per field). Three locations on each hay bale were sampled for fire ants using 3 x 3 cm Olive oil-soaked bait cards (e.g., one card on two sides and one on the top). Sampling was conducted at four separate times after baling (1 - 3, 4 to 8, 9 to 11, and 12 or more days). The number of infested hay bales per set of bales was recorded for each sampling period. We used the total number of hay bales, per set of bales, infested with red imported fire ants after being in the field for 12+ days as our response variable. Due to the absence of normality in the data and the directionality of our hypothesis, we combined the data from both square and round bale operations into a single data set for a non-parametric test. We used a directional Wilcoxon rank sum test to test the hypothesis that broadcast bait treatments significantly reduce or eliminate infested bales in both square and round hay bale operations. Also, cumulation curves were generated to determine when (over time) and to what extent infestations occurred.

Results
Using a single treatment application, we were not able to eliminate fire ants from the hay production operation. However, results of the Wilcoxon rank sum test support our directional hypothesis that after a single broadcast application of the insect metabolic inhibitor, Amdro® (hydramethylnon), the number of infested hay bales in treated areas was significantly reduced compared to untreated areas (Table 1). Graphs of the number of hay bales infested over time in each treatment indicate that ants begin to move onto or into hay bales within the first day or so and that near peak infestation levels occur within the first week of post-baling (Figure 1).

Discussion
A single broadcast application of Amdro® in hay fields significantly reduced the level of hay bale infestations in treated areas. However, it did not eliminate the fire ant problem entirely. This type of result suggests that not all colonies were eliminated in treated areas. Previous work has shown that periodic broadcast applications of fire ant baits provide roughly 90 percent suppression of ants when properly applied. Our results show that hay bales become infested within the first 1-3 days, reaching near peak infestation within a week. This infestation rate may be enhanced by mound and colony disturbance through normal harvesting and baling practices. Also, fire ants are known to move colonies next to upright-exposed structures for better colony thermoregulation and to escape localized flooding events. In the field, hay bales may provide a variety of microclimates which fire ants, and other arthropods find appealing; such as thermoregulation sites, flood refuges, moisture under bales during drought, and the presence of both shady and sunny areas along the sides. Given that we were not able to eliminate fire ants from our treatment plots we are encouraged by our initial results using a single application of Amdro®. Based on these significant results we are continuing studies to assess the long-term efficacy of broadcast bait applications in a repeated application program of treatment. Our goal is to develop reasonable treatments to assure shipment of ant-free hay bales from ant-infested to non-infested areas of the country.

Acknowledgments: Funding for this research was provided to Michael Heimer, County Extension Agent, Agriculture, Montgomery County, Texas through the Texas Department of Agriculture and the Texas Imported Fire Ant Research and Management Project. Thanks to Dr. White, Mr. Berkeley, and Mr. Huber for the hay and field sites and to Mr. Kyle Miller at American Cyanamid for the Amdro® donation.

Table 1. Results of a Wilcoxon rank sum test comparing the mean number of hay bales, per set of bales, infested with red imported fire ants after 12+ days in insecticide treated versus untreated hay fields. N = sixteen sets of hay bales in each treated and untreated area, of these eight sets comprised ten square bales per set and eight sets comprised five round bales per set in each treated and untreated area.

Fig. 1. Cumulation curve of ant infestation on hay bales after baling, Montgomery Co., TX, 2000.

Evaluation of Certain Fire Ant Insecticide Products and Tactics in a Nursery Situation Cooperator: Sterling Beck, Evergreen Nursery
Gary Bomar and Chris Sansone, Ph.D.
County Extension Agent-Agriculture and Extension Entomologist
respectively, Texas Agricultural Extension Service
Taylor County

The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant affects nursery operations by causing handling and shipping problems. In addition, the ant can disrupt drip irrigation lines and cause mechanical problems in electrical switches. This preliminary report discusses the impact of two different insecticides on fire ant populations. Both Amdro® (hydramethylnon) and Logic® (fenoxycarb) give good fire ant control six weeks after treatment. The Amdro® and Logic® mixture was comparable to either product by itself. The check plot also had few existing mounds which indicates that fire ants have difficulty maintaining large populations even under limited water conditions.

Problem
The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant is not only a people problem but has economic impacts on nursery enterprises. The ant affects nursery operations by reducing efficiency of labor and thus increasing labor costs. Plant material cannot be shipped to non-quarantined counties if fire ant infested and thus increases costs of plant materials if fire ants are a problem.

Objectives
This trial was established to evaluate two insecticides labeled for fire ant control in a nursery operation. The trial is designed to measure the effectiveness of the materials as well as the length of control.

Materials and Methods
This trial was established in a nursery situation in the Abilene in Taylor County. The nursery site served as a tree farm for a local nursery. The site had both container plants and trees planted in rows. Water was provided by drip irrigation as well as supplemental irrigation in individual pots. The materials evaluated were Amdro® and Logic®. Amdro® contains 0.73% by weight hydramethylnon. The insecticide acts on the metabolism of the ant making it difficult for the ant to produce energy. Amdro® usually provides control within six weeks of application. Logic® contains 1.0% by weight fenoxycarb, a carbamate which acts as an insect growth regulator that mimics the juvenile hormones in insects. Insect growth regulators are usually slower to act but provide a longer period of control in other fire ant trials.

In addition to these two products, an additional tactic was also tried. The field was divided into four sections and four treatments were applied. Amdro® was applied in a solid pattern in the first section at a rate of 1.5 lbs per acre. The next section was left untreated. The third section was treated with Logic® in a solid pattern at a rate of 1.5 lbs per acre. The fourth section was treated with a combination of Amdro® and Logic® in a solid pattern. The combination rate was 1.5 lbs per acre or 0.75 lbs per acre each product. The plots were treated on September 22, 1998 to coincide with Fire Ant Awareness Week.

Results
The results show the effectiveness of the materials at six weeks and 8 months after treatment. The data also shows the impact of dry weather on imported fire ants in the West Texas region. Even though this site had some supplemental irrigation to keep the trees alive, the winter of 1998-1999 was characterized by dry conditions. Moisture conditions improved later in the spring of 1999 but plots were not evaluated after 8 months.

The test shows a couple of interesting aspects of fire ant control in West Texas. First, the dry conditions can have a devastating impact on fire ant populations. This site had some supplemental irrigation and so the ants were not totally deprived of water. However, the untreated check plot still suffered 90 percent mortality during the 8 months of the trial. Second, the baits are highly efficacious when used properly. The baits are best used as a broadcast treatment and not on an individual mound treatment. The cost of the baits and the slow results with the baits do not make them the ideal choice for individual mound treatments. The baits should also be used when the ants are actively foraging. This can be determined by placing a small amount of bait next to an active mound. If ants are actively foraging, the ants will find the bait in a short amount of time (less than 10 minutes).

This trial also shows the advantage of fall applications of insecticides for fire ant control. The weather can limit populations as evidenced by the 90 percent decline in the untreated plots. When an insecticide is used in the fall, the homeowner benefits from both the weather and chemical control. The combination treatments are not currently labeled. This treatment was evaluated because many homeowners are dissatisfied with the slower acting growth regulators and want the faster knockdown that Amdro® can provide. The advantage of the growth regulators is that they usually provide longer control (less rebuilding of mounds). When conducted properly, fire ant control is possible for the homeowner. Many baits are now available that effectively control fire ants in an urban setting.

Acknowledgments
The authors would like to thank Sterling Beck for the use of his nursery to conduct this trial.

Table 1. Results of control at six weeks and 8 months after treatment of different insecticide control. Taylor Co., TX. 1999.

Evaluation of Fire Ant Insecticide Products
Jerry Kidd and Chris Sansone, Ph.D.
County Extension Agent-Agriculture and Extension Entomologist
respectively, Texas Agricultural Extension Service
McCulloch County

The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant affects recreational activities as well as agricultural operations. This trial evaluated an experimental bait formulation compared to a commercially available product. Neither product provided adequate control compared to the untreated check plot. This trial was initiated July 1,1998 when temperatures were high and fire ant activity was minimal. Results demonstrate that even with effective materials, homeowners must still apply baits at the proper time.

Problem
The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant is not only a people problem but has economic impacts on agricultural enterprises. The ant limits outdoor activities and homeowners and producers incur added costs in managing the ant.

Objectives
This trial was established to evaluate one insecticide labeled for fire ant control and an experimental product around a recreational area. The trial is designed to measure the effectiveness of the materials as well as the length of control.

Materials and Methods
This trial was established in a recreational area near Brady in McCulloch County. The site was near a lake shore and heavily infested with imported fire ants. Amdro® contains 0.73% by weight hydramethylnon. The insecticide acts on the metabolism of the ant making it difficult for the ant to produce energy. Amdro® usually provides control within six weeks of application. Amdro® was applied at the rate of 1.5 lbs of product per acre and the experimental acephate bait formulation was applied at the rate of 42 lbs per acre. Due to secrecy agreements, the percentage of acephate in the bait is unknown. Acephate, is a quick acting contact insecticide that when directly applied to the mound provides relatively quick control.

The site was divided into 12 approximately equal sections. Each section was 65 feet long and 50 feet wide. The treatments were replicated four times and evaluated on a weekly basis for four weeks.

Results
The results show the effectiveness of the materials during the evaluation period. Both products appeared to give quick initial knockdown but after the evaluation period, the treated plots were not statistically different from the untreated plot.

The test shows a couple of interesting aspects of fire ant control in West Texas. First, the dry conditions can have a devastating impact on fire ant populations. This ants had easy access to water so drought is not the whole explanation for the decline. However, the untreated check plot still suffered 40 percent mortality during the 4 weeks of the trial. Second, the baits are highly efficacious when used properly but performance can be limited when applied at the wrong time. The baits are best used as a broadcast treatment and not on an individual mound treatment. The cost of the baits and the slow results with the baits do not make them the ideal choice for individual mound treatments. The baits should also be used when the ants are actively foraging. This can be determined by placing a small amount of bait next to an active mound. If ants are actively foraging, the ants will find the bait in a short amount of time (less than 10 minutes).

Table 1. Results of control of fire ants after treatment of different insecticide control. McCulloch Co., TX. 1998.

* Plots treated on July 1, 1998. Data were transformed to reduce variation and then transformed back for this report.

Evaluation of Certain Fire Ant Insecticide Products and Tactics in a Landscape Situation
Cooperator: Schleicher County Scott Edmonson and Chris Sansone, Ph.D.
County Extension Agent-Agriculture and Extension Entomologist
respectively, Texas Agricultural Extension Service Schleicher County

The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant affects haying operations by reducing efficiency of machinery, increasing labor costs and impacting final yields. The imported fire ant also affects the use of landscape and park areas. This report discusses the impact of three different insecticides on fire ant populations. Both Amdro® (hydramethylnon) and Logic® (fenoxycarb) give good fire ant control six weeks after treatment. This trial also evaluated the Texas Two-Step method under drought conditions. The check plot also had few existing mounds which indicates that fire ants have difficulty maintaining large populations even under limited water conditions.

Problem
The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant disrupts the use of rural and urban landscapes with their constant foraging and defensive behavior. The ant affects landscape operations by reducing efficiency of labor and thus increasing labor costs. Plant material is difficult to maintain and the ants can affect drip irrigation lines.

Objectives
This trial was established to evaluate the Texas Two-Step method and two insecticides labeled for fire ant control in the landscape. The trial is designed to measure the effectiveness of the materials as well as the length of control.

Materials and Methods
This trial was established in a landscape site in Schleicher County. The site evaluated was the courthouse flower beds in Eldorado. The flower beds are part of a beautification project on the courthouse square. Four mounds from each treatment were sampled to determine if the ants were imported fire ants or native ants.

The materials evaluated were Amdro® and Logic®. Amdro® contains 0.73% by weight hydramethylnon. The insecticide acts on the metabolism of the ant making it difficult for the ant to produce energy. Amdro® usually provides control within six weeks of application. Logic® contains 1.0% by weight fenoxycarb, a carbamate which acts as an insect growth regulator that mimics the juvenile hormones in insects. Insect growth regulators are usually slower to act but provide a longer period of control in other fire ant trials. The baits were applied on June 3, 1999.

In addition to these two products, the Texas Two-Step method was evaluated. This method relies on bait applications followed by the application of a standard insecticide to kill nuisance mounds. The standard in this case was Orthene® Fire Ant Killer which contains the active ingredient, acephate. This "second step" was applied as a dust one week after the baits to control the nuisance mounds.

Results
All the mounds sampled were imported fire ants (Table 1). The results show the effectiveness of the materials at six weeks after treatment. The data also shows the impact of dry weather on imported fire ants in the West Texas region. Even though this site had some supplemental irrigation to keep the plants alive, rainfall was insignificant after the first week in June of 1999 was characterized by dry conditions.

The test shows a couple of interesting aspects of fire ant control in West Texas. First, the dry conditions can have a devastating impact on fire ant populations. This site had some supplemental irrigation and so the ants were not totally deprived of water. However, the untreated check plot still suffered 96 percent mortality during the 6 weeks of the trial. Second, the baits are highly efficacious when used properly. The baits should only be used as a broadcast treatment and not on an individual mound treatment. The cost of the baits and the slow results with the baits do not make them the ideal choice for individual mound treatments. The baits should also be used when the ants are actively foraging. This can be determined by placing a small amount of bait next to an active mound. If ants are actively foraging, the ants will find the bait in a short amount of time (less than 10 minutes).

The combination treatments are not currently labeled. This treatment was evaluated because many homeowners are dissatisfied with the slower acting growth regulators and want the faster knockdown that Amdro® can provide. The advantage of the growth regulators is that they usually provide longer control (less rebuilding of mounds). When conducted properly, fire ant control is possible for the homeowner. Many baits are now available that effectively control fire ants in an urban setting.

Economic Analysis
Since the introduction of fire ants to the United States, there has existed the misnomer that the treatment of fire ants was too costly for a homeowner to justify treatment. Although in a pasture or range situation this may be true, the homeowner can treat for a minimal amount. The cost figures for each product used is listed in Table 2 with an estimated cost to treat a 2000 square foot lawn. As the data shows, this is not as costly as many would presume.

Acknowledgments
The authors would like to thank Schleicher County for permission to use the courthouse site to conduct this trial.

Table 1. Results of control at six weeks after treatment of different insecticide control. Schleicher Co., TX. 1999.

Table 2. Estimated Cost Figures For Treating A 2000 Foot Square Lawn For Fire Ants.

Evaluation of Certain Fire Ant Insecticide Products and Tactics in a Haying Situation
Cooperator: Judge Walter Prugh
Mike Mallett, Jason Johnson, Ph.D. and Chris Sansone, Ph.D.
County Extension Agent-Agriculture, Extension Economist and Extension Entomologist
respectively, Texas Agricultural Extension Service Lampasas County

The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant affects haying operations by reducing efficiency of machinery, increasing labor costs and impacting final yields. This preliminary report discusses the impact of two different insecticides on fire ant populations. Both Amdro® (hyrdamethylnon) and Extinguish® (s-methoprene) give good fire ant control six weeks after treatment. The Amdro® and Extinguish® in a solid pattern provided the comparable control. The field will be evaluated during the winter and spring of 2000 to determine the length of control of the two products.

Problem
The imported fire ant, Solenopsis invicta Buren, has established itself as an important economic pest in Texas. The ant is not only a people problem but has economic impacts on agricultural enterprises. The ant affects haying operations by reducing efficiency of machinery, increasing labor costs and impacting final yields. Some producers feel that the cost of fire ant control can be too high especially if the level of control is poor.

Objectives
This trial was established to evaluate two insecticides labeled for fire ant control in hay pastures. The trial is designed to measure the effectiveness of the materials as well as the length of control. Economic analysis will also be conducted to determine if fire ant control can be economical.

Materials and Methods
This trial was established in a hay field in the eastern part of Lampasas County. The materials evaluated were Amdro® and Extinguish®. Amdro® contains 0.73% by weight hydramethylnon. The insecticide acts on the metabolism of the ant making it difficult for the ant to produce energy. Amdro® usually provides control within six weeks of application. Extinguish® contains 0.5% by weight methoprene, an insect growth regulator that mimics the juvenile hormones in insects. Insect growth regulators are usually slower to act but provide a longer period of control in other fire ant trials.

In addition to these two products, different tactics were also tried. The field was divided into four sections and four treatments were applied. Amdro® was applied in a skip swath pattern in the first section. Research indicates that the ants will travel to forage for food. The Amdro® was applied in a thirty foot swath and then thirty feet were skipped. This pattern resulted in 0.75 lbs of Amdro® applied per acre. The next section was treated with Extinguish® in a solid pattern at a rate of 1.5 lbs per acre. The third section was treated with Amdro® in a solid pattern at a rate of 1.5 lbs per acre. The fourth section was treated with a combination of Amdro® and Extinguish® in a solid pattern. The combination rate was 1.5 lbs per acre or 0.75 lbs per acre each product.

Results
The results are preliminary and more data need to be collected in the spring of 200 before results are final. Table 1 shows the level of control for each of the treatments at six weeks and 5 months after application. Plots were treated on May 21, 1999 and evaluated on June 29, 1999 and again on October 7, 1999. Amdro® gave the greatest level of control at 6 weeks followed by the Extinguish® and combination of Extinguish® and Amdro®.

The skip swath of Amdro® did not provide the expected control at 6 weeks when compared to other research plots. The skip swath treatments may be better with a growth regulator like Extinguish®. The Amdro® and Extinguish® provided high levels of control. Extinguish® is difficult to evaluate at 6 weeks because it is slower acting. Mounds were considered under control if no brood was evident in the mounds. The combination treatment worked well but needs to be evaluated over a longer time period. The advantage of this treatment should be in longer control compared to Amdro® used alone. All the plots had 100% control after 5 months but this was probably a function of weather. The control pasture located next to the treated pasture had a 95% reduction in mounds.

Economic Analysis
This trial also compared the cost of a sickle mower to a disk mower when used in a pasture that is fire ant infested. There was no significant difference in time to operate the two mowers in the pasture treated for fire ants although the disk mower is somewhat faster and more efficient to operate (Table 2). In the untreated pasture, the sickle mower took three times longer to mow the same acreage and forage yield was reduced by twenty percent with the sickle mower. Yield was reduced due to the mounds causing the sickle blade to bounce and leave large swaths uncut. The use of a sickle mower in a fire ant infested field added an addition $5.40 per acre (Table 3). All costs increased. If the producer considers the cost of operating a sickle mower plus the cost of reduced yield then the additional $8.00 per acre for fire ant control is easily justified. The other alternative is to purchase a disk mower/conditioner. Since the disk mower is cheaper to operate at $1.03 per acre, the operator should be able to recover costs after harvesting approximately 1,900 acres.

Conclusion
The test does show that fire ant control is possible despite the number of complaints about the use of baits. The baits are highly effective when applied properly. The baits should only be used when the ants are foraging. This can be determined by placing a small amount of the bait next to an active mound. If the ants are foraging, they will start feeding on the bait within 5 to 10 minutes. The baits need to remain dry for 24 hours. The presence of a heavy dew did not affect the performance of this trial. However, a rain over 0.5 inches would dictate that the baits should be reapplied. Baits should also be used when soil temperatures are above 65 degrees Fahrenheit.

Baits should be used once in the spring and once in the fall. The fall applications are important because the combination of the bait and the winter temperatures can reduce populations in the spring to very low levels. The trial also shows the devastating impact of dry conditions on fire ants. The treated pasture was treated again on October 7, 1999 to determine if populations can be kept at low levels in the spring.

Acknowledgments
The authors would like to thank Judge Prugh for the use of his field to conduct this trial. Thanks are also extended to Dr. Charles Barr for his input and suggestions for the trial. We would also like to thank Wellmark for the Extinguish®.

Table 1. Preliminary results of control at six weeks after treatment of different insecticide control. Lampasas Co., TX. 1999.

Table 2. Estimated machinery cost (per acre) for disk mower and sickle mower in the absence of fire ants. Lampasas Co., TX. 1999.

Table 3. Estimated machinery cost (per acre) for a sickle mower in the absence and presence of fire ants. Lampasas Co., TX. 1999.

Evaluation of Extinguish® for Fire Ant Control in
Pecans article for The January 001 Issue of "THE PECAN PRESS"
Bill Ree, Extension Agent - IPM (Pecans) and
Allen Knutson, Ph. D., Professor and Extension Entomologist

This month's article is the second of a two part series on the impact of fire ants in a pecan management system. In last month's article we reviewed the results of a survey/questionnaire that was distributed to 305 Texas producers and homeowners during 2000. This month's column will summarize some of the field data collected during 2000 from two study sites.

Problem
The red imported fire ant, Solenopsis invicta Buren, commonly infests pecan orchards in central Texas. Growers report that stinging ants are a hazard to orchard workers grafting trees and during harvest. Fire ants also damage equipment such as irrigation lines and electric motors on water pumps and in the orchard, ants can enter open sutures in the shells of fallen nuts to feed on kernels. Although no formal assessment of economic impact has been made, a recent survey found that 35 percent of the commercial growers invest $6.00 or more per acre annually to control fire ants in their orchards.

Until recently, pecan growers had few options for controlling fire ants in pecans. Lorsban® 4E (chlorpyrifos) is registered for application to the orchard floor to temporarily reduce fire ant numbers. Studies have shown that Lorsban 4E sprayed onto tree trunks also reduce the number of fire ants entering the canopy. Logic® (fenoxycarb) fire ant bait is registered only for use in non-bearing pecan orchards.

The active ingredient in Extinguish® fire ant bait is an insect growth regulator (IGR) called methoprene. When transported back to the colony by foraging fire ants and fed to the queen, the queen stop producing viable eggs and the colony slowing dies out. The label for Extinguish states it "may be applied to, but not limited to, parks, zoos, school grounds, pastures, rangeland, citrus groves, cropland," and many more sites (see label). Because of this extensive listing of approved application sites, Extinguish is viewed as potential product for fire ant control in pecans.

Project Objective
Measure the impact of fire ant control on densities of key aphid predators and aphid densities throughout the season on pecans.

Methods and Materials
To investigate the objective of this study, two commercial orchards were selected, one was the Bill Haney Orchard in Comanche County and the second orchard was the Holmes Pecan Orchard in Robertson County near Mumford, TX. At each orchard, twelve subplots were established within the orchard and each plot was randomly assigned to one of the following three treatments: Extinguish® fire ant bait, Lorsban® 4E trunk spray, or the untreated check.

Comanche County: Plots consisted of 12 rows of trees with about 22 trees in each row. Trees were spaced 25 ft apart in the row and rows were 30 ft apart, resulting in plots about 330 ft by 550 ft or 4.5 acres for each plot.

Robertson County: Plots consisted of eight rows of trees with nine trees in each row. Tree spacing was 45 by 45 ft. This resulted in plots 315 by 360 ft or 2.6 acres each.

Treatments. Extinguish was applied at a rate of 1.5 lbs per acre using a Herd spreader attached to all terrain vehicle. The swath width was about 30 feet and the application speed about 10 mph. Comanche County: Extinguish was applied once in October 1999, and twice in 2000 on June 16 and October 3. Lorsban 4E was applied at a rate of 1 pint/100 gallons of water with a hand gun attached to a roller pump and tank in the back of a pickup truck. Lorsban was applied until run-off to the trunk from the soil level up to a height of about 3 feet. Treatment dates for Lorsban 4E were October 1999 and May 3, August 8 and October 18, 2000. Robertson County: Extinguish was not applied until May 19, 2000 with a second application on October 12, 2000. Lorsban 4E was applied on May 12, July 24 and October 12, 2000.

Treatment Assessment. The effect of each insecticide treatment on fire ant densities was measured by counting mounds, trapping ants in food-baited vials and pitfall traps and counting ants on tree trunks. The impact of treatments on other arthropods was measured by counting aphids on leaves, sampling lacewings with cardboard bands, and sampling insects and spiders by fogging the tree canopies with a pyrethroid insecticide. Each method is described below.

Mound density. Ant mounds were not visible for counting in Comanche county due to dry weather in Oct. 1999, when the first insecticide treatments were made. Rains in late October were followed by mound building activity and allowed mound densities to be determined on Nov. 2. On this date the number of fire ant mounds were counted in two subplots each 30 by 25 ft in each plot. Mound densities were determined again the following summer on June 19, 2000 by counting the number of mounds in an area 12 ft wide and centered down the row of five trees (125 ft long). Fire ant colonies were concentrated along the drip irrigation line running between trees. No significant rainfall occurred from June through Oct. 2000, and mounds were not visible for counting until rains returned in early Nov. 2000. Mound densities were determined Nov. 12, 2000 in a subplot 125 ft long and 30 ft wide in each plot. Mound diameter was also recorded.

Mound densities were not recorded in Robertson County until March 30, 2000. Mound densities were made by counting the number of mounds in a subplot 12 ft wide and centered down a row of five trees (225 ft) in each plot. Mound density counts were repeated in the same locations on June 27, July 25 and Dec. 7, 2000.

Ant Density at Baits. Foraging ants were sampled using glass vials containing a piece of Tender Vitals® cat food and a piece of Jolly Rancher® gum drop candy. A single vial was placed on the ground about 12 inches from the trunk of three trees in the center of each plot. On the same three trees, a single vial was placed in the crotch of the tree to sample ants entering the canopy.

Direct sampling. Tree trunks in each plot were visually searched for one minute and all ants collected with an aspirator and later identified.

Pitfall sampling. Four pitfall traps were placed about three feet at each cardinal point around three consecutive trees in each plot. Pitfall traps are used to sample arthropod activity on the orchard floor and as a means to sample for native ants which may not inhabit a tree but do compete with foraging fire ants on the orchard floor. Pet safe antifreeze was added to the bottom of the pitfall trap to kill and preserve ants and other arthropods falling into the trap.

Lacewing/spider sampling. Bands of single sided corrugated cardboard about one inch wide and three inches long were wrapped once around a terminal branch and fastened together with a plastic clothespin. The cardboard bands were a means to monitor lacewing and spider populations within the tree canopy. Lacewing larvae enter the corrugations and pupate. Spiders also construct webs inside the corrugations. A total of 10 bands were placed in each of five consecutive trees in the center of each plot. Bands remained in the orchard for about one week and then were collected and opened to observe lacewing larvae, pupae or spiders.

Results
Not all of the samples or data have been sorted or analyzed at this time. For this article, only information on mound density, aphid populations and predator collections will be discussed.

Mound density - Comanche County: In November, 1999, the average number of mounds per two subplots was 9, 9, and 11.5 for the Extinguish®, Lorsban® and check treatments, respectively. Mound densities were not significantly different, confirming the expectation that the treatments applied two weeks earlier had not yet reduced mound density. At an average density of 9.8 mounds/subplot, the density of mounds was 300 per acre prior to treatment.

The following summer (June 19, 2000), densities of fire ant mounds averaged 46, 152 and 232 per acre for Extinguish®, Lorsban® and the check, respectively. This represents an 80 percent reduction in mound numbers in the Extinguish treatment and 35 percent reduction in the Lorsban treatment, relative to the check. The reduction in mound density in the Lorsban treatment may have resulted from direct exposure of colonies at the base of the trunks to the Lorsban trunk treatment. Also, ant colonies may have died due to lack of access to food in the tree canopies. An examination of the colonies for brood (immature ants) found 38 percent of the colonies in the Extinguish treatment lacked brood while only 2 to 3 percent of the colonies in the Lorsban and check lacked brood.

Fire ant densities in November, 2000, averaged only 32 per acre in the Extinguish treatment, an 89 percnet reduction compared to a density of 287 mounds per acre in the untreated check. Densities in the Lorsban treatment were 238 mounds per acre, or 17 percent less than the check.

Mound density - Robertson County. On the initial ant mound count date, March 30 the number of mounds across the twelve plots averaged 271 mounds per acre. By the second mound density count on June 27, mound counts fell to and average of 46 mounds per acre in the Extinguish® plots, while the Lorsban® and check plots averaged over 166 mounds per acre. On July 25, mound density in the Extinguish plots averaged 25 mounds per acre while the Lorsban and Check plots averaged 133 and 241 mounds respectively. By December 7 following some heavy November rains mound counts in the Extinguish plots rose to an average of 79 mounds per acre while the Lorsban plots increased to 192 mounds and the Check stayed about the same at 237.5 mounds per acre.

Lacewing/spider sampling - Robertson County: The sampling of aphid predators, primarily lacewing and spiders with cardboard bands was conducted from May 23 through September 2000. The population trend of lacewings and spiders followed the same pattern as the aphid populations, peaking on June 27 then falling off during the remainder of the season.

Pecan aphid density - Robertson County: Most of the information on pecan aphid population trends came from Robertson County where weekly counts were made from May 30 through September. Population trends followed the same pattern in all treatments, regardless of fire ant numbers. However, it should be pointed out that the full impact of the Extinguish® treatment had not come into play by the time aphid populations peaked. In all plots, aphid populations peaked on June 26 then crashed to low numbers by the next sample date of July 5.

Summary
Comanche County: The fall application of Extinguish® resulted in an 80 percent reduction in densities of fire ant mounds the following June. Mound densities were reduced by 89 percent in November following a second application in May. It is also noted that those remaining mounds in the Extinguish plots were much smaller in size than mounds in the Lorsban® and check plots.

Robertson County: Fire ant mound densities in December were reduced in the Extinguish® plots by 74 percent while mound density counts in the Lorsban® and check plots were reduced only 28 and 5 percent respectively when compared to the pretreat count in March. Pecan aphid populations in the three treatment areas followed the same pattern of peaking in late June then dropping to low numbers in early July. Collections of lacewings and spiders in cardboard bands also followed the same pattern as the aphid populations. However, the initial application of Extinguish and its effect on fire ant populations and the possible impact on aphid predators and aphid populations had not come into play during the time on increased aphid activity (June) so no conclusion can be made at this time on that interaction.

As an added note, from the collection of ants in baited vials and pitfall traps during the season, 18 new county records for ant species were recorded for Robertson and Comanche counties.

Acknowledgment:
The authors would like to acknowledge several people for with out their work this project would not have been possible. Alejandro Calixo for spending countless hours in the field and lad collecting data and sorting through samples; Jennifer Begnaud for her assistance in collecting data and tabulating survey information and Bob Whitney - County Extension Agent - Comanche County for his assistance in applying treatments and collecting data. The authors would also like to recognize and thank Bill and Peggy Haney, Haney Pecan Orchard and Robert Kwiakowski, Homes Pecan Orchard for allowing this project to be conducted in their orchards.

Evaluation of Extinguish®, Distance®, Combination of
Distance and Amdro® and the Two-Step Method for
Suppression of Red Imported Fire Ants in Turf

Glen C. Moore
Extension Agent-Entomology
Cooperator: Heritage Baptist Church

Summary: This trial evaluated the performance of 2 new IGR baits, Extinguish® (s-methoprene) and Distance® (pyriproxyfen) at 1 lb/ac and a combination of Distance at 0.5 lb./ac plus Amdro® (hydramethylnon) at 0.5 lb./ac and the Two-Step method employing Extinguish at 1 lb./ac followed by individual mound treatments of Orthene® 75S (acephate) at 2 tsp./mound for suppression of red imported fire ants in turf. These treatments were applied in the spring of 1999 and compared to an untreated check.

The Two-Step Method and the combination treatment of Distance® and Amdro® afforded a significantly higher reduction in mound numbers at 2 weeks after treatment. At six weeks after treatment, there was not observed to be a significant difference in the reduction of mound numbers between Distance, the combination treatment of Distance and Amdro and the Two-Step Method. Results were the same at 12 weeks after treatment, with these treatments being significantly different than Extinguish® and the untreated check. A fall inspection made at 22 weeks after treatment revealed that Extinguish, Distance, the combination treatment of Distance plus Amdro and the Two-Step Method were all equally efficacious and significantly better than the untreated check.

Problem
The red imported fire ant, Solenopsis invicta, is prevalent throughout the North Central Texas area where they are a nuisance, interfering with man's activities and sometimes their sting is cause for medical concerns. Although management of fire ants around urban areas is highly desirable, some treatment options are costly. Additionally, registration of new IGR baits, Extinguish® and Distance® warrant testing to determine short term and long term efficacy.

Objective
The primary objective was to evaluate the performance of the new IGR baits, Extinguish® (s-methoprene) and Distance® (pyriproxyfen), as well as a combination treatment of Distance and Amdro® (hydramethylnon) and the Two-Step Method employing Extinguish followed by individual mound treatments of Orthene® 75S (acephate) in comparison to an untreated check. Equally important, was to compare the cost of treatments.

Materials and Methods
On April 20, 1999, broadcast applications of Extinguish® at 1 lb./ac, Distance® at 1 lb./ac, and a combination treatment of Distance at 0.5 lb./ac plus Amdro® at 0.5 lb./ac, were made to 1/4 acre plots on the Heritage Baptist Church grounds near Waxahachie, Texas. Additionally, Extinguish at 1 lb./ac was broadcast over same size plots as the initial phase of the Two-Step Method. To complete the Two-Step treatment, individual mound treatments were made to active mounds by applying 2 tsp's of Orthene® 75S directly to mounds. Application of baits were made with a hand-held scatter box calibrated to deliver 1 lb of bait material per acre. Treatments were replicated three times in a randomized fashion.

Plots measuring 1/4 acre each, were created by staking one end of a string measuring 58 ft in length in the center of individual plots to be designated and with the string stretched walking in a circular pattern around the plot. Pre-treatment mound densities were recorded for each plot prior to treatment. Post-treatment inspections were made by recording the number of active mounds per 1/4 acre plots at 2, 4, 6, 8, 12 and 22 weeks after treatment. Data was submitted to Dr. Charles Barr, Extension Program Specialist - Fire Ant Project, for analysis.

Results
Only the Two-Step Method employing Extinguish® at 1 lb./ac followed by individual mound treatments of Orthene® 75S at 2 tsp. and the combination of Distance® at 0.5 lb./ac and Amdro® at 0.5 lb./ac provided a significantly higher reduction in active mound numbers at 2 weeks after treatment (Table 1). During the sixth through twelve week period after treatment, there was not observed to be a significant difference in the reduction of mound numbers between Distance, the combination treatment of Distance and Amdro and the Two-Step Method. All three were equally efficacious being significantly different than Extinguish® and the untreated check. A fall inspection made at 22 weeks after treatment revealed that Extinguish, Distance, the combination treatment of Distance plus Amdro and the Two-Step Method were all equally efficacious and significantly better than the untreated check. Percent reduction in mound numbers at 2, 6, 12, and 22 weeks after treatment and the cost per acre for treatments are illustrated in Table 2. Reduction in mound numbers in the untreated check was largely the result of hot and dry conditions during July, August and September.

Economic Analysis
The per acre cost for a broadcast application of Extinguish®, Distance®, and the combination treatment of Distance plus Amdro® varied only slightly ranging from $11.78/ac to $11.88/ac. While the Two-Step Method provided the most immediate reduction in mound numbers, it was the most expensive with Extinguish at $11.88/per acre plus Orthene® 75S costing $0.19 per mound.

Conclusion
The new IGR baits, Extinguish and Distance, was observed to be highly efficacious as fire ant control agents. Although Extinguish did not provide a significant reduction in mound numbers until after 12 weeks, it ultimately provided long term control equal to that of Distance, the Two-Step Method employing Extinguish plus Orthene 75S and the combination treatment of Distance plus Amdro.

Acknowledgments:
Much gratitude is extended to Heritage Baptist church for serving as demonstrating cooperator. Appreciation is also extended to the following representatives and companies for product availability: Mr. Doug VanGundy of Wellmark International and Ms. Pam Kanoekfi of Valent. Also, a special thanks is due Dr. Bart Drees, Extension Fire Ant Coordinator and Dr. Charles Barr, Extension Program Fire Ant Specialist for data analysis.

Table 1: Efficacy of Extinguish™, Distance®, a combination of Distance plus Amdro® and the Two-Step Method employing Extinguish and Orthene® for red imported fire ant suppression of ornamental turf in comparison to an untreated check, Heritage Baptist Church, Ellis County, Texas, 1999.

* Means with the same letter are not significantly different, Analysis of Variance, Tukey's Studentized Range (HSD) Test for Variance

Table 2: Percent reduction in mound numbers at 2, 8 and 22 weeks after treatment and cost per acre for three fire ant bait treatments and the Two-Step method, Heritage Baptist Church, Ellis County, Texas, 1999

Evaluation of Chemical Management of Fire Ants
Final Report 1999
Jerry L. Cook, Ph.D., Department of Entomology,
Texas A&M University, College Station, Texas 77843-2475

This is the first year in a project designed to determine the best method of chemical control of the red imported fire ant, Solenopsis invicta Buren, on Texas Army National Guard firing ranges. This project is an evaluation of commercially available fire ant baits that can be used in conjunction with biological control (which is being evaluated in another research project) to form an integrated pest management plan for control of the red imported fire ant. This project ran experimental tests using three commercially available baits: methoprene, an insect growth regulator or IGR (trade name Extinguish®); abemectin, a nerve-active toxicant (trade name Advance®); and hydramethylnon, a metabolic inhibitor toxicant (trade name Amdro®). To test these products, four National Guard sites were chosen, with differing climates and imported fire ant densities. Sites used were Camp Swift (near Bastrop), Fort Wolters (near Mineral Wells), Camp Bowie (near Brownwood), and Camp Maxey (near Powderly). At each site four test replications were conducted. Each replication included a toxicant, an insect growth regulator, and a control. At two of the sites, Camp Swift and Fort Wolters, treatments were made in the fall of 1998 and the spring of 1999. At the other two sites, treatments were made in the spring of 1999.

The goal of this project is to determine what type of bait is most effective at controlling the red imported fire ant on firing ranges. Another goal is to determine if the most environmentally safe control, should more than one product being tested be equal in control capability. The result of this test and evaluation will provide the Texas National Guard with an informed choice in managing red imported fire ants on firing ranges. A continuation of this project is designed to take into account the yearly differences in climate and how it effects control provided by these products.

Materials and Methods
At each of the four sites (Camp Swift, Camp Bowie, Camp Maxey, and Fort Wolters), 12 test plots were chosen on existing firing ranges. Plot size was approximately ¼ acre. The plots were established by selecting a center site and measuring out a radius of 60 feet to make a circular ¼ acre. These sites were chosen in blocks of three, each plot in the block being similar in fire ant density and each occurring on the same firing range. Four of these blocks made up the treatment sites at each National Guard location. Thus, there were a total of 48 treatment plots. Within each block, plots were randomly assigned a treatment of control, an insect growth regulator, and a toxic bait (Amdro® at two sites and Advance® at two sites).

Prior to treatment a census of fire ant colonies was made. To do so, all ant mounds were flagged, checked for activity, and all active mounds were counted. Treatments were then made at the maximum label rate. The rates applied were 1 lb./acre for Advance® (0.011% abamectin B1); 1 ½ lb./acre of Amdro® (0.73% hydramethylnon); and 1 ½ lb./acre Extinguish® (0.5% (S)-methoprene). Checks on fire ant activity and active mounds were made at regular intervals after the test and, at 16 weeks post application final counts of active mounds were made for that treatment. These final counts were used for comparison of bait efficacy. This time frame of determining when to evaluate the efficacy of the baits was chosen because of previous test results on these baits preformed by the Department of Entomology, Texas A&M University. These tests determined that nearly all of the control that would be provided by these baits would be complete in this time frame. Fall 1998 tests were conducted in October at Camp Swift and Fort Wolters. Spring tests were conducted in March and April at all four sites. Results of efficacy of treatments and comparisons of treatments were analyzed using t-tests and ANOVAs as appropriate.

Results
Camp Swift. Initial mound counts, before the fall treatment, on test plots ranged from 49 mounds to 101 mounds. This translates to a fire ant density of between 196 to 404 mounds/acre. In all bait treatments, fire ant mound density was significantly reduced (P = < 0.001). The untreated control mound density remained statistically the same (P = 0.915). However, the best control still left 6 percent of the fire ant mounds active. The reduction of fire ant mounds in bait treatments ranged from 94 to 63 percent. Mound densities of treatment areas ranged from 4 to 21 mounds per plot. Statistically, there was no difference between treatments of Advance® (abemectin) and Extinguish® (methoprene), but both were significantly lower than the control. In the spring of 1999, fire ant colonies within the same test plot had increased to nearly the levels of pretreatment in the fall. These new colonies were from new colony establishment and movement of existing colonies into the test plot area. The number of colonies at pre-treatment spring 1999 were lower than pre-treatment fall 1998, although not significantly different (P = 0.271). Colonies again were reduced in the spring after treatment, this time to densities ranging from 0 to 11 mounds per plot. While these numbers are numerically different, they are not significantly different (P = 0.078 and P = 0.094). Test results for Camp Swift are given in the following table:

Fort Wolters. Initial mound counts, before the fall treatment, on test plots ranged from 6 mounds to 52 mounds. This translates to a fire ant density of between 24 to 208 mounds/acre. In all bait treatments, fire ant mound density was significantly reduced (P = 0.01 to P = 0.03). The control mound density remained statistically the same (P = 0.985). The best control eliminated fire ant mounds, but fire ant densities in some plots still existed up to 4 mounds per plot active. The reduction of fire ant mounds in bait treatments ranged from 100 to 88 percent. Mound densities of treatment areas ranged from 0 to 4 mounds per plot. Statistically, there was no difference between treatments of Amdro® (hydramethylnon) and Extinguish® (methoprene), but both were significantly lower than the control. In the spring of 1999, fire ant colonies within the same test plot had increased to nearly the levels of pretreatment in the fall. These new colonies were from new colony establishment and movement of existing colonies into the test plot area. The number of colonies at pretreatment spring 1999 were lower than pretreatment fall 1998, although not significantly different in the Extinguish® plots (P = 0.374), but were significantly lower in the Amdro® plots (P = 0.141). Colonies again were reduced in the spring after treatment, this time to densities ranging from 0 to 1 mound per plot, while controls were not significantly different. Test results for Camp Swift are given in the following table:

Camp Bowie. Initial mound counts, before the spring treatment, on test plots ranged from 42 mounds to 67 mounds. This translates to a fire ant density of between 168 to 268 mounds/acre. In all bait treatments, fire ant mound density was significantly reduced (P = <0.0001). The control mound density remained statistically the same (P = 0.968). The best control did not eliminate fire ant mounds, but reduced densities to a range of 8 to 13 mounds per plot. The reduction of fire ant mounds in bait treatments ranged from 84 to 77 percent. Statistically, there was no difference between treatments of Amdro® (hydramethylnon) and Extinguish® (methoprene), but both were significantly lower than the control. Test results for Camp Bowie are given in the following table:

Camp Maxey. Initial mound counts, before the spring treatment, on test plots ranged from 6 mounds to 102 mounds. This translates to a fire ant density of between 24 to 408 mounds/acre. The fire ant mound density was significantly reduced (P = 0.043) in the Advance® treatment plots. The plots treated with Extinguish® were numerically reduced from a mean of 47 to a mean of 7 mounds per plot, however this reduction was not statistically different (P = 0.062). The control mound density remained statistically the same (P = 1.000). The best control did not eliminate fire ant mounds, but reduced densities to a range of 1 to 21 mounds per plot. The reduction of fire ant mounds in bait treatments ranged from 87 to 78 percent. Statistically, there was no difference between treatments of Advance® (abemectin) and Extinguish® (methoprene) (P = 0.445), but both were significantly lower than the control. Test results for Camp Maxey are given in the following table:

Exact location of sites on specific firing ranges for all of the above data is available if needed. These plots will continued to be used as this project continues in coming years.

Discussion
Both treatment types reduced fire ant densities and, although there were slight differences in the treatments, all bait treatments appear to control fire ants at approximately the same level. One trend is evident, in that with high mound densities (such as densities above 200 mounds per acre) there are still a large number of ants that are not eliminated with these treatments. In high-density plots, approximately 80 percent of the mounds were eliminated, but 20 percent of the original number is still a large number of ants. If the mound density were exactly 200 mounds per acre (equal to 50 mounds in one of the test plots) and 20 percent were left after treatment, there would still be 40 mounds per acre. Since these mounds probably average over 100,000 ants per mound, this is a large number of ants (100,000 X 40 = 4 million) that can potentially sting troops using the firing ranges. The reason that larger numbers of ants are left in these high-density plots may be that there is simply not enough bait to effectively eliminate all the ants present. However, baits were applied at the maximum label rate. The solution here appears to be to in some way reduce numbers to lower densities by other means, such as biological controls and, then eliminate ants not affected by these biological controls with baits which would yield relatively fire ant free firing ranges. In plots where densities were low, densities were reduced to very low numbers of colonies, or in some cases completely eliminated. The other means to control these high densities of ants is to persuade companies to increase their legal maximum label rates. However, this option is undesirable because it means introducing larger amounts of chemicals into the environment.

One interesting result of this study is in the results of differences between a one time treatment such as the first fall treatment at Camp Swift and Fort Wolters and follow-up treatments, as occurred at Camp Swift and Fort Wolters in the spring. In the situations where a later, follow-up treatment was made, ant density was below the original starting point (although only statistically different at Fort Wolters). This lower starting point allowed for ants to be reduced further with the second treatment than had been observed in the initial treatment. A continued treatment program may reduce these even further and make it possible to essentially eliminate ant colonies for at least some time between treatments. However, as long as there are other ant populations in the vicinity, fire ants will continue to move back into the treated area and, baits have no residual effect to keep these new intruders out.

One drawback of the broadcast treatment regime described above is that not only are fire ants eliminated, but other ants are also eliminated. These baits are essentially attractive to most ants and since native ant species are almost always in fewer densities, it is much easier to eliminate them. When all ants are eliminated from an area surrounded by fire ant infestation, it is the fire ants that are able to more easily re-establish in the ant free area, and in doing so, to exclude other ant species. The red imported fire ant appears to be the master of the ant world in taking over disturbed habitat. The result of this is that a management program must be continued or fire ants will become established at even higher densities than before the treatment regime.

Acknowledgments
I would like to thank Steve Simms, Whitmire Microgen, for providing Advance® bait and, Doug VanGundy, Wellmark International, for providing Extinguish bait for this project.

Release and Attempts to Document the Establishment of
Natural Enemies of the Red Imported Fire Ant Final Report 1999
Jerry L. Cook, Ph.D.
Department of Entomology, Texas A&M University, College Station, Texas 77843-2475
(Current address: Department of Biology, Sam Houston State University, Huntsville, Texas 77341-2116)

A number of natural enemies that occur with the red imported fire ant, Solenopsis invicta Buren, in South America have been identified that can potentially reduce populations of this pest species in the southern United States. Among those biological control candidates is a group of parasitic flies in the genus Pseudacteon (family Phoridae). Thus far, only one of the species of Pseudacteon has been approved for release in the United States. Dr. Sanford Porter, USDA-ARS, Gainesville, FL, has determined that Pseudacteon tricuspis is host specific to S. invicta (Porter et al. 1995a). With the documentation provided by Dr. Porter, P. tricuspis has been approved for release in the United States. Releases have been made by Dr. Porter at several sites in Florida, South Carolina, Georgia and Alabama. Releases have also been made near Laredo, Texas by Dr. Larry Gilbert, University of Texas.

Pseudacteon tricuspis is a fly whose larvae develop in the head of the red imported fire ant (Porter et al. 1995b). The female P. tricuspis deposits an egg near the inter-segmental membrane of the head of a red imported fire ant worker ant. The egg hatches, and the fly larvae go through their larval development inside the head of their hosts. The fly larvae feed on the tissues of the fly head. After the larval stage is completed the fly pupates and causes the head of its host to fall off. The head is then removed from the ant colony by other worker ants. The pupal stage lasts about two weeks, after which the adult fly emerges. Mating occurs after emergence and flies then hover around fire ants until eggs are deposited (Morrison et al. 1997).

The effects of this parasitization can be detrimental to red imported fire ant populations in two ways. First there is some direct impact by the killing of worker ants, although not enough to alone manage fire ants. There is also a behavioral impact caused by this association. When phorid flies are attacking fire ants, they cause a behavioral change in the foraging activities of the worker ants (Orr et al. 1995, Porter et al. 1995c). Ants tend to not forage when the flies are around. This decreases the amount of resources provided to fire ant colonies and allows other ant species to better compete for existing resources. Thus, a more even competition exists between native ant species and red imported fire ants (Porter et al. 1997).

The control of red imported fire ants in the United States has thus far used chemicals in management efforts. However, there are several reasons to turn to biological control to help in this management effort. First, the use of large amounts of chemicals needed to control fire ants is potentially harmful to the environment and, therefore, undesirable. Second, the continued use of chemicals is a costly, and temporary, solution to the problem. Third, treatment with some chemicals eliminates not only fire ants, but also other ants. After treatment, it is fire ants that are the first to return to the area and they are then able to keep out other ants and monopolize available resources. In the long term, chemical treatments can favor the increase in populations of fire ants. Finally, the only solution to reducing populations of fire ants is to provide a sustained pressure that is specific to fire ants. The logical way of doing this is to bring the natural enemies of the fire ant into their environment. This project is an attempt to do just that. We have begun to evaluate whether P. tricuspis can establish in Texas at the training sites used by the Texas Army National Guard. This is just one of several natural enemies that may be needed to actually provide management of red imported fire ants.

This is the first year of this project. The initial step of this program is to determine if P. tricuspis will establish in Texas. The reason for this evaluation is that it is not certain whether P. tricuspis will adapt to the Texas climate and be able to sustain a population using the polygyne form of the red imported fire ant. In Texas, fire ant colonies are predominantly polygynous, whereas in its native South America, populations are largely monogyne. One result of this situation is that ant workers tend to be smaller in polygyne colonies and P. tricuspis must have a certain size of worker in order to develop females (Morrison et al. 1999).

Materials and Methods
Pupae of Pseudacteon tricuspis were obtained from Dr. Sanford Porter, USDA-ARS, Gainesville, FL. Dr. Porter shipped about 5,000 heads to the Center for Urban Entomology, Texas A&M University. These pupae were still enclosed in their fire ant host's head capsule. The pupae were kept in 10 by 10 by 10 inch plexiglass cages with fine netted openings for ventilation. The pupae were placed in petri dishes filled with dental stone and the dental stone was kept moist. Other moist dental stone was placed in the cage to maintain a relative humidity of over 80 percent to facilitate emergence. The cages were kept at room temperature. Flies emerged begining about a week after the arrival of the pupae and upon emergence they were transported to the release site. Flies emerged and were released over a period of 3 weeks.

The release site was a site near permanent water at Camp Swift, near Bastrop, Texas. This site was a quarter acre plot, with a fire ant density of over 250 mounds per acre of polygynous imported fire ants. A second, similar site was set aside as an untreated control site to evaluate effects of the phorid flies, should they successfully establish. Prior to making releases, surveys were made of ant populations at both plots using bait traps and pit-fall traps. Baits were placed in test tubes with a piece of wiener as an attractant. After 30 minutes the test tubes were capped and taken to the laboratory for identification and counting of ants. A total of 25 bait stations were used at each site. Pit-fall traps used cups with propylene glycol that were left in the soil for three days and then collected for counting and identification of ants. A total of 15 pit-fall traps were used at each site.

Releases were made by placing a large plastic box (20 by 10 by 10 inch) over a fire ant mound and putting a canvas tarp above the box to shade the sun. The mound was disturbed and flies were introduced under the box. The mound was disturbed about every 15 minutes (or more frequently if fire ants became inactive) for a period of two hours. Observations were made to insure that the phorid flies were ovipositing on ants. All releases were started between 10:30 am and 12:00 noon.

One month after releases surveys were made by disturbing mounds and checking for phorid fly recruitment. These surveys were made for approximately one hour during each check and used several mounds for observation. Checks were made approximately twice a month for the first two months and once a month afterwards.

Results
Densities of the two plots were similar. The pit-fall samples have more native ants than do bait stations and will be used in evaluations in future years of this project, it the phorid flies are shown to establish. Bait station collections were used to show relative numbers of fire ants between the two plots and will also be used in the evaluation of effect on fire ants should the phorid flies establish. These results showed that the two plots were statistically similar (P = 0.399). The results of bait sampling are presented in Table 1 (all counts are of Solenopsis invicta, except those noted as otherwise). Phorid flies were released between April 8, 1999 and April 24, 1999. A total of 3,350 flies were released. Table 2 gives the number of flies released on each date, along with release conditions. Sampling for establishment and the occurrence of a field generation began one month after the final release. For the first two months of sampling, checks were made approximately bi-weekly. After that time, checks were made approximately monthly. Table 3 provides the results of those checks.

Discussion
Dr. Sanford Porter has determined that at least 1,500 phorid flies are required to make a successful release (personal communication). The number that I released (3,350) easily was enough to establish phorid flies if conditions were right for them. I released flies over a period of approximately 3 weeks to allow for the possibility of a continuous population emerging. My idea was that if the flies that I released oviposited soon after their release, then a continuous population of phorid flies might result. The reason that these flies were released over a 3 week time-span was so that I could determine that later observations were from a field population and not a released population. Pseudacteon tricuspis adults live for only about 5 days and the development time is 5 or more weeks. The difference in development time is dependent on environmental temperature.

My results show that P. tricuspis established through at least one field generation. After this time, I have not observed flies for about two months. This does not mean that the population is still not active, but they have not been observed. Sanford Porter has had a population established for nearly 2 years in Florida and there are times when he does not observe them for some time (personal communication). Therefore, the success of this release can not be determined for some time and even if the population has been lost, there is still the chance for a future establishment of another population. The results of finding at least one field generation shows that there is the potential for establishment.

There are several factors that may be detrimental to the establishment of Pseudacteon tricuspis. First, P. tricuspis must have a certain size of ant do develop a female. In Texas, most red imported fire ant colonies are of the polygynous form, which have smaller workers than the monogyne form. There are some workers that are large enough to allow for females to develop in polygynous red imported fire ants, but that percentage is around 10 percent of the colony. One question that has not been researched is how good P. tricuspis is at searching for proper hosts to develop a sufficient number of females. Many insect parasites are very good at host determination, but no work has been done on this phorid fly species. This is a project that should be investigated, but it would take funding for basic research. Second, Texas has a distinct dry period during each year and this is not encountered in P. tricuspis' native range in Brazil. There has been no research on whether this will affect their establishment. Third, P. tricuspis appears to attack almost always at disturbed mounds. This limits their encounters with red imported fire ants, especially in mid-summer, when most of the ant population is deep in the soil and active mostly at night. However, this is also the case in Florida, where Sanford Porter has populations that have established through this period. There are other phorid species that attack imported fire ants primarily on foraging trails, but these species have not yet been approved for release in the United States.

The evaluation of this release will become clearer in the next year and I plan to release more P. tricuspis to supplement this population, or try to re-establish it. There is also a possibility that other phorid fly species or strans may be approved for release and these could be added to the management plan.

References cited

Morrison, L. W., C. G. Dall'Aglio-Holvorcem, and L. E. Gilbert. 1997. Oviposition behavior and development of Pseudacteon flies (Diptera: Phoridae), parasitoids of Solenopsis fire ants (Hymenoptera: Formicidae). Environmental Entomology 26(3): 716-724.

Morrison, L. L., S. D. Porter, and L. E. Gilbert. 1999. Sex ratio variation as a function of host size in Pseudacteon flies (Diptera: Phoridae), parasitoids of Solenopsis fire ants (Hymenoptera: Formicidae). Biological Journal of the Linnean Society 66: 257-267.

Orr, M. R., S. H. Selke, W. W. Benson, and L. E. Gilbert. 1995. Flies suppress fire ants. Nature 373: 292-293.

Porter, S. D., H. G. Fowler, S. Campiolo, and M. A. Pesquero. 1995. Host specificity of several Pseudacteon (Diptera: Phoridae) parasites of fire ants (Hymenoptera: Formicidae) in South America. Florida Entomologist 78(1): 70-75.

Porter, S. D., M. A. Pesquero, S. Campiolo, and H. G. Fowler. 1995. Growth and development of Pseudacteon phorid fly maggots (Diptera: Phoridae) in the heads of Solenopsis fire ant workers (Hymenoptera: Formicidae). Environmental Entomology 24(2): 475-479.

Porter, S. D., R. K. Vander Meer, M .A. Pesquero, , S. Campiolo, and H. G. Fowler. 1995. Solenopsis (Hymenoptera: Formicidae) fire ant reactions to attacks of Pseudacteon flies (Diptera: Phoridae) in southeastern Brazil. Annals of the Entomological Society of America 88(4): 570-575.

Porter, S. D., D. F. Williams, R. S. Patterson, and H. G. Fowler. 1997. Intercontinental differences in the abundance of Solenopsis fire ants (Hymenoptera: Formicidae): escape from natural enemies? Environmental Entomology 26(2): 373-384.

Table 1. Counts of ants collected at bait stations left in plots for 30 minutes. All counts are of Solenopsis invicta, unless noted otherwise.

Table 2. Conditions for phorid fly releases and the numbers of flies released on given days.

Table 3. Monitoring of phorid flies at the release site. Dates and conditions are shown along with numbers of phorid flies observed.

Target-Specific Fire Ant Suppression for Preservation of Native Species
and Non-Target Organisms such as the Horned Lizard
Jerry L. Cook, PhD
Department of Biological Sciences, Sam Houston State University, Huntsville, Texas 77341-2116

The red imported fire ant, Solenopsis invicta Buren, has spread through the southeastern United States during the past 80 years, since its accidental introduction into Mobile, Alabama. Because Solenopsis invicta was introduced without its natural enemies, and is an aggressive predatory species, it has wrecked havoc with indigenous populations ranging from small invertebrates to man (Porter et al. 1997). This invasion has decimated the indigenous ant fauna primarily by competitive replacement (Porter and Savignano 1990). This then allowed S. invicta populations to continue to expand to the point where it is commonly found at levels of higher than 100 mounds per acre, and has been recorded at over 1,000 mounds per acre (Jerry Cook unpublished data). This high density of fire ants is capable of damaging the biodiversity of many ecosystems (Porter and Savignano 1990).

One apparent casualty of the S. invicta invasion appears to be the Texas Horned Lizard, Phrynosoma cornutum, which is now listed as a threatened species in Texas and Oklahoma. Phrynosoma cornutum relies almost exclusively on a diet of harvester ants from the genus Pogonomyrmex (Blackshear and Richerson 1999). The harvester ants are being directly impacted by S. invicta, along with many other ant species (Porter and Savignano 1990, Mann 1994, Pennisi 2000). There may also be some direct effect on the Texas horned lizard by S. invicta, since ingestion of fire ants is toxic to many species due to its alkaloid poisons (Contreras and Labay 1999). However, it is uncertain if P. cornutum will feed upon S. invicta. The effect of S. invicta on Pogonomyrmex harvester ants and the Texas horned lizard is just one example of a much greater problem that the red imported fire ant is causing for ecosystems throughout the southeastern United States.

In October 1998 a program sponsored by the Texas Army National Guard was started to determine how to best eliminate fire ants from training facilities (specifically Camp Swift, Camp Bowie, Camp Maxey, and Ft. Wolters) and not further harm the natural ecosystem. The challenge of this project was to eliminate S. invicta while not harming native species, including closely related native ants. The common practice of using broadcast baits for fire ant treatment is unsuitable for this type of project because native ants will also feed on these toxic baits and, by eliminating S. invicta, native ants could also be removed. A broadcast bait program may not only eliminates native ants that are important to the ecosystem (Folgarait 1998), but this in turn can remove the only real competitors of S. invicta. After the elimination of ant competitors, new S. invicta colonies usually move back into the empty niche and are then able to exist at much higher population levels than before the chemical treatment. The other drawback to this chemical treatment regime is that it can be expensive and put toxic chemicals into the environment. Therefore, the Texas Army National Guard program had as a goal to find a way to manage S. invicta without eliminating other native species. To evaluate the results of the program, Pogonomyrmex species populations were monitored.

The concept of this program was to find a technique to use commercially available ant baits and to apply them in a way that would not impact other species. In turn, if this program were a success, it would conserve populations of Texas horned lizards, harvester ants, and other native species. In the first year of this program, a prescription treatment method was identified that appeared to effectively manage fire ants while not impacting native ants.

This program continued in the Army National Guard fiscal year 2000 with the goal of evaluating the program developed in the previous year and to attempt to conserve harvester ant and Texas horned lizard populations. The four sites being utilized for this program all had harvester ant populations at the start of the study. The harvester ant species found at all of these sites was Pogonomyrmex barbatus (F. Smith) and Camp Swift had an additional species, Pogonomyrmex comanche Wheeler.

Pogonomyrmex comanche is becoming a rare species and may be more in danger of extinction than even P. cornutum (Jerry Cook unpublished data). This ant species was historically found in several sandy regions of central Texas and Oklahoma (Cole 1968, Taber 1998). It has now been eliminated from most of these historical regions and has only been positively identified at two current locations, Lost Pines State Park (near Bastrop, Texas) and Camp Swift. Presumably, the reasons for its decline are habitat loss and, direct competition and predation by S. invicta. The status of P. comanche was unknown before this project. Pogonomyrmex barbatus is also being impacted by the same pressures as P. comanche, but it also occurs outside the invasion area of S. invicta and has a much larger range. Thus, it is not presently threatened, but its populations are declining, as are most ants in the area invaded by S. invicta.

Materials and Methods
Sites for experimental and control plots were selected at Camp Swift, Fort Wolters, and Camp Bowie. Plots were not selected at Camp Maxey because no harvester ants were found. Each plot contained fire ant mounds and native ants including mounds of harvester ants, Pogonomyrmex sp. (in all cases the harvester ant species was P. barbatus, but at Camp Swift a site was selected that also included P. comanche). Treatment and control plots were comparable in habitat type and relative ant density. The plots were separated by at least 100 feet to provide a buffer zone between treatment and control. The plot size was at least ½ acre and was marked with stakes that remained throughout the test. At each National Guard site, there was a treatment plot and a non-treatment (control) plot.

Prior to any treatments a survey was conducted to establish ant populations. For this survey, pitfall traps and bait traps were used. Nine evenly spaced pitfall traps were used in each plot. These traps consisted of tubes submerged in the soil, so that their opening is at ground level. The tubes were partially filled with a propylene glycol solution that is safe to vertebrates that might get into the traps. The propylene glycol acted as a killing agent and preservative for invertebrates, and will not quickly evaporate. Control and test sites had pit-fall traps utilized for the same period of time. Traps were collected, taken to the laboratory and all ants were identified, counted and recorded. Bait traps consisted of putting a test tube baited with meat (Vienna sausage) onto the ground. Nine of these traps were evenly spaced and put in each of the test plots for about 45 minutes. The vials were capped, taken to the laboratory, frozen, and the ants were then identified, counted and recorded.

Prior to treatments all fire ant mounds within the plot were located and flagged. Mounds were counted and recorded. The S. invicta mounds in the treatment plots were then individually treated by sprinkling 1 to 5 tablespoons of bait product around the mound, depending on mound size. Treatments were made using Amdro® (hydramethylnon), a slow acting stomach poison. Re-treatments were made at a later date to any existing fire ant mounds within the treatment plot. Control plots had mounds identified, counted and recorded.

Surveys were made approximately 3 months later in the same manner as the pre-survey. This time frame is such that control of fire ant should be achieved, if control occurs. The results were compared with the pre-survey populations. A more meaningful comparison will be made one year after treatment, in fall 2000. This survey will be at the same time, seasonally, as the initial survey and will be a more accurate comparison to pre-treatment conditions. However, this will occur in the next year cycle and the earlier analysis was used to complete the final report for this funding year. To get an accurate assessment of this program, it will have to run for more than one year to allow ant populations to adjust to changed conditions, such as relatively fire ant free areas of the treatment plots. Plots will continue to be treated and monitored after the initial survey to allow for this continuance. Any decrease in a native ant species will be evaluated and determined if it is a probable result of the treatment method.

Results
Camp Maxey. At the beginning of this project in 1998 there were only a small number of harvester ants, Pogonomyrmex barbatus, present at Camp Maxey (1999 final project report). All of these harvester ants were in regions associated with firing ranges where a program has now been going for the past two years to control fire ants using broadcast bait applications. In the process of these treatments all P. barbatus have been eliminated. This year, I extensively surveyed Camp Maxey for additional harvester ants, but none were located.

Camp Swift. Camp Swift has the unique distinction among Texas Army National Guard training facilities of having two harvester ants, Pogonomyrmex comanche and P. barbatus. These ants are living sympatricly at one site, which was used as the test site for this program. This site is located at N 30° 16.786', W 97° 19.133'. Another population of P. comanche is located at N 30° 17.087', W 97° 18.571'. These two sites are 1.06 Km apart, but there are no other harvester ants in between. Because reproductive flights are usually less than this distance, these two populations are most likely isolated. There are several other areas that have P. barbatus in small colonies within Camp Swift, including sites near the headquarters building. A treatment for fire ants was made on April 20. There were only 8 S. invicta mounds found within the treatment plot. This is a decrease from 35 mounds in spring, 1999 and 22 mounds in fall, 1999. Previous treatments were made after the fall 1999 mound counts. The control site went from 33 S. invicta mounds in spring, 1999 to 38 mounds in spring 2000. Only 18 S. invicta mounds were observed in fall 2000, but the area was still in a severe drought, and many mounds may have been missed. All harvester ants are now gone from the control site (originally there were 6 P. comanche and 4 P. barbatus mounds). Harvester ants present in the treatment plot started in spring, 1999 at 12 colonies of P. comanche and 4 colonies of P. barbatus. By fall, 2000 these numbers had changed to 11 colonies of P. comanche and 2 colonies of P. barbatus. Mating flights of P. comanche were witnessed on June 15 at Camp Swift, but it is too early to know if any new colonies have been successfully started. It is usually the next spring before the incipient colony is large enough to be easily noticed. The first few months of a colony consist of the newly mated queen tending the first batch of brood using reserves from degenerating flight muscles as a nutrition source. There is no foraging until this first brood becomes adults around three months later. These results of mound counts in these plots are given as part of Table 5 and Table 6.

Pitfall traps collected more species than bait traps. When fire ants were present, they tended to exclude other ants from the bait traps, so bait traps can be utilized best to evaluate relative numbers of fire ants present. Pitfall traps give a better picture of the diversity, because they are a more random collecting method, collecting anything that falls into them. Results at Camp Swift are given in Table 1. The spring collection was a time when ants were very active and probably represents a more realistic picture of the ant diversity. The fall samples were collected after a severe drought and record temperature period had occurred, probably yielding unrealistically low levels of ant activity.

Table 1. Ant totals collected in traps at the treatment and control sites at Camp Swift. The numbers provided are totals from 9 pitfall traps and 9 bait traps. Note that conditions were very dry in the fall 2000 collection and comparisons are not realistic between spring and fall.

Camp Bowie. Camp Bowie has many Pogonomyrmex barbatus sites throughout the base and P. cornutum sightings are rare, but not unusual. There was no effort made to evaluate numbers of P. cornutum, but personnel at the base reported sightings. Camp Bowie is unique among the four facilities used for these tests because fire ants are not prevalent throughout the base. In fact, fire ants were found in only three regions, around the headquarters, buildings and firing ranges; around a pond and wooded area centered at N 31°38.494', W 98° 56.299'; and one S. invicta mound was sited at on open field, N31° 38.596', W 98° 56.438'. The rest of the base had no S. invicta activity observed. The second site (around the pond) had no native ants observed.

Pogonomyrmex barbatus colonies were surveyed at several sites in May 2000. The site at N31° 38.596', W 98° 56.438' had about 3 colonies per hectare of P. barbatus and many mounds of Linepithema sp. and Forelius sp. The site on the firing range had numerous harvester ants and will be reported upon below, as it was the test site for this program. A site at N 31° 36.895', W 98° 55.472' had about 10 colonies of P. barbatus per hectare and several other native ant mounds, but no S. invicta mounds. This concentration of P. barbatus is quite high for a harvester ant with large colonies. Harvester ants were also observed at several other areas throughout the base.

Harvester ant populations at the treatment site have remained stable throughout the test. In fall 1998, there were 3 P. barbatus colonies within the treatment site and those colonies have remained throughout the test. The control site had one P. barbatus colony, which is also still present in 2000. Solenopsis invicta colonies fluctuated as reported in Table 6. The survey of ant species at Camp Bowie is given in Table 2. The site used for this project has had relatively high densities of fire ants for many years (Jim Hillegus personal communication). This site did not have a large biodiversity of ant species collected in the traps.

Table 2. Ant totals collected in traps at the treatment and control sites at Camp Bowie. The numbers provided are totals from 9 pitfall traps and 9 bait traps. Note that conditions were very dry in the fall 2000 collection and comparisons are not realistic between spring and fall.

Ft. Wolters. Harvester ants at Ft. Wolters are all Pogonomyrmex barbatus and are found in densities less than occur at Camp Bowie or Camp Swift. Throughout the base the highest P. barbatus densities were about 5 per hectare (which is still considered a high density for this species). Pogonomyrmex barbatus was found in five distinct regions of Ft. Wolters. One of the locations does not have a recorded GPS location, but was found near the firing ranges. Other locations of P. barbatus were N 32° 50.964', W 98° 02.525' ( 2 colonies or P. barbatus and about 20 colonies of S. invicta per hectare; N 32° 51.019', W 98° 02.652' (1 colony of P. barbatus and about 40 colonies of S. invicta per hectare); N 32° 52.122'm W 98° 02.479' (5 colonies of P. barbatus and about 10 colonies of S. invicta per hectare; and N 32° 51.405', W 98° 01.874' (1 colony of P. barbatus and about 40 colonies of S. invicta per hectare). These numbers will support P. cornutum populations and there have been several sightings at Ft. Wolters (Sgt. York personal communication).

The bait test at Ft. Wolters showed a decrease in fire ant colonies from 54 colonies to 12 colonies in the first year of the project. In spring 2000, S. invicta colonies had increased to 26 colonies and again reduced to 6 in late summer 2000 (however this last figure may be an underestimate due to extreme weather conditions). The control site ranged around 40 colonies, except for the final summer survey of 14 mounds. The number of P. barbatus colonies in the treatment plot has remained at two throughout the test. In the control plot, P. barbatus started with one colony, which was lost in the summer of 2000. Results of the prescription bait treatment program are given in Tables 5 and 6. Ant surveys collected at baits and in pitfall traps are shown in Table 3.

Overall summary
The prescription bait treatment program has the cumulative results listed in Table 4. These results are provided to survey the effectiveness of the protocol. Solenopsis invicta was reduced by prescription treatments by an average of 92 percent from spring, 1999 to fall, 2000; although this result may partially be a result of weather. A more accurate approximation of the reduction would be somewhere between a 58 and 92 percent reduction. In these same treatment plots about 6 percent of the harvester ant mounds were lost. In untreated control plots fire ant levels changed in concentration somewhere between declining by 58% to increasing by 9 percent. In control plots, about 67 percent (an average of the sites) of harvester ant colonies were lost when insecticide treatment was not provided. Since many more harvester ants were found at one site (Camp Swift) in control plots the actual percent lost was about 88 percent of all Pogonomyrmex species in the non-treated plots.

Table 3. Ant totals collected in traps at the treatment and control sites at Ft. Wolters.

Table 4. Percent change in mound densities between treatment and untreated control plots. Solenopsis invicta and combined Pogonomyrmex species were evaluated from spring 1999 to fall, 2000. Results for S. invicta may be skewed downward because of dry conditions making it difficult to identify mounds. Therefore, columns with "*" are determined from spring 1999 to spring 2000, just prior to the spring treatment. Results for the Pogonomyrmex sp. should be accurate because even in the extreme weather conditions, these ants were active and colonies could be accurately identified.

Table 5. Number of harvester ants in plots at three Texas National Guard facilities. Camp Swift results include both Pogonomyrmex barbatus and P. comanche. Camp Maxey is not included because there are no remaining harvester ants.

Table 6. Number of Solenopsis invicta mounds in plots at three Texas National Guard facilities. Camp Maxey is not included because there are no remaining harvester ants for continuation of the project.

Discussion
Some of the results for 2000 are rather misleading because of the severe drought and high temperatures of late summer and early fall. It is unfortunate that the timing of this report was such that it is hard to make sense of the fire ant numbers. However, it is clear that there has been a decline in S. invicta numbers from spring 1999 to fall 1999, and even though there was naturally some rebound in colony number before the spring 2000 treatment, these numbers were lower than spring 1999. Actual numbers of S. invicta colonies will likely be even much different between treatment and untreated control sites, when the weather conditions make it easier to count colonies. The observed fall 2000 numbers are almost certainly more than are reported, but mounds were simply not apparent on the surface. This is also demonstrated in the numbers of S. invicta colonies appearing to reduce by over 50 percent in the untreated control colonies. In reality, these numbers are probably very close to the spring mound counts.

The results that are encouraging are those of harvester ant conservation. There has been a loss of three Pogonomyrmex barbatus colonies at Camp Swift during the treatment time, but 94 percent of all Pogonomyrmex colonies have been conserved. This loss may be a natural fluctuation, or it could be a result of the remaining fire ants within the plot. However, mating flights were observed this year and if any of these were successful, they should be apparent by later this fall, or certainly by spring 2001. If some of these are able to establish it may be because predation and competition by fire ants are becoming less in the treatment plots.

One outcome of this project that has already been demonstrated is that broadcast bait treatments are detrimental to harvester ants, and probably to other native ants also. At Camp Maxey, the only harvester ants were associated with disturbed areas on the firing ranges. These areas were part of another program to treat fire ants along these ranges using less labor intensive broadcast baiting. The harvester ants at these areas were eliminated, along with many fire ants. However, the results are that fire ants return (although at lower numbers if the bait application is regularly applied), but harvester ants do not. Other native ant species are probably not found in these treatment areas after the two years of broadcast baitings. The result is that these treatments must be continued or fire ants will soon be found in numbers even larger than before the start of the program because there is no longer competition from other ant species.

Surveys of other ants in both the prescription bait treatment plots and their associated control plots do not really mean much at this time. They do show that the treatment program does not appear to be affecting large numbers of native ants, but even this is hard to say at this time. These results were gathered to provide a good starting point for the evaluation of this program in regards to affects of the entire ant population. Because the fall results were skewed by weather conditions, comparisons are really meaningless. The biodiversity in these small plots is ample for good evaluations of this treatment program and its effects on native ants and will provide numbers needed for a good statistical analysis in next years program.

National Guard management policies do not have to be changed to maintain the work on this project and preservation of harvester ants and horned lizards. Harvester ants and horned lizards prefer disturbed habitats. Training exercises should not greatly affect the maintenance of these populations. However, other native species may be more adversely affected. Thus far, there is little information on the effects on other native ant species, but this information may be forthcoming in next years project. An important concern is the use of pesticides in these areas. Many native ants, such as harvester ants, are much more susceptible to insecticides than the red imported fire ant. Treatment strategies other than prescription bait treatments will almost certainly impact harvester ants and in turn, impact populations of the Texas horned lizard. As stated earlier, elimination of all ant species in an area makes it easier for re-establishment by red imported fire ants. To maintain native ants, the only insecticide use should be such that it is limited to the target population.

References Cited
Blackshear, S. D. and J. V. Richerson. 1999. Ant diet of the Texas horned lizard (Phrynosoma cornutum) from the Chihuahuan desert. Texas Journal of Science, 51: 147-152.

Cole, A. C. 1968. Pogonomyrmex Harvester Ants: A Study of the Genus in North America. The University of Tennessee Press, Knoxville, TN. 222 pp.

Contreras, C. and A. Labay. 1999. Rainbow trout kills induced by fire ant ingestion. Texas Journal of Science, 51: 60-61

Folgarait, P. J. 1998. Ant biodiversity and its relationship to ecosystem functioning: a review. Biodiversity and Conservation, 7:1211-1244.

Mann, C. C. 1994. Fire ants parlay their queens into a threat to biodiversity. Science, 263: 60-61.

Porter, S. D. and D. A. Savignano. 1990. Invasion of polygyne fire ants decimates native ants and disrupts arthropod community. Ecology, 71: 2095-2106.

Taber, S. W. 1998. The World of the Harvester Ants. Texas A&M University Press, College Station, TX. 213 pp.

Fire Ant Management on Pop-up Target Firing Ranges
Report on Contract No. TX98-E23-04 401-9-5504
May 31, 2000
Prepared by Dr. Michael Merchant, Associate Professor and Urban Entomologist
Texas Agricultural Extension Service

For Dr. Paul E. Powell, Training Site Environmental Specialist, Facilities & Engineering Directorate, Environmental Resources Management Branch, Adjutant General's Department, AGTX-EV, P.O. Box 5218, Austin, Texas 78763-5218; 512/465-5001 ext. 6035; FAX: 512/465-5141; ppowell@ pollution.org

Abstract.
Two granular insecticides were evaluated for the control of red imported fire ants, Solenopsis invicta, in soil surrounding pop-up targets on a Texas Army National Guard firing range in Mineral Wells, Texas. Both fipronil 0.1 G- and tefluthrin 1.5 G-treated plots had significantly fewer numbers of fire ant colonies compared to untreated controls. Numerically fewer foraging fire ants were also found in treated vs. untreated plots, though differences among treatments were not significant.

Prior to treatment, fire ants were observed causing damage to natural rubber and urethane foam components of the pop-up target lifters. Nearly 100 percent of electrical outlet weatherstripping and 22% of the rubber boots on pop-up targets were affected by fire ants.

Treatments were applied to evaluate the ability of a 1% fipronil formulation to protect rubber components from fire ant chewing damage. A 2 x 5 factorial experiment has been initiated to evaluate the long-term effectiveness of soil and component treatment to prevent fire ant damage. Continuation of the research is recommended to complete observations on the effectiveness of these treatments.

Background
The Texas Agricultural Extension Service was first contacted in May, 1998 for assistance in developing a management program for red imported fire ants on National Guard firing ranges. An evaluation of commercially available products was suggested based on earlier research work conducted on commercial, ground based electrical transformers. The project was approved as contract number an TX98-E23-04, and funds were awarded on September 1, 1998. Due to a delay in securing chemical company support, and availability of test materials, a request to extend the project completion date until May 31, 2000 was approved November 1, 1999. This study reports the results of this investigation.

Introduction
The red imported fire ant, Solenopsis invicta Buren, is a persistent pest of ground-based electrical equipment throughout the southern United States (MacKay et al., 1992., Slowik et al. 1997). Recently, several National Guard camps in Texas have reported problems with fire ants infesting and damaging firing range pop-up targets (Merchant, 1999). Camps Maxey (Lamar County, Texas) and Swift (Bastrop County, Texas) report 20 to 40 percent loss of functionality in electronic pop-up targets due to fire ant invasion. Costs of this damage are significant and have resulted in loss of equipment and economic loss. In 1998 the entire pistol range at Camp Bowie was shut down for rewiring, due to damage caused by fire ants in 100 percent of the target lifters. Estimated repair costs were $35,000 with additional costs incurred due to loss of the use of the ranges there (Paul Powell, personal communication, 1998).

Objectives of the study were to identify promising treatment combinations that might reduce the impact of fire ants on ground-mounted machinery, such as pop-up target lifters. Specifically we attempted to determine (1) whether soil insecticide treatments can reduce fire ant foraging and damage around target lifters for extended periods of time; (2) whether an easily-applied treatment can significantly prolong the effective life of the foam weatherproofing used in power outlets and the natural rubber boots used to seal the lifter mechanism.

Materials and Methods
Phase I. Granular site treatment. Fire ant activity was estimated around target lifter sites by counting all active fire ant mounds within an 8 ft ( 2.43 m) radius circle around each site (Figure 1). Mound size was estimated according to a modified rating system based on the work of Harlan et al. (1981). Colonies observed at the site were generally small and rated as 1 (less than 100 ants, mound less than 10 cm diameter), 2 (100 to 1,000 ants, and usually 10 to 40 cm diameter mound), or 3 (1,000 to 10,000 ants, mound usually greater than 40 cm diameter).

In addition to mound counts, assessments were made of foraging fire ant worker abundance on October 19, 1999 and May 31, 2000, respectively. Glass shell vials (1 dram capacity) were baited with two pellets of Seafood Purina® Tender Vittles® cat food, and placed on the soil adjacent to each pad site. After a 2 to 3 hr exposures, vials were collected, stoppered, transported to the laboratory, and frozen. Ants collected in the vials were later counted and identified to species.

Soil treatments were applied to lifter sites on October 19, 1999. Insecticide treatments were applied uniformly to the soil inside a 4.88 m (16 ft) square plot surrounding each lifter vault (Figure 2). Granular formulations of fipronil (Collins et al., 1999) and tefluthrin (Merchant 1998) were applied using a shaker made from a 620 ml (1.3 US pint) Rubbermaid® Servin' Saver bowl with 25 1/8-inch holes drilled in the lid. Soil treatments included:

I. fipronil 0.1 G (low rate) 50 lb product/A (122 g/plot or 0.05 lb a.i./A)
II. fipronil 0.1 G (high rate) 100 lb product/A (244 g/plot or 0.1 lb a.i./A)
III. tefluthrin 1.5 G (low rate) 66.7 lb product/A (161 g/plot or 1.0 lb a.i./A)
IV. tefluthrin 1.5 G (high rate) 133 lb product/A (322 g/plot or 2.0 lb a.i./A)
V. untreated control

Treatments were assigned to lifters according to a completely randomized design with 12 replications per treatment.

Phase II. Component treatment. The second phase of this research has not yet been completed. In Phase II the long-term effects of treatments on the integrity of rubber and foam lifter components (i.e., rubber boots used to seal the lifter armature of targets, and weatherproof seals used on outlet covers) will be evaluated. This portion of the research was begun on 28 March, 2000 when all the old rubber boots were replaced with new boots ordered through the National Guard supply system. In June 2000 a 1 percent suspension of fipronil 10.2% SC in mineral oil will be applied to half of the rubber boots on the test site. In addition, all existing outlet covers will be replaced to allow ongoing assessment of fire ant damage to foam or neoprene weatherproofing on the treated portions of the range.

The impact of treatments on the integrity of foam and rubber components of the target lifters will be evaluated by (1) counting the number of fire ant produced holes in rubber boots, (2) rating the quality and presence or absence of tunneling in foam inserts on power outlets; and (3) monitoring dirt and debris in power outlets. In addition I will evaluate the effects of treatments on cracking or other deterioration of rubber boot and foam inserts.

The experimental design to measure the effects of treatments in protecting rubber and foam components of the lifters will be a 2 x 5 factorial, with treatments randomly assigned to the lifters. A total of 60 lifters is being used with six replicates of each treatment.

Results
Numbers and sizes of fire ant mounds at the Fort Wolters combat pistol range, around target lifter sites, were recorded on April 20, 1999, prior to any treatments being made. Based on this sample, spring fire ant mound density was estimated at approximately 576 mounds per acre, based on an average of 2.37 (± 0.23 SEM) mounds per plot (179 ft²).

In addition, on this date all target lifters were observed for damage to rubber boot seals on lifter armatures and to weatherproofing used on electrical outlets. Approximately 22 percent of the natural rubber boots used to seal the lifter armature exhibited what appeared to be fire ant chewing damage, with 1 to 3 holes per boot (Figure 3). On September 19, 1999, a cloudy day, fire ants were observed clustered on the accordion ridges and edges of about 8 percent (n=84) of the rubber boots, apparently chewing on the rubber.

Ant activity and damage was also evident around the plugs and electrical outlets supplying power to each target lifter. Soil and debris was found in 50 percent of the outlets, and dead ants were found in 38.6% of outlets (n=44). Nearly 100% of the urethane foam electrical outlet cover weatherproofing was damaged by what appeared to be similar fire ant chewing behavior (Figure 4), although ants were not observed damaging foam inserts.

The reason for fire ant attraction to natural rubber or urethane foam is unclear. Similar observations of fire ant chewing on insulation of non-electrified copper wiring have been made by other researchers. Texture of the boots, or oils found in natural rubber, might act as stimulants of fire ant chewing behavior (S.B. Vinson, personal communication).

Because of dry weather during the fall and winter of 1999-2000, mound counts were not attempted until 28 March and 25 May 2000, five and eight months after treatment (MAT), respectively. Mound counts from both sample dates were totaled for the following analysis, although most of the colonies observed and marked on 28 March were not active during the May sample three months later.

There was a significant difference in mound counts between treated and untreated plots when the five and eight MAT mound counts were combined (ANOVA, F=3.88, d.f.=4,55; P<0.0001) (Table 1). Untreated plots had significantly more active fire ant mound activity by eight months after treatment.

Table 1. Effect of various treatmens on numbers of active red imported fire ant colonies around firing range target lifters. Combined mound counts between five and eight months after treatment. Fort Wolters Army National Guard Base, Mineral Wells, Texas. March to May, 2000.

* Numbers within the column followed by the same letter are not significantly different (ANOVA, F=3.88, d.f.=4,55; P<0.0001)

There were significantly fewer fire ant foragers present in vials following a two hour exposure on June 1, 2000 (8 MAT), compared to numbers collected on Oct. 19, 1999, prior to treatment of the test area. Lower numbers of foragers may have been due to seasonal or temperature differences, or due to treatment effects. There were numerically fewer fire ant foragers in treated vs. untreated plots on June 1, 2000, however the differences were not significant (ANOVA, F=0.42, d.f.=4, 55; P>0.796) (Table 2).

Table 2. Effect of various treatments on numbers of foraging red imported fire ants collected in baited glass vials next to firing range target lifters. Fort Wolters Army National Guard Base, Mineral Wells, Texas. March to May, 2000.

Discussion
Fire ant mounds were very common on the combat pistol range at Fort Wolters Army National Guard Base. The pre-treatment estimate of 576 mounds per acre indicates a high population density, and suggests that the area is infested with the multiple queen (pylygynous) form of the red imported fire ant. Although we did not document any failures of lifter units in this study, the effects of fire ant damage on rubber and foam components of the ground-based equipment were apparent.

Fire ant mounds were significantly less common in treated vs. untreated plots at eight months after treatment. However, the number of active mounds were very low in control plots throughout the post-treatment evaluation, possibly due to inter-plot effects or the effects of drought and cooler weather on local fire ant populations. No significant differences among the insecticide treatments were detected by eight months after treatment. Counts of foraging adult ants are generally not highly reliable as indicators of colony density; however, there was a trend for fewer foraging ants to be found in treated lifter plots.

Although results are promising for use of both tefluthrin and fipronil granular insecticides as protectants for firing range equipment, additional time is needed to evaluate the long-term effectiveness of these treatments. In addition, an extended delay in obtaining new rubber boots for all lifters has meant that no data is yet available on the effectiveness of treating rubber boots with 1% fipronil.

A continuation of the project is recommended to allow time to evaluate the long-term effects of these treatments. A two to three year continuation of the project would allow time for fire ant re-infestation of treated and untreated plots, and would permit observations of the potential for fire ants to damage foam and rubber components of the lifter sites.

Literature Cited
Collins, H., A.-M. Callcott, et al. (1999). Evaluation of candidate quarantine treatments for control of IFA in commercial grass sod. U.S. Department of Agriculture/APHIS. Unpublished report, Proj. No. FA01G066. Gulfport, MS.

Harlan, D. P., W. A. Banks, et al. (1981). Large area tests of AC-217,300 bait for control of imported fire ants (Hymenoptera: Formicidae) in Alabama, Louisiana, and Texas. Southwestern Entomologist 6(2): 150-157.

MacKay, W. P., S. Majdi, et al. (1992). Attraction of ants (Hymenoptera: Formicidae) to electric fields. Journal of the Kansas Entomological Society 65(1): 39-43.

Merchant, M. E. (1998). Insecticides for control of red imported fire ants in pad-mounted electrical transformers. Final Report. Unpublished report Texas Agricultural Extension Service, Dallas. May 18, 1998.

Merchant, M. E. (1999). Fire Ant Management on Pop-up Target Firing Ranges. Proposed Research Protocol. Submitted to Paul Powell, October 15, 1999. 3 pp.

Slowik, T. J., H. G. Thorvilson, et al. (1997). Response of the red imported fire ant to magnetic fields in the nest environment. Southwestern Entomologist 22(3): 301-306.

Figure 1. Schematic diagram of firing range target vault showing sampling and treatment zones. Subtracting the area of the target lifter vault (22 ft²) from the overall area of the treated zone (256 ft²) gave a total treatment area of 234 ft².

Figure 2. Plot surrounding pop-up target marked for evaluation of mound densities (left), and close up view of pop-up target lifter showing outlets and ground-based lifter unit. Fort Wolters Army National Guard Base, Mineral Wells, Texas. Summer, 1999.

Figure 3. Fire ant chewing damage to rubber boot used to seal the lifter armature on pop-up targets. Holes in boots were judged to be fire ant chewing damage if they were (1) not associated with obvious cracking or weathering, (2) oval to moon-shaped, and (3) having rounded edges. Fort Wolters Army National Guard Base, Mineral Wells, Texas. 1999.

Figure 4. Urethane foam weatherproofing taken from electrical outlet covers used in pop-up targets at Fort Wolters combat pistol range. Damage to foam presumed due to tunneling behavior by the red imported fire ant, Solenopsis invicta (image approximately life-size).

Management Practices for Red Imported Fire Ant Populations on
Texas Army National Guard Grounds
Final Report- October 2, 2000

Rody L. Best, Extension Assistant- Fire Ant Project, TAEX
Charles L. Barr, Extension Program Specialist-Fire Ant Project, TAEX

Camp Swift, Camp Bowie, Fort Wolters and other training camps in the eastern two-thirds of Texas are infested with the red imported fire ant, Solenopsis invicta Buren. At each training camp, there exists a series of firing ranges: a Pistol Range; an M-16 Range; an M-60 Range; and, a Known Distance Range (KDR). Red imported fire ants from mounds near the foxholes and sandbags endanger troops during practice, stinging some individuals and causing potential medical problems.

This project is an ongoing trial that was first initiated in the fall of 1998 by Dr. Jerry Cook, an entomologist now at Sam Houston State. It is designed to determine the best management practices for controlling the red imported fire ant by evaluating the application of commercially available fire ant baits on Texas Army National Guard firing ranges. An Integrated Pest Management (IPM) program has been designed that will allow the Texas Army National Guard to meet their goal of reducing pesticide use and allow managers to select specific products best suited to these efforts.

Materials and Methods
Three sites were chosen to conduct the evaluations: Camp Swift, Camp Bowie, and Fort Wolters. These sites differed in both climates and red imported fire ant densities. Two commercially available baits were chosen: Extinguish™ (active ingredient- 0.50% (s)-methoprene) and Amdro® (active ingredient- 0.73% hydramethylnon). At each training camp, a series of firing ranges were evaluated for red imported fire ant infestation: a Pistol Range, an M-16 Range, an M-60 Range, and a Known Distance Range. The timing of the treatments was determined by the level of infestation and climatic conditions. Due to a severe lack of rainfall in the fall of 1999 and a lack of visible fire ant mounds, treatments were not initiated until the spring of 2000.

Camp Swift. The firing ranges at Camp Swift were evaluated for red imported fire ant infestation on Feb. 28, 2000. Only one range- the Known Distance Range (KDR) had a sufficient number of mounds to conduct a replicated test. Test plots were established on the 100-yard firing line so that the total treatment plot area was approximately 36 by 408 ft. There were 40 firing stations; each designated with sandbags and a numbered steel plate. Each of the four treatment plots was composed of 10 firing stations, approximately 102 by 36 ft. An untreated control plot was established on the 200-yard firing line and was approximately the same size.

An initial count was conducted to determine the number of active red imported fire ant mounds (Table 1) in the treatment plots and control plot. Mounds were determined active if a defined number of fire ants rose to the surface after light disturbance. A treatment of Amdro® (0.73% hydramethylnon) was then applied to the plots at rate of 1.5 lbs per acre using a Cyclone 1C1 hand-held seeder. Post-treatment evaluations were conducted at 8, 16, and 24 weeks.

The cantonement area was also evaluated for red imported fire ant infestation on Feb. 28, 2000, and found to be heavily infested - especially next to the buildings. An initial count was conducted to determine the number of active red imported fire ant mounds that were in contact with the base of the buildings (Table 2). A hopper blend (1:1 ratio) of Amdro® (0.73% hydramethylnon) and Extinguish™ (0.50% (s)-methoprene) was applied around the cantonement area at a total rate of 1.5 pounds per acre (0.75 lb Amdro and 0.75 lb Extinguish). Post-counts of mounds in contact with the buildings were conducted at 8, 16, and 24 weeks post-treatment.

Camp Bowie. The firing ranges at Camp Bowie were evaluated for red imported fire ant infestation on April 14, 2000 and the Pistol Range was determined to have a sufficient number of mounds to conduct a replicated test. The test plots were established on the firing line for a total treatment plot size of approximately 250 by 12 ft. There were 16 firing stations; each designated with a wooden post. Three treatment plots were established - each approximately 60 by 12 ft. The control plot was located on the south side of the Pistol Range and was approximately the same size.

An initial count was conducted to determine the number of active red imported fire ant mounds (Table 3) in the treatment plots and control plot. Mounds were determined active if a sufficient number of fire ants rose to the surface after light disturbance. A hopper blend (1:1 ratio) of Amdro® and Extinguish™ was then applied to the plots at a total rate of 1.5 lbs per acre (0.75 lb Amdro and 0.75 lb Extinguish). Post-counts were then conducted at 8 and 16 weeks post-treatment.

The cantonement area was also evaluated for red imported fire ant infestation on April 14, 2000 and was moderately infested. A hopper blend (1:1 ratio) of Amdro® and Extinguish™ was applied around the cantonement area as described above.

Fort Wolters. The firing ranges at Fort Walters were evaluated for red imported fire ant infestation and the M-16 Bravo Range was determined to have a sufficient number of mounds to conduct a replicated test. There were 40 firing stations; each designated with sandbags and a numbered steel plate. The treatment plot was established on the firing line for a total treatment plot size of approximately 412 by 12 ft. An untreated control plot was located near the Combat Pistol Range and was approximately 45 by 40 ft.

An initial assessment was conducted to determine the number of active red imported fire ant mounds (Table 4) in the treatment plots and control plot. Mounds were determined active if a sufficient number of fire ants rose to the surface after light disturbance. A hopper blend (1:1 ratio) of Amdro® and Extinguish™ was then applied as described for Camp Bowie. Post-treatment assessments were made after 8 weeks. The cantonement area was evaluated for red imported fire ant infestation and was moderately infested. It was also treated with the hopper blend.

Results
Camp Swift. At 24 weeks post-treatment, the application of Amdro® had reduced active mound numbers by 68 percent (100% percent control in two of the plots). The mound counts in the untreated plot dropped almost 43 percent (Table 1). Control of red imported fire ant mounds near buildings within the cantonement area was very successful. The average reduction around 20 buildings was approximately 94 percent (Table 2).

Table 1. Number of active red imported fire ant mounds- Known Distance Range.

Table 2. Number of active red imported fire ant mounds in contact with buildings in the cantonement area.

Camp Bowie. The number of red imported fire ant mounds on the Pistol Range at Camp Bowie were reduced an average of approximately 84 percent 16 weeks after treatment with a hopper blend of Amdro® and Extinguish™. The untreated plots dropped 37.5 percent (Table 3)

Fort Wolters. Eight weeks after treatment, the number of red imported fire ant mounds on the M-16 Bravo Range at Fort Wolters was reduced by approximately 90 percent. The untreated plots dropped over 83 percent due to extreme high temperatures and a lack of precipitation (Table 4).

Discussion
The project was initiated in the fall of 1999, but due to a lack of rainfall, which prevented fire ant mound building activity, the treatments were delayed until the spring of 2000. The density of red imported fire ant mounds varied between firing ranges within each camp also, due to the geographic variations of the soil and vegetation, climatic conditions, and due in some part to treatments applied the previous year by Dr. Jerry Cook.

Data taken from the Known Distance Range at Camp Swift (Table 1) shows plot number 4 having a much higher mound density when compared to plots 1, 2, and 3. This is because targets 30 to 40 (which comprised plot 4) were not often used. This resulted in less traffic on plot 4, which allowed for less compacted soil, more moisture and more vegetation. These conditions provided a more suitable habitat for red imported fire ants and thus, yielded higher mound densities compared to other plots after treatment, probably as a result of re-infestation. By treating plot 4 as an outlier, mound reduction is nearly 87 percent, as compared to 68 percent when plot 4 is included. This leads to an important consideration for managers when treating areas with high re-infestation pressure- treating larger areas can reduce the opportunity for re-infestation by reducing the re-invasion pressure on the outside of the treatment area.

Hopper blend treatments around the cantonement areas were also successful in reducing mound densities, providing a 94 percent reduction in mounds in contact with buildings at Camp Swift (Table 2). However, one exception was building 252. While the number of fire ant mounds in contact with building 252 were eventually reduced; the data reveals an unusually slow rate of reduction. The data shows a sharp reduction in mound numbers between 16 and 24 weeks post-treatment, which is a characteristic of the slow effects of the active ingredient (s)-methoprene in the insect growth regulator, Extinguish™ (typically 3 to 6 months). Observations notes taken in the field at 8 and 16 weeks reveal that the effects of an insect growth regulator were apparent- lack of brood coupled with an abundance of large workers and reproductive alates. From this information, it is believed that an uneven mixing of the baits, Amdro® and Extinguish occurred, which would have led to an uneven ratio of bait being applied. With only a small amount of Amdro being applied, the effects of Extinguish took several months to begin working. The data from the cantonement area points out an important thing to remember when using the hopper blend treatment - when properly applied, the hopper blend treatment can provide the manager with both the rapid control characteristics of Amdro and the long term suppression characteristics of Extinguish.

The hopper blend of Amdro® and Extinguish™ at a rate of 1.5 lbs per acre proved to be an effective treatment in reducing fire ant mound numbers on Texas Army National Guard firing ranges. Mound densities at the three bases were reduced by an average of 81percent (Table 5). While the hopper blend treatments were successful in reducing the fire ant densities, the lack of rainfall and extreme heat across the state also contributed to this decline as is evident by the dramatic decline of the untreated plots (especially Fort Wolters, Table 4).

Table 5. Total percent reduction of active red imported fire ant mounds using a hopper blend of Amdro® and Extinguish™ at a rate of 1.5 lbs per acre, calculated per acre.

Temperature and precipitation extremes like those experienced over the summer of 2000 force red imported fire ants to significantly reduce their activity. Foraging primarily occurs during the cooler temperatures of the night and with a lack of available water and the reduction in foraging activity, fewer resources are available for the colony. The colony produces less brood, saving their limited resources for better conditions. Mound building is reduced to a minimum while the fire ants burrow deep into cooler soil. When conditions become favorable again, fire ants resume normal activities.

These adverse weather conditions also play a role in determining the optimum conditions for applying baits. Since temperature and precipitation extremes reduce foraging activity by red imported fire ants, the success of bait applications can be affected. The best method to determine if fire ants are foraging is to put out a small pile of bait and monitor it for 15 minutes to one hour. If a sufficient number of ants are recruited to the bait pile, then conditions are favorable for a bait application. Optimum foraging by red imported fire ants usually occurs when the soil is moist, and the temperature is between 65 and 90 degrees Fahrenheit under sunny skies. Baits should not be applied if precipitation is expected within 24 hours of treatment or the bait may be ruined. If conditions are not favorable for a bait application, then treatment should be delayed.

While bait applications can be made any time of the year that conditions are favorable, the Texas Extension Service promotes the application of baits in the fall months, typically September and October. Bait applications in the fall are advantageous for several reasons. Baits take several weeks to months before the effects become evident. Applying bait in the fall reduces the chance of problem encounters with fire ant mounds because both people and the ants are not as active outside as they would be in spring months. By the time spring arrives, ant populations should be suppressed. This is not to say that bait must only be applied in the fall. In the event that conditions do not permit a fall treatment, as was the case for this project, a spring treatment is recommended (typically between the months of March and May), so long as conditions are favorable. While the effects of a spring treatment still take weeks to become evident, maximum suppression can be achieved by summer.

About two percent of the human population can react to stings enough to need medical attention, with a smaller percentage having life-threatening reactions. Red imported fire ants are a serious health risk because they endanger troops near foxholes and sandbags. The benefit of using a broadcast treatment for fire ants is the ability to treat large areas with a minimal amount of pesticide and labor while reducing health risks. It is essential that the management program be on-going and that mound densities are monitored and follow-up treatments are applied. Continuation of the Integrated Pest Management program will allow the Texas Army National Guard to meet their goal of reducing pesticide use and provide managers with information on selecting specific products best suited to these efforts.

	Pre- Nov. 15	5 days Nov. 20	11 days Nov. 26	19 days Dec. 4	35 days Dec. 20	51 days Jan.5, 2001
	Pre- Nov. 15	5 days Nov. 20	11 days Nov. 26	19 days Dec. 4	35 days Dec. 20	51 days Jan.5, 2001
Field removal	6	5.3	3.5	3.0	3.8	3.3
"New" mounds	0	1.3	4.3	5.3	7.5	4.8
Total	6	6.6	7.8	8.3	11.3	8.1

Untreated	6	5.8	5.3	5.3	5.0	4.5
"New" mounds	0	1.3	2.3	4.5	5.3	3.8
Total	6	7.1	7.3	9.8	10.3	8.3

Percent "Control"
Treated mounds	---	8.6%	34.0%	43.4%	24.0%	26.7%
"New mounds"	---	0.0	-46.5	-15.1	-13.3	-20.8
Total	---	14.1	-12.8	10.2	-8.8	12.0

Treatment	Nov. 15 (0 days)	Date Nov. 16, 17, 20, 22, 26, Dec. 4 (1, 2, 5, 7,11,19 days)
Malt-O-Meal	1,1,1,1	1,1,1,1
Instant grits	1,1,1,1	1,1,1,1
Untreated	1,1,1,1	1,1,1,1

Treatment	Ingredients	Dose Level	LD50
Untreated	Water	1 gallon	NA
Gardenville Fire Ant Killer (Note: this product is not an EPA registered insecticide)	30% orange oil, 70% manure compost tea	6oz/gallon	>5000 mg/kg
Orthene® dust (50 WP)	acephate + inert ingredients	2 teaspoons	980 mg/kg
Organic Solutions Fire Ant Killer	0.1% pyrethrins + 1% piperonyl butoxide (PBO)+ 85% diatomaceous earth (DE) + inert ingredients	4TB/gallon	>5000 mg/kg
Organic Resources Multipurpose Fire Ant Killer I	0.2% pyrethrins + 1% PBO + 85% DE + surfactant + inert ingredients	4TB/gallon	>5000 mg/kg
Organic Resources Multipurpose Fire Ant Killer II	0.2% allethrin + 1% PBO + 85% DE + surfactant + inert ingredients	4TB/gallon	>5000 mg/kg
Diatect Results	0.2% pyrethrins + 85% DE + inert ingredients	4TB/gallon	>5000 mg/kg

Treatment	24 hr	Satellites	48 hr	Satellites	1 Week	Satellites	4 Weeks	Satellites
Water Only 1 gal	10	0	10	0	10	0	5*	0
Gardenville 6oz/gallon 1 gal/mound	6	3	0	2	0	1	0	1
Orthene® dust 2tsp/mound	1	0	1	0	0	0	0	0
Organic Solutions 1 gal solution/mound	4	2	1	4	0	0	0	0
Organic Resources I 1 gal solution/mound	2	2	1	1	0	1	0	0
Organic Resources II 1 gal solution/mound	1	0	0	1	0	1	0	0
Diatect Results 1 gal solution/mound	5	2	2	2	0	2	0	0

TREATMENT	NUMBER OF ACTIVE MOUNDS & % OF CONTROL ON
TREATMENT	Pre Treatment on 4/27	6/1 - 5 Weeks	7/8 - 10 Weeks
Spectracide®	10*	3 (70%)	0 (100%)
Amdro®	10	3 (70%)	2 (80%)
Untreated	10	10	10

BROADCAST METHOD	INDIVIDUAL MOUND TREATMENT
Product	Cost/ Lb	Total Amt Used / Cost	Cost Per Mound*	Amt Per Mound/Total	Total Product Cost/ Per Mound Cost
Amdro®	$8.50	3 oz / $1.70	$ 0.17	2 ½ oz / 1.56 lb	$13.30 / $1.33
Spectracide®	$7.49	1 lb / $7.49	$ 0.75	2 oz / 1.25 lb	$ 9.40 / $0.94

Test	Dates	Location	Site and Test Characteristics	Participants
#1	11/9/98 - 12/7/98	Taylor	Cool weather; heavy, calcareous, black clay soil; excess moisture	Mott, Barr, Best, Lennon
#2	7/30/99 - 8/27/99	Navasota	Very hot weather; clay loam soil; moist changing to very dry	Barr, Best
#3	3/20/00 - 4/17/00	D/FW	Warm weather; heavy, calcareous, black, clay soil; adequate moisture	Russell, Merchant
#4	3/31/00 - 5/3/00	Bryan	Warm weather; sandy soil over claypan; adequate moisture	Barr, Best
#5	5/24/00 - 6/21/00	Burleson County	Warm weather, bottomland silty loam soil; adequate moisture	Barr, Begnaud

Treatment	1 week treated	1 week new	1 week total	1 month treated	1 month new	1 month total
untreated	9.00 a	2.50 a	11.50 a	5.25 a	2.50 a	7.75 a
TB131-1 ½ oz	7.50 a	3.00 a	10.50 a	5.75 a	2.50 a	8.25 a
TB131-1 ¼ oz	9.25 a	2.25 a	11.50 a	5.25 a	1.75 a	7.00 a
Orthene	1.25 b	4.00 a	5.25 a	1.50 b	3.75 a	5.25 a

F	40.85	0.26	3.08	8.79	0.93	1.09
P	0.0001	0.8514	0.0682	0.0023	0.4563	0.3925
R2	0.9108	0.06146	0.4352	0.6872	0.1886	0.2134
MSD*	2.4616	6.3486	7.1639	2.7935	3.6107	5.2917

Treatment	day 3 treated	1 week treated	1 week new	1 week total	2 weeks treated	1 month treated	1 month new	1 month total
untreated	8.25 a	8.25 a	1.25 a	9.50 a	8.00 a	8.25 a	1.00 a	9.25 a
TB131-1 ½ oz x 1	7.25 a	6.75 a	0.50 a	7.25 a	5.00 a	4.25 b	0.75 a	5.00 b
TB131-1 ½ oz. x 2	8.00 a	8.50 a	1.00 a	9.50 a	6.50 a	5.50 b	1.25 a	6.75 ab
Org. Res.	0.00 b	0.00 b	1.00 a	1.00 b	0.00 b	0.00 c	0.50 a	0.50 c

F	27.09	31.22	0.49	18.12	14.12	30.59	0.48	29.02
P	0.0001	0.0001	0.6975	0.0001	0.0003	0.0001	0.7047	0.0001
R2	0.8713	0.8864	0.1086	0.8192	0.7793	0.8844	0.1638	0.8787
MSD*	3.1779	2.9996	1.8922	3.9623	3.8803	2.6065	1.9637	2.8745

Treatment	1 week treated	2 week treated	2 week new	2 week total	1 month treated	1 month new	1 month total
untreated	8.50 a	7.00 a	0.75 a	7.75 a	5.50 a	1.25 a	6.75 a
TB131-1 ½ oz x 1	8.00 ab	6.75 ab	0.25 a	7.00 a	5.25 a	1.50 a	6.75 a
TB131-1 ½ oz. x 2	7.75 ab	7.25 a	1.00 a	8.25 ab	5.25 a	1.00 a	6.25 a
Amdro®	4.25 b	3.00 b	0.50 a	3.50 b	2.25 a	0.50 a	2.75 a

F	4.26	4.46	0.77	6.80	2.78	0.81	3.81
P	0.0289	0.0252	0.5330	0.0063	0.0866	0.5105	0.0396
R2	0.5157	0.5272	0.1613	0.6296	0.4102	0.1691	0.4877
MSD*	3.9507	3.9969	1.5450	3.4548	3.8921	1.9869	4.1546

Treatment	1 month, of 10 treated	1 month new	1 month total
untreated	6.250 a	2.625 a	8.875 a
TB131-1, ½ oz x 1	5.125 a	2.375 a	7.750 a
TB131-1, ½ oz. x 2	4.938 a	2.813 a	7.500 a

F	3.61	5.48	4.06
P	0.0083	0.0006	0.0043
R2	0.30065	0.3950	0.3259
MSD*	1.6508	1.7173	2.0816

Number of active fire ant mounds/5 (4 replicates) (Percent Control in parentheses)
	Day Following Treatment
Treatment	Pre- June 21	2-days June 23	7-day June 28	14-days July 5	30-days July 21
Treatment	Pre- June 21	2-days June 23	7-day June 28	14-days July 5	30-days July 21
Untreated control	5.0	5.0	4.3	4.0	2.5 (1 new)
acephate, 50% dust* (Orthene®)	5.0	0.3 (94%)	0.3 (2 new) (93%)	0.3 (99%)	0.0 (100%)
deltamethrin 0.05%** Bengal® UltraDust® Fire Ant Killer	5.0	2.8 (44%)	2.5 (1 new) (42%)	2.0 (2 new) (50%)	1.5 (3 new) (40%)

Treatment	2 days	7 days	14 days	30 days
Untreated	5.00 a	4.25 a	4.00 a	2.50 a
acephate	0.25 c	0.25 c	0.25 c	0.00 b
deltamethrin	3.00 b	2.50 b	2.75 b	1.50 ab

F	74.45	22.27	37.50	5.70
prob.	0.0001	0.0003	0.0001	0.0252
R2	0.9430	0.8319	0.8929	0.5588
min. sig. diff.	1.0913	1.6778	1.2312	2.081

		Number Active Mounds in 6 Mound sample
Treatment/ ingredient	Rate (oz product per mound)	Pretreatment1	7 DAT	15 DAT	30 DAT
Amdro® (hydramethylnon)	2.5	6	0	0	0
Clinch® (abamectin)	2.5	6	3*	0	0
Eliminator® (spinosad)	2.5	6	2	0	0
Untreated	6	6	6	6	1

		Activity Index in 6 Mound sample
Treatment/ ingredient	Rate (oz product per mound)	Pretreatment*	7 DAT	15 DAT	30 DAT
Amdro® (hydramethylnon)	2.5	3	0	0	0
Clinch® (abamectin)	2.5	3	0.5	0	0
Eliminator® (spinosad)	2.5	3	0.2	0	0
Untreated	NA	3	3	3	3

Treatment	day 3 treated	1 week treated	1 week new	1 week total	2 weeks treated	1 month treated	1 month new	1 month total
untreated	8.75 ab	8.50 a	3.00 a	11.50 ab	8.75 a	8.25 a	3.00 a	11.25 a
TB131-1 ½ oz x 1	10.00 a	9.75 a	5.25 a	15.00 a	7.75 a	6.75 a	3.25 a	10.00 a
TB131-1 ½ oz. x 2	9.75 ab	7.50 a	4.75 a	12.25 ab	5.75 ab	4.75 ab	5.00 a	9.75 ab
Amdro®	7.50 b	6.00 b	2.00 a	8.00 b	3.00 b	2.00 b	1.75 a	3.75 b

F	4.28	2.38	1.32	4.76	5.49	7.93	1.31	5.50
P	0.0286	0.1208	0.3143	0.0207	0.0131	0.0035	0.3156	0.0130
R2	0.5167	0.3730	0.2477	0.5434	0.5784	0.6646	0.2471	0.5791
MSD*	2.3076	4.3171	5.5376	5.5459	4.5450	4.0312	4.9045	6.0068

		Pre-Treat 17Mar		1 DAT 21 Mar		3 DAT 23 Mar		7 DAT 27 Mar		14 DAT 03 Apr		28 DAT 17 Apr
Treatment	Rate	n	% Active	% Active*	% Control*	% Active*	% Control*	% Active*	% Control*	% Active*	% Control*	% Active*	% Control*
diazinon		41	100	2.4 e	97.4	2.4 d	97.1	2.3 d	96.9	0.0 b	100.0	2.5 b	93.8
Garden-Ville		41	100	25.6 b	71.6	33.3 bc	60.0	15.8 cd	79.3	7.9 b	88.6	5.1 b	87.3
thiamethoxam	2.4	41	100	55.0 c	39.1	7.5 cd	91.0	4.9 d	93.6	2.6 b	96.3	2.5 b	93.8
thiamethoxam	1.2	41	100	53.8 c	40.3	15.8 cd	81.1	2.6 cd	96.6	0.0 b	100.0	0.0 b	100.0
thiamethoxam	0.6	42	100	97.6 ab	-8.1	63.4 ab	23.9	13.9 cd	81.7	2.4 b	96.5	0.0 b	100.0
thiamethoxam	0.3	40	100	82.9 b	8.2	57.1ab	31.4	5.6 d	92.7	5.6 b	92.0	5.6 b	86.3
Amdro®		40	100	100.0 a	-10.8	74.4 ab	10.8	35.0 bc	54.1	5.1 b	92.6	10.0 b	75.3
Beauveria bassiana	1x	40	100	97.3 ab	-7.8	74.4 ab	10.8	67.5 ab	11.4	55.0 a	20.3	47.2 a	-16.7
Beauveria bassiana	2x	41	100	100.0 a	-10.8	89.7 a	-7.7	80.0 a	-5.0	57.5 a	16.7	46.2 a	-14.0
control - dry		41	100	92.7 ab	-2.7	86.0 a	-3.3	78.0 a	-2.4	51.1a	26.0	29.3 a	27.7
control - water		43	100	90.2 ab	-	83.3a	-	76.2 a	-	69.0 a	-	40.5 a	-

		Pre-Treat 17Mar		1 DAT 21 Mar	3 DAT 23Mar	7 DAT 27Mar	14 DAT 03Apr	28 DAT 17Apr
Treatment	Rate	n	Ave Mound Rating	Ave Mound Rating*	Ave Mound Rating	Ave Mound Rating	Ave Mound Rating	Ave Mound Rating
diazinon		41	2.39	0.07 e	0.05 d	0.05 c	0.00 b	0.02 b
Garden-Ville		41	2.59	0.38 de	0.64 cd	0.36 bc	0.23 b	0.13 b
thiamethoxam	2.4	41	2.37	0.65 d	0.15 d	0.07 c	0.08 b	0.10 b
thiamethoxam	1.2	41	2.15	0.72 d	0.26 d	0.05 c	0.00 b	0.00 b
thiamethoxam	0.6	42	2.48	1.88 abc	1.10 bc	0.21 c	0.07 b	0.00 b
thiamethoxam	0.3	40	2.35	1.46 c	1.17 bc	0.11 c	0.11 b	0.14 b
Amdro®		40	2.37	2.17 ab	1.59 ab	0.82 b	0.10 b	0.25 b
Beauveria bassiana	1x	40	2.35	1.92 abc	1.79 a	1.62 a	1.35 a	1.31 a
Beauveria bassiana	2x	41	2.24	1.97 abc	1.95 a	1.77 a	1.60 a	1.18 a
control - dry		41	2.44	2.24 a	2.14 a	1.98 a	1.33 a	0.80 a
control - water		43	2.42	1.68 ab	1.95 a	1.83 a	1.76 a	0.88 a

		Pre-Treat 17Mar		1 DAT 21 Mar		3 DAT 23 Mar		7 DAT 27 Mar		14 DAT 03 Apr		28 DAT 17 Apr
Treatment	Rate	n**	Ave. Mound Rating	n**	Ave. Mound Rating	n**	Ave. Mound Rating	n**	Ave. Mound Rating	n**	Ave. Mound Rating	n**	Ave. Mound Rating
diazinon		41	2.39 a	44	0.15 c	47	0.22 d	49	0.21 d	46	0.11 c	53	0.47 de
Garden-Ville		41	2.58 a	44	0.57 c	47	0.88 cd	48	0.83 bc	51	0.77 bc	58	0.87 bcd
thiamethoxam	2.4	41	2.37 a	42	0.67 c	43	0.27 d	46	0.28 d	43	0.32 c	53	0.49 de
thiamethoxam	1.2	41	2.15 a	41	0.76 c	40	0.30 d	39	0.06 d	39	0.00 c	45	0.34 de
thiamethoxam	0.6	42	2.49 a	42	1.90 ab	47	1.19 bcd	47	0.37 cd	44	0.23 c	45	0.16 e
thiamethoxam	0.3	40	2.35 a	35	1.45 b	37	1.20 bcd	37	0.15 d	38	0.23 c	46	0.57 de
Amdro®		40	2.38 a	43	2.16 ab	49	1.73 abc	53	1.20 b	46	0.46 c	55	0.83 cd
Beauveria bassiana	1x	40	2.35 a	41	1.89 ab	44	1.81 abc	47	1.76 a	44	1.45 ab	53	1.63 a
Beauveria bassiana	2x	41	2.24 a	41	1.96 ab	43	1.92 ab	45	1.81 a	46	1.75 a	55	1.55 a
control - dry		41	2.45 a	43	2.25 a	45	2.19 a	46	1.97 a	55	1.63 a	62	1.46 ab
control - water		43	2.42 a	49	1.80 ab	50	1.99 ab	51	1.85 a	55	1.88 a	69	1.43 abc

		Activity Index Average From 20 Mound Sample**
Treatment/ ingredient*	Rate (product per mound)	Pretreatment	3 DAT	7 DAT	18 DAT
Untreated	NA	3	2.7 a	2.5 a	2.1 a
Amdro® (hydramethylnon)	5 tbsp	3	1.3 b	0.8 b	0.1 c
Spectracide® (diazinon)	½ cup	3	0.0 c	0.0 c	0.0 c
Orthene® (acephate)	1 tbsp	3	0.0 c	0.0 c	0.0 c

Treatment	Rate	Ave. No. Satellite Mounds*
thiamethoxam	2.4	1.35 abc
thiamethoxam	1.2	0.45 c
thiamethoxam	0.6	0.90 bc
thiamethoxam	0.3	0.75 bc
diazinon		1.40 abc
Beauveria bassiana	1x	1.85 abc
Beauveria bassiana	2x	1.65 abc
Garden-Ville		2.75 ab
Amdro®		2.40 abc
control - dry		1.95 abc
Control - water		3.25 a

Treatment	N	Score Sum	Score Mean	Sample Mean	S	Z	P >\|Z\|
Treated	16	172.5	10.7	2.4
Untreated	16	355.5	22.2	6.7
Test Statistic					355.5	3.47	0.00025

		Number of Active Mounds (Percent Control)
Treatment	Rate (lbs product per acre)	Pretreatment*	6 Weeks after Treatment	8 Months after Treatment
Amdro®	1.5	25	8 (68%)	0 (100%)
untreated	0	20	15 (25%)	2 (90%)
Logic®	1.5	24	1 (96%)	0 (100%)
Amdro® + Logic®	0.75 + 0.75	25	6 (76%)	0 (100%)

		Percent Active Mounds
Treatment	Rate (lbs product per acre)	Pretreatment*	8 DAT	15 DAT	22 DAT	29 DAT
Amdro®	1.5	100	60	95	75	50
Experimental Bait	0	100	55	70	45	40
Untreated	1.5	100	95	100	65	60

		Number of Active Mounds (Percent Control)
Treatment	Rate (lbs product per acre)	Pretreatment*	6 Weeks after Treatment
Amdro®+Orthene®	1.5	12	0 (100%)
Untreated	0	15	1 (94%)
Logic®+Orthene®	1.5	10	0 (100%)
Amdro® + Logic®	0.75 + 0.75	12	0 (100%)

PRODUCT	COST/LB	APPLICATION RATE	COST/SQUARE FT
LOGIC	$13	1#/AC	$.40
AMDRO	$7.25	1#/AC	$.20
ORTHENE	$12.50	.5#/AC	$.20

		Number of Active Mounds (Percent Control)
Treatment	Rate (lbs product per acre)	Pretreatment	6 Weeks after Treatment	5 Months after treatment
Amdro®	Skip 0.75	22	8 (67%)	0 (100%)
Extinguish®	1.5	17	2 (89%)	0 (100%)
Amdro®	1.5	21	1 (95%)	0 (100%)
Amdro® + Extinguish®	0.75 + 0.75	33	6 (82%)	0 (100%)

Description	Tractor, 160 hp	Disk Mower	Tractor, 100 hp	Sickle Mower
Fuel	0.68		0.66
Oil and filter	0.10		0.10
Repairs and Maintenance	0.11	0.38	0.11	0.52
Labor	1.15		1.69
Additional materials	0.00		0.00
Operation variable cost	$2.04	$0.38	$2.56	$0.52
Depreciation	0.93	0.52	0.80	0.52
Interest	0.69	0.60	0.73	1.06
Housing	0.00	0.00	0.00	0.00
Insurance	0.02	0.02	0.02	0.03
Operation fixed cost	$1.64	$1.14	$1.55	$1.60
Operation total cost	$3.68	$1.52	$4.11	$2.12
Summary
Operation variable cost	$2.42		$3.08
Operation fixed cost	$2.78		$3.15
Operation total cost	$5.20		$6.23

	MEAN NUMBER OF ACTIVE FIRE ANT MOUNDS/0.25 ACRE.
Treatment	Pretreatment	Post Treatment
		2 weeks	4 weeks	6 weeks	8 weeks	12 weeks	22 weeks
Two-Step Method Extinguish®/Orthene®75S - 1 lb./ac - 2 tsp./md	5.67 (a)	0.33 (c)*	0 .00 (c)	0.00 (b)	0.00 (c)	0.00 (b)	0.00 (b)
Distance®/Amdro® - 1/2 lb/ac + 1/2 lb/ac	4.0 (a)	1.33 (b c)	0.33 (c)	0.00 (b)	0.00 (c)	0.00 (b)	0.00 (b)
Distance® - 1 lb/ac	5.0 (a)	3.00 (a b c)	1.33 (b c)	0.67 (b)	0.33 (b c)	0.33 (b)	0.00 (b)
Extinguish® - 1 lb/ac	5.67 (a)	5.67 (a b)	4.67 (a b)	4.67 (a)	4.00 (a b)	4.00 (a)	0.33 (b)
untreated control	7.33 (a)	7.0 (a)	7.67 (a)	6.33 (a)	5.67 (a)	5.00 (a)	6.66 (a)

	MEAN PERCENT REDUCTION IN MOUND NUMBERS/0.25 ACRE Post Treatment
Treatment	2 weeks	6 weeks	12 weeks	22 weeks	Cost Per Acre
Two-Step Method Extinguish®/Orthene® 75S - 1 lb./ac - 2 tsp./md	94	100	100	100	$11.88 + $0.19/mound
Distance®/Amdro® - 1/2 lb/ac + 1/2 lb/ac	66	100	100	100	$5.94 + $5.89
Distance® - 1 lb/ac	40	87	94	100	$11.88
Extinguish® - 1 lb/ac	0	17	29	94	$11.88
untreated control	4	4	32	9	---

Site	Treatment	Fall 98	check 98	Spring 99	check 99
1	control	49	54	51	53
2	control	69	70	59	64
3	IGR	101	21	42	4
4	IGR	51	19	58	8
5	Advance®	88	12	72	11
6	Advance	77	14	45	7
7	IGR	50	3	7	0
8	Advance	63	6	22	1
9	control	72	67	41	58
10	Advance	53	4	28	1
11	IGR	58	7	22	2
12	control	58	66	54	61

Sample Number	Control Plot Counts	Release Site Plot Counts
1	36 (Dorymyrmex sp.)	75
2	0	0
3	0	89
4	0	99
5	0	171
6	0	39
7	12	23
8	110	164
9	197	190
10	266	7
11	33	93
12	137	147
13	133	40
14	323	1
15	171	106
16	215	96
17	253	6
18	34	8
19	50	129
20	184	187
21	191	112
22	250	86
23	259	139
24	284	94
25	0	157

Date	# of Flies	Air Temp. (C°)	Soil Temp. (C° at 4 in.)	Wind (mph)	Ant Depth (in.)
4/8	50	27	27	5-15	2
4/9	180	28-31	28	0-5	2
4/10	180	27	24	0	1
4/11	200	26-28	24	0-5	1
4/12	240	26-28	24	5	1
4/13	260	27-28	24	0-5	2
4/15	450	20-21	22	5-15	1
4/16	350	20	22	0-5	1
4/17	280	20-21	20	0-5	2
4/18	220	23-26	22	5-10	2
4/19	200	27-28	23	0-5	3
4/21	160	26-28	24	5-10	3
4/23	300	29-31	25	5-10	4
4/24	280	29-31	25	0-5	3

Date	# Mounds	# w/flies	M/F	Soil Temp (C°)	Air Temp (C°)	Wind (mph)
5/14	8	0	-	28	31	5-10
5/24	6	1	4/1	29	32	5-10
6/8	5	2	10/6	29	30	0-5
6/21	6	1	4/2	29	31	5-10
7/19	5	0	-	30	32	5-15
7/29	6	0	-	30	33	0-5
8/16	5	0	-	30	33	5-10

Species	Spring pitfall Treat	Spring pitfall Control	Fall pitfall Treat	Fall pitfall Control	Spring bait Treat	Spring bait Control	Fall bait Treat	Fall bait Control
Solenopsis invicta	96	832	0	74	412	1658	0	0
Pogonomyrmex barbatus	42	0	29	0	0	0	0	0
Pogonomyrmex comanche	37	0	41	0	0	0	0	0
Dorymyrmex flavopectus	68	12	40	0	64	0	24	0
Monomorium minimum	67	51	4	0	0	0	0	0
Linepithema pruinosus	42	0	18	9	0	0	0	0
Paratrechina vividula	30	0	0	0	0	0	0	0
Labidus coecus	12	0	0	0	0	0	0	0
Atta texana	18	0	0	0	0	0	0	0
Solenopsis krockowi	4	0	0	0	0	0	0	0

Species	Spring pitfall Treat	Spring pitfall Control	Fall pitfall Treat	Fall pitfall Control	Spring bait Treat	Spring bait Control	Fall bait Treat	Fall bait Control
Solenopsis invicta	1121	851	78	132	1621	2117	23	44
Pogonomyrmex barbatus	16	8	11	31	0	0	0	0
Dorymyrmex flavopectus	38	18	44	31	52	0	27	0
Monomorium minimum	6	24	0	0	0	0	0	0
Linepithema pruinosus	16	2	6	0	0	0	0	0

Location	% change S. invicta treatment	% change S. invicta control	% change S. invicta treatment*	% change S. invicta control*	% change Pogo. sp. treatment	% change Pogo. sp. control
Swift	-100	-45	-45	+15	-19	-100
Bowie	-88	-69	-58	-10	0	0
Wolters	-89	-61	-70	+22	0	-100
Average	-92	-58	-58	+9	-6	-67

Site	Treatment	Spring 1999	Fall 1999	Spring 2000	Fall 2000
Swift	Treated	16	14	13	13
Swift	Control	6	4	1	0
Bowie	Treated	3	3	3	3
Bowie	Control	1	1	1	1
Wolters	Treated	2	2	2	2
Wolters	Control	1	1	1	0

Treatment	No. mounds per plot (± SEM)*
fipronil 0.05 lb a.i./A	0.0833 ± 0.08 b
fipronil 0.10 lb a.i./A	0.0 ± 0.00 b
tefluthrin 1.0 lb a.i./A	0.1667 ± 0.11 b
tefluthrin 2.0 lb a.i./A	0.0 b
untreated control	1.000 ± 0.21 a