Pest Management Solutions -- University of Texas
Pest Management Solutions -- University
of Texas
Pheromone Control of Reproduction in Fire Ant Colonies
Principal Investigator:
Edward
L. Vargo
Brackenridge Field Laboratory and Department of
Zoology
University of Texas
Austin, TX 78712
Phone: 512/471-2825; Fax
512/475-6286
Email: edvargo@mail.utexas.edu
Funding Amount/2 Years: $148,228
Relevance/Implication of Project:
Research on naturally occurring chemicals that regulate physiology
and behavior of imported fire ant colonies is one of the target areas listed
under Pest Management Solutions in the state initiative. Pheromones play a
central role in regulating reproductive development in S. invicta
colonies. Knowledge of what the chemical constituents are and how they function
could be used to develop species-specific forms of birth control which would
disrupt reproduction in the imported fire ant but leave native ants
unaffected.
Summary of Work to be Done:
The
proposed research will continue and expand our work on queen pheromones and
their role in regulating reproduction in colonies of the imported fire ant. Five
effects of queen pheromones are currently under study in our lab: 1) inhibition
of new virgin queens from undergoing reproductive maturation; 2) mutual
suppression of egg laying among co-habiting queens in multiple-queen colonies;
3) inhibition over the production of new queens and males; 4) execution of young
queens as they begin to lay eggs; 5) ability of queens to attract workers. The
planned work will focus on the isolation and identification of the active
compounds responsible for these different pheromonal effects, especially the
first and last effects because of the existence of sensitive bioassays to study
them. Previous work by our group and others has identified the poison gland as
the source of both the pheromone inhibiting reproductive maturation in virgin
queens and the pheromone mediating attraction of workers to queens. Evidence to
date indicates that both of these pheromonal effects is mediated by a blend of
compounds. We have made substantial progress in isolating and identifying some
of the compounds inhibiting virgin queen reproductive maturation. We will
continue this work to fully characterize the chemical composition of this
reproduction suppressing pheromone. We will also work toward the isolation and
identification of the compounds used by queens to attract workers.
Identification of these pheromones may lay the groundwork for development of
novel biopesticides to suppress imported fire ant
populations.