Sustainable Solutions
University of Texas
Principal
investigator:
Lawrence E. Gilbert
Section of Integrative
Biology
University of Texas
Austin, TX 78712-1064
Email: lgilbert@mail.utexas.edu
Funding Amount/2 Years: $357,430
Relevance/Implication
of Project:
Biological control of imported fire ants will constitute the ultimate in
sustainable and economic solutions to this problem species. Given their
demonstrated effects on host fire ants, phorid flies of the genus
Pseudacteon are
likely to be at least one key element of any future overall biocontrol success.
Basic research on these insects is fundamental to the successful rearing and
establishment of South American species in North America.
Summary of Work to be Done:
Phorid flies of the genus Pseudacteon constitute a large group (>
25) of parasitoid species primarily associated with the fire ant genus Solenopsis. Laboratory and field experiments have demonstrated that some
Pseudacteon species are highly specific to the red imported fire ant,
S. invicta.
The demonstration that attacks of egg-laying phorids disrupt important
activities of ant hosts such as foraging for food, has led to the hypothesis
that these flies play an important role in the natural regulation of fire
ant populations. Furthermore, field observations in South American localities
indicate that suites of 3. 5 phorid species that attack the same ant
colony in complementary ways could represent the ultimate in phorid pressure on
fire ants. However, only two species of ant-attacking phorid flies have been
successfully cultured to date. Thus, many key life-history details, such as
where mating occurs, how flies locate hosts, level of host specificity, how
flies survive harsh seasons when ants are inactive, and how pupal survival
varies depending on microsite, are virtually unknown. Therefore, the parts of
this project are conceived to work in concert and in an integrated fashion to
broaden our comparative knowledge of critical aspects of phorid biology in order
to bring additional species into culture; to improve the mass rearing methods of
those in culture, such as Pseudacteon tricuspis; and to improve methods
of introducing the flies in Texas. The ultimate long term goal is to develop
methods for mass-rearing and field introductions of any Pseudacteon species which ecological and behavioral
studies indicate may possess potential for the biocontrol of fire
ants.