|Gilbert, Lawrence - UNIVERSITY OF TEXAS|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 30, 2004
Publication Date: December 7, 2004
Citation: Porter, S.D., Gilbert, L.E. 2004. Assessing host specificity and field release potential of fire ant decapitating flies (Phoridae: Pseudacteon). Van Driesche, R.G., Reardon, R., editors. USDA Forest Service, Morganton,WV. Assessing host ranges for parasitoids and predators used for classical biological control: a guide to best practice. 152-176. Technical Abstract: Fire ant populations in their South American homelands are about 1/5 to 1/10 of populations normally found in North America. This intercontinental difference in fire ant densities is not explained by differences in climate, habitat, soil type, land use, plant cover, or sampling protocols. Escape from numerous natural enemies left behind in South America is the most apparent explanation for the intercontinental population differences. Classical or self-sustaining biocontrol agents are currently the only current hope for permanent regional control of fire ants. Successful release of biocontrol agents will not eradicate imported fire ants, but it could help tilt the ecological balance in favor of native ants. If this happened, fire ant populations in the United States could be reduced to levels similar to those in South America. Fire ant decapitating flies in the genus Pseudacteon are being evaluated for fire ant biocontrol. This chapter was written by a scientist at the USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida and a scientist at Brackenridge Field Laboratory and the Section of Integrative Biology, University of Texas at Austin. The chapter was written to discusses the biology of fire ant decapitating flies and detail the process of studying their host specificity and evaluating potential risks and benefits associated with their field release. The chapter discusses how information on host range from the literature, field observations, field tests, no-choice tests and choice tests was used to evaluate the environmental safety of releasing decapitating flies in the field as fire ant biocontrol agents. Results of these tests predicted that that fire ant decapitating flies would be very host specific and would present no danger to anything except for fire ants. Post-release host range tests have so far confirmed the pre-release predictions.