Submitted to: Florida Entomologist
Publication Type: Research Notes
Publication Acceptance Date: January 28, 2005
Publication Date: March 10, 2005
Citation: Vazquez, R.J., Porter, S.D. 2005. Re-confirming Host Specificity of the Fire Ant Decapitating Fly Pseudacteon curvatus after Field Release in Florida. Florida Entomologist. 88(1): 107-110. Technical Abstract: Critics of biological control programs have argued that there is a lack of post-release monitoring on nontarget effects arising from released exotic insects. Others have argued that releases of nonindigenous species on target organisms have led to reduction in populations of nontarget species due to inappropriate protocols on host specificity of these nonindigenous species. Scientists working for the USDA's Agricultural Research Service at the Center for Agricultural, Medical and Veterinary Entomology located in Gainesville, Florida studied the host specificity of decapitating phorid flies in the genus Pseudacteon prior to release from quarantine facilities for biological control of the red imported fire ant, Solenopsis invicta. The purpose of this new study was to confirm laboratory results that the small decapitating phorid fly, Pseudacteon curvatus originally collected from red fire ants in Formosa, Argentina, is specific to red imported fire ants and that nontarget effects to the native ant fauna in Florida is minimal to nonexistent. Results showed that the Formosa biotype is specific to red imported fire ants. Pseudacteon curvatus flies were not attracted to any of 15 non-Solenopsis ant species used in the tests. When P. curvatus was tested on the native fire ant, Solenopsis geminata, flies were attracted at very low rates (<5% of that with S. invicta) but virtually no oviposition attempts were observed. Results were consistent with laboratory predictions except attraction rates to nontarget fire ants in the field were much lower than in small laboratory test chambers. Overall, this study demonstrates that release of this decapitating fly has been safe and poses no threat to native animals.