2010 Annual Report 1a.Objectives (from AD-416) Facilitate collection, rearing and evaluation of new species of fire ant decapitating flies from South America for field release and transfer to APHIS mass-rearing program. 1b.Approach (from AD-416) Scientist in Gainesville, Florida will collect and evaluate new species of fire ant decapitating flies in South America. Techniques will be tested for rearing the flies so that a laboratory colony can be established. The host specificity of the flies will be tested and, if appropriate, application will be made for field release. Once permits are obtained, test field releases will be conducted, the flies will be transferred to APHIS, and APHIS personnel will be trained in rearing procedures. 3.Progress Report This project is related to Objective 2 of this in-house project: Expand current biocontrol efforts by discovering and developing new parasites and pathogens; improving mass culture and field release systems; and defining host specificity of natural enemies. Researchers at the USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, concluded host specificity tests and sent a 27-page technical petition to the North American Plant Protection Organization (NAPPO) requesting permission to remove the little fire ant decapitating fly Pseudacteon cultellatus from quarantine and release it in the field as a self-sustaining fire ant biological control agent. After this petition was approved by NAPPO, both state and federal regulator officials issued the permits needed to begin field releases. At this point, the colony of P. cultellatus flies were transferred to the APHIS rearing facility in Gainesville, Florida along with the technology needed to mass rear these flies for field release. ARS researchers also provided continued support and technical assistance for the APHIS effort to mass rear and release three other species of phorid decapitating flies in states infested with imported fire ants. Specifically, they provided voucher specimens so APHIS cooperators could identify flies captured at release sites and also verified identifications. ARS researchers also developed several protocols for removing unwanted species of flies from colonies based on differing rates of growth and development. Monitoring: ARS and APHIS personnel regularly discussed progress and objectives by telephone and direct visits.