2007 Annual Report 1a.Objectives (from AD-416) Based on previous successful results showing the potential of Psytallia cf. concolor for biological control of olive fruit fly, Bactrocera oleae, in California, the objectives are to begin augmented releases of the parasitoid in regions in which the olive fruit fly has become a devastating pest; to determine the ability of the parasitoid to suppress pest populations in the open field, and ascertain its suitability for area-wide release; and, to determine the effects of ecological factors such as periods of low host abundance on the successful establishment of the parasitoid. 1b.Approach (from AD-416) The parasitoid, Psytallia cf. concolor, will be reared on Mediterranean fruit fly, Ceratitis capitata (Wiedemann), in the MOSCAMED facility in Guatemala City, Guatemala and shipped by air to Parlier, California. The parasitoids will be released in sleeve cages in a climate controlled, screened room, held for 2-3 days for mating, counted, and packaged in paper cartons for transport to release sites. Release sites have been made available by individuals and industry cooperators primarily in San Diego, Los Angeles, Kern, San Luis Obispo, Santa Barbara, San Clara, and Butte counties. The parasitoids will be released into olive trees with high olive fruit fly larval populations. Parasitoid releases will be made biweekly or monthly. Traps and infested fruit will be used to determine the olive fruit fly populations. Rate of parasitism will be calculated in samples of infested fruit exposed to the parasitoids in laboratory and greenhouse experiments, and in field tests using caged trees. Survival of the parasitoid by diapause and longevity in the field will be investigated during the period of fruit maturation. Documents Trust with CA Olive Committee. 3.Progress Report This report serves to document research conducted under a Trust Agreement between ARS and the California Olive Committee. Additional details of research can be found in the report for In-house project 5302-43000-031-00D Alternatives to Chemical Control for Stored Product and Quarantine Pests of Fresh/Dried Fruits and Nuts. A parasitoid, Psytallia cf. concolor, imported from Guatemala was released in olive orchards and ornamental trees infested with olive fruit fly in several locations in California, and subsequent generations of the parasitoid were recovered from the host. Olive fruit fly is a recently introduced exotic pest in California and has potential to devastate the canned olive and oil industry. The research to develop the parasitoid for biological control of olive fruit fly was conducted at the USDA-ARS, SJVASC, Parlier, CA, in collaboration with the California Olive Committee, Fresno, CA, and the USDA-APHIS-PPQ, MOSCAMED, Guatemala. This research helps protect the canned olive and olive oil industry in California valued at $75 million annually. Cooperator activity is monitored through technical meetings, visits to the laboratory, email exchanges, and telephone conversations.