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Title: Biological controls investigated to aid management of olive fruit fly in California

Author
item DAANE, KENT - UNIV CALIFORNIA
item JOHNSON, MARSHALL - UNIV CALIFORNIA
item PICKETT, CHARLES - CALIF DEPT FOOD&AG
item SIME, KAREN - University Of California
item WANG, XIN GENG - University Of California
item NADEL, HANNAH - UNIV CALIFORNIA
item ANDREWS, JOHN - UNIV CALIFORNIA
item Hoelmer, Kim

Submitted to: California Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2008
Publication Date: 1/21/2011
Citation: Daane, K., Johnson, M., Pickett, C., Sime, K.R., Wang, X., Nadel, H., Andrews, J., Hoelmer, K.A. 2011. Biological controls investigated to aid management of olive fruit fly in California. California Agriculture, 65(1):21-28.

Interpretive Summary: The recent widespread and rapid establishment of the olive fruit fly in California necessitated immediate changes in existing olive IPM programs. After finding that resident natural enemies do not provide adequate control, researchers began a worldwide search for parasitoids. Foreign exploration took researchers to the Republic of South Africa, Namibia, Kenya, India, China, and other countries. Parasitoids were shipped to California and most were studied in quarantine laboratories to determine the best species for release. Two parasitoid species – Psyttalia lounsburyi and Psyttalia concolor – are now being released throughout California’s olive growing regions, and researchers are studying their effectiveness as biological control agents of olive fruit fly.

Technical Abstract: The recent widespread and rapid establishment of the olive fruit fly in California made necessary immediate changes in existing olive IPM programs. After determining that resident natural enemies (various generalist predators and a previously unknown parasitoid) that have been found attacking olive fruit fly do not provide adequate control of the fly, researchers initiated foreign exploration for parasitoids in Eurasia and Africa. Surveys and collections were made in the Republic of South Africa, Namibia, Kenya, India, China, and other countries. Collections for specialized agents were made primarily from wild olive (Olea europaea subsp. cuspidata) from south to northeast Africa, and from southwest Asia to central China. The highest yield of parasitoids came from collections in South Africa, Namibia, and Kenya. The highest levels of parasitism were found in Kenya collections, where the braconid wasps Psyttalia lounsburyi and Utetes africanus together parasitized over 57% of collected flies, followed by collections in Pakistan (37% parasitism by P. ponerophaga) and Republic of South Africa (28% parasitism by P. lounsburyi, Bracon celer, and U. africanus). The most common species found over all collections were Psyttalia lounsburyi and P. concolor. Parasitoids obtained in collections were shipped to California, and most of these have been evaluated or are still under study in quarantine laboratories to determine which species are suitable for release. Two parasitoid species – Psyttalia lounsburyi and Psyttalia concolor – are now being released throughout California’s olive growing regions, and researchers are currently studying their effectiveness as biological control agents of olive fruit fly. Release permits for two additional species are pending.