Survey for parasitoids of apple maggot complex (Diptera: Tephritidae) in Washington State

The Rhagoletis pomonella complex of flies (including the apple maggot (AM) or R. pomonella, and R. zephyria) provides a compelling example of sympatric host shifting that led to distinct forms of Rhagoletis flies that preferentially attack apple, hawthorn, or snowberry. Immature stages of both fly species infest the host fruit and are, in turn, attacked by small wasp parasitoids in the families Braconidae, and to a lesser extent, Pteromalidae. To minimize the impact that AM can potentially have on the apple industry, Washington State Department of Agriculture (WSDA) in collaboration with the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) are currently investigating biological control options for the R. pomonella complex by conserving/encouraging the establishment of parasitic wasps.

This project not only complements current R. pomonella detection and quarantine programs, but provides a control option that can be encouraged throughout Washington regardless of whether the area is pest-free (but threatened by R. pomonella) or quarantined for R. pomonella.