OPIINE PARASITOIDS (HYMENOPTERA: BRACONIDAE) OF RHAGOLETIS POMONELLA AND R. ZEPHYRIA (DIPTERA: TEPHRITIDAE) IN THE WILLAMETTE VALLEY, OREGON

Abstract

AbstractTwo species of opiine (Braconidae) parasitoids, Opius lectoides Gahan and O. downesi Gahan parasitized Rhagoletis zephyria Snow and R. pomonella (Walsh) in the Willamette Valley, OR. Almost equal numbers of O. lectoides and O. downesi were recorded from R. zephyria, whereas about 91% of the opiines associated with R. pomonella were O. downesi. In general, percent parasitization of R. pomonella was variable from sample to sample, but substantially higher on hawthorn than on apple fruit. It appears that both the opiine species have made a rapid host shift from R. zephyria to newly introduced populations of R. pomonella.