BIOLOGY OF THE GALLER DIPLOLEPIS-ROSAEFOLII (HYMENOPTERA, CYNIPIDAE),ITS ASSOCIATED COMPONENT COMMUNITY, AND HOST SHIFT TO THE SHRUB-ROSE-THERESE-BUGNET

Diplolepis rosaefolii (Cockerell) induces a lenticular gall on the lea ves of various roses across Canada. In Ontario and Quebec, D. rosaefol ii is found only on Rosa acicularis Lindl., and its galls are inhabite d by eight species of parasitoids, the most common being Chrysocharis pentheus (Walker), Orthopelma luteolator (Gravenhorst), and Eupelmus d ryorhizoxeni Ashmead. Parasitoids and the inquiline Periclistus sp. ma ke up 48-62% of gall inhabitants. Here we report a population : of D. rosaefolii on the hybrid rugosa shrub rose Therese Bugnet in a field o f experimental roses in Quebec. Only two species of parasitoids and on e specimen of Periclistus sp. were associated with these galls.