ADAPTATIONS OF GALL WASPS OF THE GENUS DIPLOLEPIS (HYMENOPTERA, CYNIPIDAE) AND THE ROLE OF GALL ANATOMY IN CYNIPID SYSTEMATICS

Adaptations and attributes of gall-inducing cynipid wasps are reviewed to emphasize that differences in life cycles and anatomical features of their galls are just as useful for systematic purposes as are struc tural differences in the adult insects themselves. The extent to which cynipid wasps have specialized is illustrated by the genus Diplolepis , all species of which are restricted to native and introduced roses a nd induce structurally distinct galls. Various aspects of Diplolepis b iology including life cycles, host specificity, and gall development a nd anatomy are reviewed. The biologies of two species of Diplolepis th at commonly co-exist in the same habitat in central Ontario are then e xamined in detail. Diplolepis polita (Ashmead) induces a single-chambe red gall on the leaves of Rosa acicularis Lindl. whereas Diplolepis sp inosa (Ashmead) induces a multi-chambered gall on the stems of Rosa bl anda Ait. Differences in life cycles, distribution, host and organ spe cificity, oviposition, gall initiation and development, along with dif ferences in the communities of parasitoids and inquilines attracted to the galls, confirm the existence of distinct species and allow some s peculation on their ecological and phylogenetic relationships.