HOST RECOGNITION AND THE STUDY OF A CHEMICAL BASIS FOR ATTRACTION BY CUCKOO BUMBLE BEES (HYMENOPTERA, APIDAE)

Species of Psithyrus (Hymenoptera; Apidae) are obligate bumble bee social parasites. In this study, females of P. vestalis and P. ashtoni were presented with pentane extracts prepared from different body parts of queens of their respective host species, Bombus terrestris and B. terricola. Parasites of both species were capable of distinguishing host bees from other bumble bee species using chemical cues contained within extracts. Among extracts of several body parts presented to parasites, the abdomen produced the greatest behavioral response, with Dufour's gland and terminal tergal segments eliciting the greatest response among abdominal regions. Extracts of these two body parts obtained from B. terrestris queens shared a number of compounds, identified by GC-MS. Among the identified compounds are a number that have been reported to be of importance in bee sociochemistry.