Sexual Communication in Yellowjackets (Hymenoptera: Vespidae)

To determine if and how pheromones mediate sexual communication of yellowjackets [Dolichovespula arenaria, D. maculata, Vespula alascensis, V. pensylvanica, V. squamosa], I took three approaches: (1) In field trapping experiments, I baited traps with a virgin queen (gyne) or a male and tested for their ability to attract prospective mates. I found that only gynes of D. arenaria attracted males. (2) In laboratory Y-tube olfactometer experiments with D. arenaria, D. maculata and V. pensylvanica, I used sibling or non-sibling gynes as a test stimulus, and found that only D. maculata gynes attracted conspecific males, provided they were non-siblings. These results imply an olfactory-based mechanism of nestmate recognition and inbreeding avoidance. (3) I tested the hypothesis that cuticular hydrocarbons (CHCs) differentiate sex, caste, and nest membership. I found that each caste had specific CHC profiles. My data demonstrate the diversity and complexity of sexual communication in yellowjacket wasps, and inspire follow-up studies to identify the sex pheromones.