CHEMICAL COMMUNICATION IN HAWAIIAN DROSOPHILA

We are interested in elucidating the extent to which lekking Hawaiian Drosophila species have diverged from their continental counterparts, which engage in sexual behavior at communal food sources, with regard to the chemical communication systems that the flies employ. According ly, we have analyzed flies from three closely related Hawaiian Drosoph ila species in the adiastola subgroup. These species are of interest b ecause the males engage in a unique behavior: while courting, they rai se their abdomens over their heads and emit anal droplets. Analysis of the flies' behavior, the hydrocarbons in males' anal droplets, and ma les' cuticular hydrocarbons suggest that females' responses to males m ay be mediated by cuticular pheromones and/or pheromones in males' ext ruded droplets that enable the females to distinguish conspecific from heterospecific males. Conversely, perception of cuticular hydrocarbon s from conspecific females enables D. adiastola males to distinguish f emales from a closely related species from conspecific females. On the basis of these observations, we suggest that the adiastola subgroup s pecies are unique among drosophilids in that they utilize an anal drop let-mediated pheromone communication system, some or all components of which are species specific. However, the lekking Hawaiian Drosophila species are similar to D. melanogaster and related continental species in that the Hawaiian flies employ a cuticular pheromone communication system, some components of which are sex and species-specific.