The primary purpose of the sabbatical is to allow the principal investigator to collaborate with Dr. Stuart Barker (University of New England, Armidale, Australia) on an ecological genetic analysis of cuticular permeability and epicuticular hydrocarbon composition in Australian populations of the cactiphilic fly, Drosophila buzzatii. Within and among population genetic variation for the two traits--and for their plastic response to variation in ambient temperature and humidity regimes--will be quantified using a half-sib experimental design. This analysis will repeated three times--during the annual summer population bottleneck, during recovery from the bottleneck, and when population sizes are maximal--to assess possible temporal changed in G-matrices. Mate choice experiments will assess the role of epicuticular hydrocarbons in the mating system of D. buzzatii. Ancillary experiments will quantify the impact of dehydration on reproductive performance of D. buzzatii. The sabbatical with Dr. Barker will provide the principal investigator with conceptual background and genetic techniques required to conduct his own program of research into the evolution of physiological adaptations and acclimation responses to environmental variation. A second project--field and laboratory studies o australian cicada thermobiology--will augment the principal investigator's work with U.S. species and lead to phylogenetic analysis of patterns of body temperature regulation in cicadas.
