Spatial distribution and seasonal fluctuations ofDrosophilaon Santa Catalina Island with an emphasis on the repleta species group

Santa Catalina Island is a small island off the coast of southern California and for its modest size harbors several species of flies from theDrosophilagenus. We performed an island-wide survey ofDrosophilaspecies to ascertain which species were endemic to the island and where they were most abundant. In doing so, we have assembled useful sampling information for researchers who wish to conduct field studies on Santa Catalina Island. From this survey, we determined thatDrosophila hamatofila,Drosophila mainlandi, andDrosophila mettleriwere the prominent repleta species on the island. Other repleta species encountered includedDrosophila mojavensisandDrosophila wheeleri. Non-repleta species sighted on the island includeDrosophila melanogaster,Drosophila pseudoobscura,Drosophila simulans, and an unknown species not seen before on the island. Additionally, we performed seasonal collections at two locations on the island and observed that species abundance and composition at these two sites vary between seasons. One of the seasonal sites was sampled in two consecutive summer seasons, which revealed that species composition had shifted between years, but relative abundances were approximately the same.