Resource Partitioning in Five Domestic Drosophila Species and Its Relationship to Ethanol Metabolism.

Abstract

The distributions of 5 species of Drosophila living in the vicinity of a domestic compost heap in Canberra, Australia, were compared across traps baited with different fruits and vegetables. In both adults trapped directly on the baits and those derived from eggs laid on the baits, D. busckii Coq. made up about 2% of the sample, D. hydei Sturt. about 1% and D. immigrans Sturt. 7%. The overall frequency of D. simulans Sturt. was 80% in the trapped adults but 50% in emergences, while D. melanogaster Mg. represented 9% of trapped adults and 37% of emergences. In both types of collection, the frequency of D. busckii relative to the other species was highest on vegetables, the relative frequencies of D. hydei and D. immigrans were highest on melons and the relative frequencies of D. simulans and D. melanogaster were highest on fruits. Overall, the relationship between the frequency of each species and the ethanol contents of the baits was significant and negative for D. busckii and D. immigrans, non-significant and negative for D. hydei, non-significant and positive for D. simulans, and significant and positive for D. melanogaster. These differences were correlated with differences between the species in alcohol dehydrogenase activity.