Intrapopulational variation of olfactory responses in Drosophila melanogaster.

The existence of genetic variability for olfactory response within natural populations of Drosophila melanogaster was studied in two newly collected natural populations from two very different habitats, the Sandiche population, from a very heterogeneous environment, and the Los Areneros population, from a very homogeneous one. Intrapopulational variability was estimated over approximately 50 isofemale lines derived from each population. Results confirm significant differences in olfactory response to ethyl alcohol and acetaldehyde in both populations and to ethyl acetate in the Sandiche population. The differences were due partially to common components of the olfactory responses to different chemical (nonspecifics) in the Sandiche population, but they were specific for the stimulus in the Los Areneros population.