Larval reaction to alcohol as an indicator of resource utilization differences between Drosophila melanogaster and D. simulans.

Newly hatched larvae of Drosophila melanogaster derived from southern Australian populations (37-38° S) have a strong preference for agar containing alcohol, while larvae of sympatric populations of Drosophila simulans show no initial preference. The alcohol preference of a more northern D. melanogaster population (10° S) is lower due to a high level of variability among isofemale strains. This agree with the general principle of decreasing biological diversity with increasing latitude, and is shown here for a simple behavioural trait with a chemical basis. The results are of application to the ecological biology of resource utilization in the wild.