Variation and repeatability of courtship song characters among wild-caught and laboratory-reared Drosophila montana and D-littoralis males (Diptera: Drosophilidae)

In Drosophila montana and D. littoralis (species of the D. virilis group), females use male courtship song in their mate choice in wild preferring males which produce short and dense sound pulses (Aspi and Hoikkala, 1995). In the present study these song characters were found to be repeatable among overwintered males. Male progenies of wild-caught flies reared in the laboratory, and in D. montana also the males collected in wild before overwintering, exhibited very little variation between males in these characters. Contrary to pulse characters, pulse train characters measured for D. montana song varied significantly between laboratory-reared males. Our findings suggest that in D. montana and D. littoralis song characters playing a part in sexual selection in the wild are more condition dependent than song characters which are not the direct targets of female choice.