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 gro up), females use male courtship song in their mate choice in wild pref erring males which produce short and dense sound pulses (Aspi and Hoik kala, 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 colle cted in wild before overwintering, exhibited very little variation bet ween males in these characters. Contrary to pulse characters, pulse tr ain characters measured for D. montana song varied significantly betwe en laboratory-reared males. Our findings suggest that in D. montana an d D. littoralis song characters playing a part in sexual selection in the wild are more condition dependent than song characters which are n ot the direct targets of female choice.