COURTSHIP SUCCESS AND MULTIVARIATE-ANALYSIS OF SEXUAL SELECTION ON MORPHOMETRIC TRAITS IN DROSOPHILA-BUZZATII (DIPTERA, DROSOPHILIDAE)

Using wild-reared flies, we examined sexual selection on five phenotyp ic traits (thorax length, wing length, tying width, head width, and fa ce width) in Drosophila buzzatii, by scoring copulatory status in nine mass mating cages. Only male face width was identified as a direct ta rget of sexual selection in an analysis of selection gradient, while i ndirect selection was present on all other studied traits, as expected from their correlations with face width. In contrast to males, there was no indication of selection in females. Nor was there evidence of a ssortative mating. The suggested direct selection on face width seems to rake place during licking behavior of the courtship and might be re lated to courtship feeding. This study suggests that courtship success gives rise to indirect selection on body size.