Genetic analysis of cuticular hydrocarbons and their effect on courtship in Drosophila virilis and D-lummei

Genetical factors controlling the cuticular hydrocarbons (CHC) of Drosophila virilis and D. lummei, and the effect of CHC on female attractivity were studied. A strong sexual dimorphism was found in D. virilis where (Z)-10-heneicosene and (Z)-11-pentacosene were major CHC for males and females, respectively. In D. lummei, (Z)-9-pentacosene was the major CHC for both sexes. These CHC are under a complex genetical control: the level of male (Z)-10-heneicosene was mainly sex-linked; chromosome 2 exerted a marked hypermorphic effect on it as well as on female (Z)-11-pentacosene; other autosomes had additional smaller effects on the CHC. Further, these two species showed differences in the double bond position pattern: Monoenes, with double bonds in (Z)-11 or (Z)-13, were more abundant in D. virilis (monoenes-vi), while monoenes, with double bonds in (Z)-7 or (Z)-9, were more abundant in D. lummei (monoenes-lu). In agreement with previous studies of perfumed dummies, experiments with live females showed that a higher proportion of (Z)-11-pentacosene or of monoenes-vi induced D. virilis males to court sooner. On the other hand, monoenes-lu showed antagonistic effects.