Courtship in Drosophila montana: the effects of male auditory signals on the behaviour of flies

Abstract

In Drosophila montana (a species of the D. virilis group) the sounds produced by the courting male are a prerequisite for copulation. The mating behaviour of four experimental groups was recorded. Two groups consisted of single pairs of normal flies with successful and unsuccessful courtship, respectively. The third group consisted of single pairs of normal males and deaf females and the fourth group of single pairs of mute males and normal females. In successful courtships (i.e. those ending in copulation) touching and licking by the male led to female standing. Female standing led to male wing vibrating, male wing vibrating to female wing lifting, and female wing lifting to copulation. In unsuccessful courtships, the males did not vibrate their wings in response to female standing. In the groups lacking male auditory signals (deaf females or mute males) the females hummed their wings in response to male licking and wing vibrating. Although the males responded to wing humming by more licking and by producing more sounds, the courtships did not proceed to copulation. It is concluded that the willingness of the female to mate with a conspecific male depends on the detection of sound at the appropriate time in the courtship sequence as a response to female behaviour.