Female courtship summation in Drosophila melanogaster

To examine the concept of female courtship summation in Drosophila melanogaster, two experiments previously reported in the literature, the first involving repeated matings of females and the second progressive removal of the males' wings, were repeated. The present results do not convincingly support the concept of female summation of stimuli provided by the males' courtship. The results of the first experiment also refute the idea that low male courtship intensity leads to long courtships. These results also fail to support an earlier suggestion that females summate the sine rather than pulse song component of the males' wing vibration. Instead, the variation in courtship duration appeared to result from the inverse hyperbolic relationship between the male latency to courtship and the subsequent courtship duration. Thus short male latencies led to longer courtship durations. This is interpreted as resulting from a female latency period during which the female is too agitated to receive the male's courtship, and after which she mates upon recognizing the male as conspecific. In addition, very long courtships largely resulted from additional agitation of the female by the male's courtship. Long courtships therefore appear to be an artifact of the experimental situation and the established concept of female courtship summation, which is supposed to explain them, is unnecessary. The implications of this conclusion are discussed.