The behavioral phenotype and mating behavior of two inbred strains of Drosophila melanogaster

Time to copulation was measured in matings within and between two inbred Drosophila melanogaster strains, Edinburgh (E) and 6C/L, using groups of one or five flies of each sex. The E males, which mated faster, usually mate with E females, which are less likely to be fertilized and have fewer progeny whose adult viability is lower. Although generally E males mated far faster with E females than did 6C/L males, there was no difference between the males when with 6C/L females. This need not imply any mating discrimination by E females, but only differences between the strains in the use of preening as a general repulsion movement toward other flies. It is suggested that a greater variety of behavioral and other characteristics (the "behavioral phenotype") should be considered in studies of mating speed and assortative mating, especially where mating speed is being considered as a major component of fitness.