Chemical mate choice copying in Drosophila melanogaster

Mate choice is a critical decision especially for females that requires
time and energy to assess potential partners’ genetic quality.
Consequently, in many species, females have evolved the ability to utilize
social information by copying the mate choices of others, usually based on
visual cues. However, many species, especially invertebrates, primarily
rely on chemical not visual cues. Using chemical rather than visual cues
provides several advantages such as not requiring active observation of
copulations. Despite that, empirical evidence for the existence of
chemical mate choice copying is scarce. Using Drosophila melanogaster, we
provide the first demonstration of chemical mate choice copying. Females
exposed to a recently mated select the same male genotype as the
demonstrator female mated with at a higher frequency than expected by
chance. Chemical mate choice copying requires sensing both male and female
cues, which might indicate that other females have chosen that male
genotype. Our work suggests that females, in the presence of mated
females, increase choosiness at the virgin stage, elevating sexual
selection on male traits. This study provides novel evidence that
exploiting social information is more prevalent in flies than previously
assumed.