A male courts a female by dancing side-to-side, forequarters held high, displaying his elongated antennae and vibrating his elongated forelegs. A receptive female responds by spreading her forelegs to contact the male's long forelegs. The male somersaults over her forequarters and flips over to land on her back and lock onto her genitals. After several minutes of copulation, the female ejects a large part of the semen and swallows it. Such behaviour seems to correlate with the success of fertile egg production. Given such elaborate behavioural and morphological adaptations, waltzing flies are of interest as a model system for studying of the evolution of sexual dimorphism.