Epigamic display and unique mating position inWyeomyia arthrostigma (Diptera: Culicidae)

The mating behavior ofWyeomyia arthrostigma is more complex than that reported forW. smithii. Like some other genera in the tribe Sabethini, flyingW. arthrostigma males approach females perching on vertical sticks. A male aligns himself next to a female by seizing her wing and flipping sideways to land next to her, rather than beneath her. He then performs a series of abdominal bobbing movements, the pair achieves superficial genital coupling while the male's proboscis rotates and snaps down, and the antennae spread farther apart. Finally, the pair shifts to full copulation, and in this phase insemination occurs. In the copulatory position the abdomens of male and female are almost at right angles to each other, made possible by a twisting of the male's terminal segments. The nature of the mating process and its similarity to some elements ofSabethes andTopomyia mating indicate that males may be performing a courtship display.