(Afromyia wittei Vanschuytbroeck, Sphaeroceridae, Sphaerocerinae)
If Fred Astaire was an insect. (Afromyia wittei Vanschuytbroeck, Sphaeroceridae, Sphaerocerinae)
This week’s insect, Afromyia wittei, is an adult fly of the family Sphaeroceridae, in the subfamily Sphaerocerinae. The genus Afromyia is an African endemic (i.e. occurs only in Africa). Six species of Afromyia have been described. For a small genus Afromyia has a wide distribution, known from East, West, Central and Southern Africa. The most widespread species is A. wittei (Vanschuytbroeck, 1948). The biology of A. wittei is poorly known, but adults have been sampled from rotten Raphia palms (Arecaceae) and by sweeping in rainforest. Brave little flies, they have also been collected from elephant dung. They can be differentiated from other sphaerocerids by the combinaton of a highly convex scutum (middle part of the body), bulges on other parts of the mesonotum, and the absence of a large recurved apical spine on the hind tibia. To me, A. wittei looks like he’s on his way to the dance.
The dipteran family Sphaeroceridae is easily identified by examination of the hind legs (the legs of adult flies are divided into five major parts. Starting at the base of the leg the divisions are coxa, trochanter, femur, tibia and tarsus.) The last segment, the tarsus, is further divided into five smaller segments. Among the many families of Diptera the first of these tarsal segments is normally much longer than the other four. However, in the Sphaeroceridae, the 1st segment of the tarsus is shorter than the 2nd tarsal segment. It is also often dilated, as it is in A. wittei.. Sphaeroceridae are saprophagous, feeding on the rich liquids of decaying organic matter, dung, and carrion. As always, exceptions occur, not surprising given the incredible diversity of insects. Females of the species of the sphaerocerid genus, Ceroptera, hitch rides on ball-rolling dung beetles, later ovipositing on the dung after the beetle prepares the brood tunnel.
Yes, looks can be deceiving, but If Fred Astaire was a fly he might have been an Afromyia.
Credits: Dr Robert Copeland