The Habits of a Dipteron predaceous on Mosquitos in Nyasaland

Extract

On 12th September 1919, while watching at a pool near Kotakota, Lake Nyasa, the emergence of mosquitos from their pupae, which in the case of this particular species takes place mostly between 4.30 p.m. and dusk (about 6.30 at that time of year), the writer saw at rest on some scum on the surface of the water, an Anthomyiid fly of the genus Lispa, which after a few minutes made a sudden rush at a mosquito just emerging from its pupa-case. The mosquito with its wings still unexpanded and part of its legs and the hinder segments of its abdomen still within the pupa-case was absolutely at its mercy. The fly grappling it from behind with its front legs proceeded to thrust its proboscis into the thorax. The fly was by no means timid, and it was possible to lean over and approach one’s head to watch the proceedings so closely that it was even possible to determine by its antennae the sex of the unlucky mosquito ; it was a male. The fly was captured before it had finished its meal, lest it should suddenly fly up and escape.