SWARMING AND MATING OF CHIRONOMUS RIPARIUS (DIPTERA: CHIRONOMIDAE)

Abstract

By restricting the swarming behaviour of Chironomus riparius Meigen, in a series of five swarm suppression cages, it was found that reduced swarming resulted in fewer matings and less oviposition. With total suppression of swarming no matings occurred.When swarming volume was incrementally reduced vertically or horizontally, it was found that the minimum vertical or horizontal dimension for swarming to occur was 2–3 cm. The mating rate was determined by the detection of labelled spermatozoa in autoradiographs. Thus swarming appears to have an epigamic function in C. riparius and is an essential precursor to mating and oviposition.