Nocturnal mating in Taeniorhynchus (Mansonioides) uniformis (Theobald).

Abstract

MATING in Taeniorhynchus (Mansonioides) uniformis (Theobald) was observed taking place on the night of December 7, 1951, between 18.30 hr. and 22.30 hr., while all-night trapping of mosquitoes was in progress at a cattle-shed in a village on the outskirts of Colombo. On this night it was quite dark by 18.15 hr., but for the light of the moon which was two days after the first quarter. Mating activity took place in three stages. In the first and third stages, which lasted from 18.30 hr. until 19.30 hr. and during 20.30 hr.–22.30 hr. respectively, mating was in active progress. In between these two periods of considerable activity there occurred a lull from 19.30 hr. until 20.30 hr., during which far fewer pairs of mosquitoes were observed copulating, and relatively few males were found coming into the trap. But at no time during this period of four hours was mating not in progress, and 292 females and 195 males were caught; these numbers represented only a small proportion of T. uniformis in the trap, for owing to great activity among the mosquitoes, catching was seriously interfered with. No mating occurred after 22.30 hr.