A study of the breeding distribution of Glossina morsitans Westw. in northern Botswana

Abstract

A year-long survey of the breeding of Glossina morsitans Westw. in the Moremi Game Reserve, northern Botswana, was based on transect counts of pupae and empty puparial cases under logs. Levels of breeding were lowest during the hot dry months, and were similar in riverine woodland and mopane even when the latter was leafless: mopane contributed most pupae (65.7%) to the total population because of its greater area. Pupae to cases ratios decreased between February and November due to accumulation of cases, which apparently were largely destroyed in the rains. Comparison of holes, scattered sites and logs in a second survey showed that holes were important breeding sites during the hot dry season, possibly due to their higher humidity, but that at other times most breeding occurred in scattered sites. During the rains scattered sites contained the fewest dead pupae, and holes the most. There was a preference by G. morsitans for shaded sites. Breeding appeared to be depressed during the rains, possibly due to reduced availability of food hosts, particularly warthog.