Aircraft Applications of Insecticides in East Africa. VIII.—An Experiment against the Tsetse Fly, Glossina swynnertoni Aust., in an isolated Area of Thronbush and Thicket

Abstract

An isolated area of 2,200 acres of thicket and thronbush in the Central Province, Tanganyika, was treated from the air with a DDT-in-oil aerosol in an attempt to eliminate the tsetse fly, Glossina swynnertoni Aust. Eight applications of 0·25 lb. technical DDT per acre were planned to be done at fortnightly intervals.Delays due to unseasonal bad weather reduced this to seven at a slightly higher rate and over a longer-period.G. swynnertoni was reduced from an apparent density of about 7 to zero at the end of the second application. No flies were caught after the fifth application for a period of six months.It is not possible to say whether the few caught since then have been brought in or are the offspring of survivors of the insecticidal treatment.This experiment was more successful than that on the Galapo Block in the same ares, to a highly significant degree, and this is attributed to the vulnerability of the smaller population present. It was doubtfully better than the first treatment of the North Block, also in this area, because the increase in population in the latter block may have been assisted by immigration.