The following report deals with the investigation into the bionomics of Glossina morsitans being carried out in Northern Rhodesia on behalf of the British South Africa Company.

On my return from leave in July 1914 it was decided to form a base camp close to the railway line. Several areas in the neighbourhood of Broken Hill where fly was reported as being very thick were first examined, but were found from various causes to be unsuitable. A site was finally selected at the source of the Lukanga River, about four miles from the line and near Kashitu station, midway between Broken Hill and Ndola. Building was commenced in August and completed in October, just before the commencement of the rains.

Messrs. Eminson and Dollman, who had been working on the Kafue River at Mwengwa, had just reported the discovery of Mutilla glossinae, Turner, a wasp parasitic on the pupae of G. morsitans and of considerable importance, since the former worker found that about 10 per cent, of the 350 pupae he had collected were destroyed by this insect. This is the first insect parasite of any tsetse to be found in numbers, and it was decided to let the future investigations centralise round it. In order to discover whether it was localised or generally distributed, a tour was made through the fly areas of N.E. Rhodesia during the dry season of last year (1915) for the collection of pupae in various localities. About 4,000 were collected and examined. May and July were spent at Chutika (Hargreaves) in the Luangwa Valley, part of August at Nawalia in the Mpika section of the same valley, and September at Ngoa on the plateau near Mpika. Breeding was found to have commenced in the Luangwa Valley about the middle of April, and by the time the plateau was reached it was at its height. Before dealing with the parasites found, some general questions will be discussed.