Kumasi is a rapidly expanding township of about 80,000 inhabitants. This has led to an extensive building programme which has followed the ridges in the vicinity of the town, leaving the valleys in between potentially dangerous isolated habitats of Glossina. The danger from these isolated habitats is enhanced by the large numbers of itinerant labourers.

The topography of the town and its surroundings is hilly; the vegetation is of semi-deciduous rain forest type, but with very thick secondary bush along most of the valleys in which the farms had been abandoned.

The climate is remarkably equable with the rainfall showing periodicity but the percentage relative humidity is high and even throughout the year.

The experimental clearing of an isolated habitat of Glossina in the Dechem valley was commenced in July 1950 and finished in March 1951. The clearing was of a discriminative nature, with cutting, stumping and burning of a strip of bush up to 20 ft. high and 250–300 yards wide along the stream, and a high reduction of fly population was achieved. This reduction was such that further clearings were planned.

The reduction in fly population was assessed from fly-boy catches and from trap catches. These records showed that rainfall affected the catches.

At the time of writing, about a sixth of the protective clearings planned around Kumasi have been completed, the fly population being reduced between about 80 per cent. and complete eradication.