Entomological aspects of African onchocerciasis and observations on Simulium in the Sudan.

Following a review of the literature on Simuliidae, relevant to the African scene, since 1955, the authors present observations made on Simulium damnosum at Mvolo, Equatoria, and along the Damer reach of the Nile, in the Sudan and consider these in relation to the economic importance of this species and the possibilities for control of the fly and of onchocerciasis transmitted by it.Meta-diethyltoluamide has been shown to be an effective repellent against this species, and the authors suggest that this or some other modern insect repellent might usefully be made available locally.It is suggested that the full life-cycle of S. damnosum in this area needs to be worked out, and a study made of the long-term effects of DDT larviciding on the flora and fauna of a typical river. A procedure for larviciding is recommended. Attention is drawn to the possibility of achieving natural control.