BLACKFLY CONTROL USING GROUND LARVICIDING - PRESENT STATUS AND PROSPECTS WITH SPECIAL REFERENCES TO THE ONCHOCERCIASIS CONTROL PROGRAM IN WEST-AFRICA

The control of blackfly is based on larvicide spraying in rivers where the insects breed and their larval stages are vulnerable. The first t echnique for large-scale operations, consists of using aircraft in the same way as for mosquito control and crop protection operations. The second technique, which will be discussed in this paper, consists of g round treatment of rivers, either directly with a container or with a spraying pump or by boat spraying insecticide in cross strip. In areas of West Africa where onchocerciasis is still prevalent, ground treatm ent is done to support aerial operations and to a lesser extent to con trol nuisance in areas where the endemicity of the disease is low. In onchocerciasis-freed zones, control of blackfly aims only at suppressi ng the nuisance in order to enhance the socio-economic development in areas at unfair disadvantage. This distinction is important for determ ining the responsibilities of various groups. Vector control to interr upt the transmission of onchocerciasis is the mandate of OCP while the control of nuisance is the responsibility, depending on the circumsta nces, of the private sector, the government and/or village communities . In this paper, we have attempted to highlight the objectives of such treatments, the responsibilities of various groups and the prospects in West African countries located in the Onchocerciasis Control Progra mme area. We also present the situation of ground larviciding in count ries outside the Programme, in temperate as well as tropical condition s, in order to provide some basis for the development of ground treatm ent strategies in the OCP area.