Development of a model for Simulium damnosum s.l. recolonization dynamics at a breeding site in the onchocerciasis control programme area when control is interrupted.
Problems associated with the population dynamics and control of Simulium damnosum Theo. s.l. are discussed in relation to the programme for the control of onchocerciasis (caused by Onchocerca volvulus) in the Volta River Basin, West Africa. Nulliparous and parous biting rates were observed during the recolonisation of the Grechan rapids when applications to control the larvae were suspended for 3 months during the dry season [see RAE/B 69, 2672]. A new method of data analysis is proposed and used to estimate population parameters. A new mathematical model of recolonisation is proposed that mimics the key features of the process. The model is used to simulate the effect of larvicides and could form the basis for an investigation of alternative management strategies.