Density and dispersal of the loaiasis vector Chrysops dimidiata in southern Cameroon

By mark-release-recapture experiments, we assessed the density of loaisis vectors, Chrysops dimidiata Wulp plus some Chrysops silacea Austen (Diptera: Tabanidae) and estimated their range of flight in the secondary forest of southern Cameroon. In 1993, the release point was at the centre of the study area and recapture points were at 1100 m radius. In 1994, releases were on the periphery of the study area and recapture sites were 400-8000m from the release points. Results were concordant and showed Chrysops female densities of 785-3682 flies/km2. The theoretical flight range was < 6000m, with a maximum distance of 4500m observed. These results are considered promising for the use of vector control methods against loaiasis.