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

By mark-release-recapture experiments, we assessed the density of loaisis v ectors, 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 stud y area and recapture points were at 1100 m radius. In 1994, releases were o n the periphery of the study area and recapture sites were 400-8000 m from the release points. Results were concordant and showed Chrysops female dens ities of 785-3682 flies/km(2). The theoretical flight range was < 6000 m, w ith a maximum distance of 4500 m observed. These results are considered pro mising for the use of vector control methods against loaiasis.