Bioecology of three main Culicoides Latreille species (Ceratopogonidae), vectors of equine and ruminant virus in Senegal

Several species of Culicoides Latreille are involved in the transmission of virus-es and nematodes in the Afrotropical Region. Vector-borne diseases caused by viruses transmitted by Culicoides biting midges have a renewed interest in West Africa, due to recent major outbreaks, including African Horse Sickness in Senegal in 2007, causing a fi nancial loss estimated at €1.37 million. Although of major economic importance, the bioecology of Culicoides species still needs to be explored. The aim of this study was to use innovative ecological approaches for describing the trophic behaviour of C. kingi Austen, C. imicola Kieffer and C. oxystoma Kieffer, as well as their larval habitats in equine environments of the Niayes area, Senegal. These Culicoides species are vectors of internati-onally important viruses of livestock and equids. Firstly , blood meal source in these Culicoides species were identifi ed. A correlation was then made between blood meal source (identifi ed in engorged Culicoides females collected in a suction light trap) and the available vertebrate hosts along four concentric rings (200, 500, 1,000 and 2,000 m) centred at the trap site, to determine the foraging range of the three vector species. Finally, the larval habitats and spatial tempo-ral dynamics of immature populations of these species were studied. This work completes the corpus of bioecological knowledge of Culicoides in the Niayes area of Senegal and proposes research needs to better control the immature and adult populations of vector species in order to better anticipate and prevent Culicoides-borne disease outbreaks