Entomological surveillance of bluetongue in France in 2002.

Bluetongue (BT) is an arboviral disease that appeared in the Mediterranean in 1998. In France, the principal vector, Culicoides imicola, was detected for the first time in Corsica in October 2000, a few weeks before outbreaks of BT virus serotype 2 (BTV-2). Entomological surveillance was implemented in Corsica and on mainland France in 2002. In Corsica, the aim was to study the population dynamics of C. imicola and other potential vectors. On the coastal mainland, the objective was to survey the introduction of C. imicola. One-night catches per site were performed every three weeks at 12 sites on Corsica and every month at 19 sites on the mainland. In Corsica, 84,790 Culicoides belonging to 50 species were collected over 180 nights. C. imicola accounted for 18.3% of the total captured. On the mainland, 16,197 Culicoides (44 species over 109 nights) were collected, none of which were C. imicola. The geographic and seasonal distribution of C. imicola and other species of interest are discussed in relation with their bio-ecology and environment. These datasets are essential for a better understanding of the epidemiology of BT, and to create and validate predictive models based on remote sensing in order to identify areas at risk for BT.