Mise en évidence d'une résistance au téméphos dans le complexe Simulium damnosum [S. sanctipauli et S. soubrense] en Côte d'ivoire

Résumé Fr En

Des espèces du complexe S. damnosum ont pu, en zone de forêt et dans certaines conditions d’isolement, développer rapidement une sérieuse résistance au téméphos. Cette résistance semble se manifester davantage chez S. sanctipauli que chez S. soubrense.

In Ivory Coast, on the lower Bandama River, in forest area, larvae of the Simulium damnosum complex have rapidly developed a serions resistance to temephos (abate (R)). The resistance ratio to the LC 99,9 level can reach 45. This resistance seems to be more apparent in S. sanctipauli. We have noted for this species a high frequency of a heterozygote inversion on the chromosome III L in resistant larvae. Treatments fait completely at dosage 4 to 8 times the normal operational dosage (0,05 mg/l during 10 mn). The resistance occurs on a very limited portion of the river, 65 km long and limited upstream by a dam and downstream by the absence of breeding sites in the final 90 km of the river. The resistant population is currently being controlled with chlorphoxim, an alternative insecticide.