[Evaluation of the efficacy of Bacillus sphaericus Neid 1904 applied to previously cleaned gutters for Culex quinquefasciatus Say 1823 control in Abidjan (Côte d'Ivoire)].

In the framework of a pluri-institutional research project, led in Abidjan and aimed at defining measures to fight against mosquitoes in Abidjan area, a test to struggle for C. quinquefasciatus larvae was carried out in 1990. This test was conducted in Koumassi, which is one of Abidjan district, in which environmental conditions are very favourable for developing C. quinquefasciatus non-adult stages. The test consisted essentially in spreading a Bacillus sphaericus waterish solution (dose: 10 g.m-2) in previously cleaned gutters. The efficiency of the fight test was essentially assessed through: -the size of C. quinquefasciatus non-adult stages populations according to their development stage (egg, larva, nymph); -variations of both, C. quinquefasciatus females aggressive density and their physiological age. The gutters cleaning did not reduce significantly C. quinquefasciatus non-adult stages populations. On the other hand, the effectiveness of B. sphaericus was convincing. Its effects were tested to last for four weeks. The results were confirmed by the observations made on C. quinquefasciatus adult populations.