title: Differential effects of Bacillus sphaericus strain 2362 on Culex quinquefasciatus and its competitor Culex cinereus in West Africa.
abstract: The larval susceptibility to Bacillus sphaericus strain 2362 of the non-man-biting mosquito Culex cinereus and the urban filariasis vector Culex quinquefasciatus, two competitor mosquitoes in polluted habitats, was compared. In the laboratory, both species ingested a similar amount of B. sphaericus spores when fed c. 2 x 10(5) spores per ml for 30 min. However, in the same experiment, third-instar larvae of Cx quinquefasciatus were reduced by 98% at 24 h exposure while Cx cinereus larvae were only reduced by 6% at 72 h. In the field, preimaginal populations of Cx cinereus ingested, within a week, more than 99% of the applied spores, but showed no significant decrease through 14 days in cesspools treated at 10 g/m2 of a flowable concentrate of B. sphaericus 2362, containing 2 x 10(10) spores/g. It is proposed that specific biological control of Cx quinquefasciatus could result from appropriate treatment of breeding-sites with larvicidal B. sphaericus and competitive displacement by Cx cinereus or other mosquitoes with larvae that are more tolerant of B. sphaericus.
authors.affiliation: OCCGE/ORSTOM/Institut Pierre Richet, Bouaké, Ivory Coast.
authors.forename: L
authors.initials: L
authors.lastname: Nicolas
authors.forename: J
authors.initials: J
authors.lastname: Dossou-Yovo
mesh_terms: D000354:Africa, Western; D000818:Animals; D001407:Bacillus; D003465:Culex; D004605:Elephantiasis, Filarial / Q000635:transmission; D007303:Insect Vectors; D007814:Larva; D010572:Pest Control, Biological