title: Efficacy of Bacillus sphaericus 2362 formulations against floodwater mosquitoes.
abstract: Four new formulations of Bacillus sphaericus 2362 yielded excellent control of floodwater mosquitoes Psorophora columbiae and Aedes nigromaculis in irrigated fields in Kings and Riverside counties of California. A primary powder formulation (ABG-6184) was the most active, producing excellent control of Ps. columbiae and Ae. nigromaculis at the rates of 0.05 to 0.5 lb/acre (0.055-0.56 kg/ha). A liquid formulation (BSP-2) was slightly less active, but was effective against the same species in the range of 1.0-1.5 lb/acre (1.12-1.68 kg/ha). Activity of the two corn cob granular formulations was largely dependent on potency (spores/gram). The high spore count granules (1.5 x 10(9) spores/gram) yielded 91 and 98% reduction of Ae. nigromaculis at the rates of 2.5 and 5.0 lb/acre (2.8 and 5.6 kg/ha), respectively. Against the same population, the lower spore count formulation (7.6 x 10(8) spores/gram) produced complete control at the rate of 10 lb/acre (11.2 kg/ha), but poor results were obtained at the rate of 5 lb/acre (5.6 kg/ha).
authors.affiliation: Department of Entomology, University of California, Riverside 92521.
authors.forename: M S
authors.initials: MS
authors.lastname: Mulla
authors.forename: H A
authors.initials: HA
authors.lastname: Darwazeh
authors.forename: N S
authors.initials: NS
authors.lastname: Tietze
mesh_terms: D000330:Aedes; D000818:Animals; D001407:Bacillus; D002140:California; D004190:Disasters; D009032:Mosquito Control