Toxicity of technical bifenthrin and malathion against the laboratory reared boll weevil, Anthonomus grandis (Boheman), were greater when topically applied in acetone to dorsum thorax than in solvent-emulsifier concentrate (EC) formulations in aqueous. Toxicity of bifenthrin (EC) formulation (in petroleum solvent) in Milli-Equivilant (MQ) water for dead category were significantly less than for dead + moribund category after 1 and 24 h in solution whether topically applied, tarsi were wiped in aqueous or in dry droplet. Topical application of malathion (in petroleum solvent) after 1 h in solution with MQ or domestic water showed poor toxicity.