Mosquito larvicidal and pupicidal activity of Euphorbia hirta Linn. (Family: Euphorbiaceae) and Bacillus sphaericus against Anopheles stephensi Liston. (Diptera: Culicidae)

ObjectiveTo explore the larvicidal and pupicidal activity of Euphorbia hirta (E. hirta) leaf extract and Bacillus sphaericus (B. sphaericus) against the malarial vector, Anopheles stephensi (An. stephensi).MethodsThe larvicidal and pupicidal activity was assayed against An. stephensi at various concentrations ranging from (75-375 ppm) under the laboratory as well as field conditions. The LC50 and LC90 value of the E. hirta leaf extract was determined by probit analysis.ResultsThe plant extract showed larvicidal effects after 24 h of exposure; however, the highest larval mortality was found in the methanol extract of E. hirta against the first to fourth instars larvae and pupae of values LC50= 137.40, 172.65, 217.81, 269.37 and 332.39 ppm; B. sphaericus against the first to fourth instars larvae and pupae of values LC50= 44.29, 55.83, 68.51, 82.19 and 95.55 ppm, respectively. Moreover, combined treatment of values of LC50= 79.13, 80.42, 86.01, 93.00 and 98.12 ppm, respectively. No mortality was observed in the control.ConclusionsThese results suggest methanol leaf extracts of E. hirta and B. sphaericus have potential to be used as an ideal eco-friendly approach for the control of the malarial vector, An. stephensi as target species of vector control programs. This study provides the first report on the combined mosquito larvicidal and pupicidal activity of this plant crude extract and bacterial toxin against An. stephensi mosquitoes.