Bio-control of mosquito larvae Culex quinquefasciatus by using Bacillus sphaericus

Abstract

Mosquitoes acts as a vector for various kinds of diseases to public health worldwide. In India 99% of infection occurs when the mosquito Culex quinquefasciatus spreads a worm Wuchereria bancrofti that causes lymphatic filariasis through a mosquito bite. For many years’ mosquitoes were controlled based on spraying chemical insecticides to kill larvae and adults. The alternate, more effective ways of controlling them are environment friendly bio-insecticides. In the present study the bio insecticidal property of Bacillus sphaericus 3910 were tested against Culex quinquefasciatus at different larval stages with different concentration of the bacterial species. It was observed that 0.4 and 0.5g/100mL of the bacterial concentration was more effective against all 4 stages of the larvae. After the bioassay the bacterial protein was isolated and its molecular weight was identified. To determine the bio insecticidal property the bacterial protein was also isolated from the dead larvae treated with bio insecticide and the molecular weight was identified. Moreover, the plasmid DNA of Bacillus sphaericus was transformed to E. coli for broad spectrum of pathogenicity. Hence Bacillus sphaericus can be used as a bio control agent against the Culex quinquefasciatus larval population.