The use of entomopathogen is a feasible substitute for insect control because of their virtual specificity and lower environmental impact. The search for microbial strains against Dipterans could have an impact on mosquito control programs. Bacterial pathogens are ubiquitous in soil and water. The potential for bacteria to play a role as pathogen of vectors is an important step towards ecosafe management of vectors. In the present investigation soil bacterial fauna were isolated to assess their insecticidal activities against Anopheles stephensi (L) larvae. The isolated bacterial colonies from soil were characterized according to morphological, physiological and biochemical parameters. High larvicidal activity was observed by three strains of bacillus i.e. Bacillus polymyxa, Bacillus cerus and Bacillus subtilis amongst all the identified strains. Further Bacillus subtilis strain IF5 (NCBI: KJ022639 ) displaying the highest activity stood first against both the second and fourth larval instar larvae with LC50 of 1.865 and 3.361x6.5x107 cfu/ml respectively followed by B. cerus and B. Polymyxa (LC50 2.931 and 4.305 & LC50 of 4.776 and 5.403 x6.5x107 cfu/ml ). Second instar larvae were more susceptible than fourth instar for all the bacterial isolates. These findings are a valuable tool for the control of mosquitoes of medical importance, B. subtilis strain IF5 can be recommended for industrial production of bacterial preparations. Further work is required to assess the epidemiological impact of this finding.
