Bacillus amyloliquefaciens: A mosquitocidal bacterium from mangrove forests of Andaman & Nicobar islands, India

Samples collected from the mangrove forests of Andaman & Nicobar islands yielded a mosquitocidal bacterium, whose extracellular metabolite(s) exhibited mosquito larvicidal and pupicidal activity. The bacterium was isolated using standard microbiological methods and identified using classical biochemical tests and rpoB gene sequences. The mosquitocidal bacterium was identified as Bacillus amyloliquefaciens. Mosquitocidal metabolite(s) was separated from the culture supernatant of the bacterium and its efficacy against the larval and pupal stages of different species of mosquitoes was determined in terms of LC50 and LC90. Mosquito larvicidal activity in terms of LC50 against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti was respectively, 26.4 μg, 22.2 μg and 20.5 μg/ml and its pupicidal activity was 4.4 μg, 8.2 μg and 14.5 μg/ml respectively. The mosquitocidal metabolite(s) was found to be a biosurfactant. This is the first report of the mosquitocidal activity of B. amyloliquefaciens and it is a new weapon which can be added to the array of microbial agents for use against mosquitoes.