Larvicidal potential of fungi isolated from larval mosquito habitats against Aedes aegypti

Forty-six water and soil samples were collected from various larval mosquito habitats of four districts of Madhya Pradesh for isolation of fungal pathogens against Aedes aegypti. Five fungal isolates, namely, Beauveria bassiana, B. nivea, Myrothecium roridum, Aspergillus flavus and Trichoderma harzianum, were found to have potential against the third instar larvae. Larvae of A. aegypti were found to be more susceptible to B. nivea (LD₅₀ value of 1.2 x10⁵ conidia ml⁻¹). M. roridum yielded lowest LC₅₀ value (67.61 μl ml⁻¹) of extracellular metabolite, which was followed by A. flavus (107.15μl ml⁻¹). Highest LC₅₀ value (631.0μl ml⁻¹) was obtained for T. harzianum. In case of M. roridum, larval mortality occurred due to toxic metabolites present in the sporodochia.