Evaluation of Biocontrol Potential of Metarhizium anisopliae Strains Against Larvae and Adults of Aedes eegypti (l.)

Abstract

In the present study, we exposed larvae and adult females of Aedes aegypti (L.) to fungal suspensions of three virulent strains of Metarhizium anisopliae (Metsch.), viz., M34412, M34311 and M81123. The strains resulted in 7 to 37% survival as a result of fungal infection over the 8 d test period in case of adults and 2 to 90% survival for larvae. Mean survival period varied between 3 and 4 d for treated adults, whilst control survival exceeded 28 d. Values of LC₅₀ varied from 5.92í—10³ conidia/ml for M34412, 3.49í—10⁴ conidia/ml for M34311 and 5.12í—10⁵ conidia/ml for M81123. Based on virulence and stability, the most promising strain, M. anisopliae M34412 was used for lethal exposure time determination. An exposure time of only 4 h was necessary to cause 50% mortality. Supplementation with M. verrucaria chitinase enzyme increased the larval mortality at lower conidial concentrations.