Asian Journal of Biotechnology and Genetic Engineering

Aim: This study was aimed to investigate the larvicidal potential of the conidia suspension of Aspergillus flavus against Anopheles mosquitoes.

Methods: Aspergillus flavus was isolated from soil using soil suspension procedures and was identified using morphological characteristics. Bioassay was performed to determine the efficacy of Aspergillus flavus conidial suspension against early 4^th instar larvae of Anopheles mosquito using WHO-2005 protocol with slight modifications.

Results: Four different concentrations of conidial suspension; 3.3×10⁶, 3.3×10⁵, 3.3×10⁴ and 3.3×10³conidia/ml were tested, and the results showed that; mortality increases with the increase in conidial concentrations and exposure time. The lowest mortality (12%) was recorded at 3.3×10³ conidia/mL and 24-hours post exposure whereas the highest mortality (78%) was recorded at 3.3×10⁶ conidia/mL and 72-hours post exposure. LC 50% and 90% for the larvae was found to be 1.6×10⁸ and 4.2×10⁹conidia/mL at 24-hours; 2.0×10⁴ and4.0×10⁵ conidia/mL at 48-hours; 1.3×10³ and 3.2×10⁴ conidia/mL at 72-hours.

Conclusion: These results indicated that Aspergillis flavus conidia suspension are pathogenic to immature stage of Anopheles mosquito and could be suggested as a biological control for mosquito management.