Effect of the entomopathogenic fungus Metarhizium anisopliae against Mosquitos (Aedes aegypti) in vitro conditions

Entomopathogenic fungi are promising new biological tool for the control of pests and pose no risk to man and non-targeted organisms. Isolation and identification of native entomopathogenic fungi in a field is necessary for the successful control of pest in a particular region. Experiment was conducted to evaluate the occurrence of entomopathogenic fungi from different soil and their efficacy in the control of mosquitos. Using rain beetle, the fungi were isolated by insect baiting method using PDA. Morphological identification of the isolated fungi showed Metarhizium anisopliae. The result of the study showed a variation in the occurrence of the Metarhizium anisopliae at the three locations. The pathogenicity of the isolated fungi was tested on Aedes eagyptii larvae in three different concentrations (1.8.103, 3.6.103 and 4.5.103 conidia/ml). The result showed a progressive increased in larval mortality with an increased number of days. The mortality varied from 4 to 100%. Rapid larval mortality was observed two days after spraying, mortality was highest and relatively uniform at higher concentration. No mortality was observed in the control treatments. The test showed LC50 value of 14.5.103, 12.9.103, 1.4.103, 0.4.103, 0.4.103 and 0.1.103 conidia/ml after exposure for 1, 2, 3, 4, 5, and 6 days respectively. The outcome of this research showed variation in the diversity of entomopathogenic fungi in different soil location. Metarhizium anisopliae look promising in the control of the Aedes eagyptii mosquito larvae and should be tested in the field, or this could be the starting point for a genetic experiment.