CHARACTERIZATION OF METARHIZIUM ANISOPLIAE ISOLATED FROM ORGANIC FARMS AND ITS EFFICACY AGAINST THE INSECT PESTS UNDER LABORATORY CONTROLLED CONDITION

Abstract

In agriculture, insect pests are one of the most constrictive aspects resulting in greater losses in crop quality and quantity if not treated promptly. So, focusing on numerous novel solutions for the management of insect pests that must be environmentally benign is of critical importance. As a result, the primary goal of the study was to characterize Metarhizium anisopliae and to investigate its insecticidal activity against insect pests in laboratory controlled conditions. Altogether, 60 soil samples were collected from randomly selected four organic farms of Basantatar, Khanar, Tarhara, and Buddhachowk, Nepal, and the isolates were isolated and conventionally identified to confirm that they were Metarhizium anisopliae. After then, the isolates SK13 & SC1 were confirmed as strains of Metarhizium anisopliae by molecular method 18S rRNA gene sequencing. The isolates were then bioassayed against S. frugiperda and Myzus persicae. For this objective, a conidial suspension of the isolates (1.76×10⁷spores/ml) was prepared and fed to the insects housed in disposable plastic glass by direct dipping the leaves of maize and beans before providing them to the relevant insect. Following the bioassay, In the case of S. frugiperda, isolates SK13 and SC1 had the same efficacy, however in the case of Myzus persicae; SK13 had a higher efficacy (91.79%) than isolate SC1 (86.66%). The results show that using this isolated fungus against insect pests will become an appealing alternative and a long-term solution for plant protection, resulting in decreased chemical pesticide exposures and automatically relieving our agricultural system of its detrimental consequences.