Potential of Local Isolates of Entomopathogenic Fungi Metarhizium sp. and Beauveria sp. on Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae) Larvae

Abstract

Spodoptera frugiperda is an important pest which is an invasive insect that attacks maize plants. One alternative control that can be used is entomopathogenic fungi. The aim of this study was to analyze the potency of local isolates and flour formulations of the entomopathogenic fungi Metarhizium sp. and Beauveria sp. against S. frugiperda larvae in maize. This study used randomized block design (RBD) which consisted of five treatments (control, local isolates of the entomopathogenic fungi Metarhizium sp. and Beauveria sp., and flour formulations of the entomopathogenic fungi Metarhizium sp. and Beauveria sp. that comes from a pesticide shop) which was held from September 2021 until January 2022 in screen house and Laboratory of Plant Pest and Disease, Faculty of Agriculture, University of Sumatera Utara at an altutide of ±25 mdpl. Each treatment used a spores density of 10⁸ spores/ml/ FAW’s larvae with five replications.
The results showed that the highest larvae mortality (96,00%) was found on local isolate of Beauveria sp. The symptoms of infection with Beauveria sp. were the body of the larvae of S. frugiperda overgrown with white fungal colonies and infection with Metarhizium sp. were the body of the larvae of S. frugiperda overgrown with green or dark brown fungal colonies. The shortest lethal time (LT₅₀) (4,75 days) was found on local isolates of Beauveria sp and the longest one (5,65 days) was found on flour formulations of Metarhizium sp. The highest attack intensity (56,40%) was found on flour formulations of Metarhizium sp. while the lowest one (28,40%) was found on local isolate of Beauveria sp.