Diversity of entomopathogenic fungi across Agro-climatic zones of Karnataka, India

Abstract

Entomopathogenic fungi are the most versatile and potential biocontrol agents, due to their adaptability, mode of entry, persistent nature and wide host range. The present study aimed to isolate and identify the native entomopathogenic fungi for the biocontrol of major sucking insect pests of floriculture. Eighty-one fungal isolates were isolated from 55 soil samples and 26 infected insect cadavers were collected from the eastern and southern dry zones of Karnataka, India. Serial dilution and plating techniques, and inseet bait techniques were followed. The insecticidal activity of fungal isolates against aphids, mites, 2nd instar larvae of thrips and whitefly nymphs was determined by leaf disc bioassay under in vitro conditions. The results of the experiment revealed that among 81 fungal isolates, sixteen (19.25%) exhibited insecticidal activity against test insects and further, a distribution study revealed that 50 per cent of EPF isolates were belonging to genera Beauveria and Metarhizium (25% each), 18:75% Aspergillus, 12.50% were Lecanicillium spp. and 13% were Paecilomyces spp. (6.25%) and Hirsutella spp. (6.25%) respectively. It was concluded that the recovery rate of EPF is lower with 19.5% and the dominant genera of EPFs are Beauveria and Metarhizium. This show EPFs with broader host rage will have more chances of survival and the same criteria can be used for the selection of efficient EPFs.