Pathogenicity of entomopathogenic fungi Metarhizium anisopliae to white grubs Holotrichia serrata

Abstract

Holotrichia serrata species of white grub is one of the major pests in sugarcane causing severe damage to kharif crops by its larval stages which lives inside the soil and causes quantifiable losses in the crops. Their infestation has been reported across the country and incidence is increasing every year. Current suppression strategy is mainly strategized with the use of chemical pesticides; however, none of them are found effective by farmers in lowering down their population below ETL. The biological factors that influence populations of white grubs’ complex are relevant to the potentiality of the biological control with soil fungi. Metarhizium anisopliae is an entomopathogenic fungus that occurs naturally in soils and causes disease in various insect pests. Laboratory assays were done to measure the pathogenicity of M. anisopliae against H. serrata. M. anisopliae identified as pathogenic for eggs to adult stage of test insect pest at higher dose 1010 spores/ml. The result showed that higher doses achieving greater killing in eggs and much effective for 1st and 2nd instar grub, pupal and adult stage after 20 days of treatment; however it is not recorded to be effective against 3rd instar of grub at this doze.