Efficacy of different concentration of Metarhizium anisopliae (Metsch.) Sorokin against white grub at lab condition in Chitwan, Nepal

Abstract

An experiment was conducted to evaluate the effect of different concentration of entomopathogenic fungus, Metarhizium anisopliae (Metsch.) Sorokin against white grubs in the Entomology Laboratory, at Institute of Agriculture and Animal Science, Rampur, Chitwan in 2015. For the experiment, 6 treatments were tested against white grubs at the rate of 107 commercial conidial spores per ml and indigenous 107, 105, 104, 102 of conidial spores per ml including control and each treatment were replicated thrice. Total 270 grubs were treated, with 15 grubs in each replication of each treatment. They were screened for relative pathogenicity, and the mean lethal time eliciting 50% mortality (LT50) was calculated. Indigenous 104 spores/ml concentration of fungus had the lowest LT50 value of 61.45 days followed by 102 spores/ml with 65.35, 107 spores/ml with 68.98, 105 spores/ml with 76.04 and commercial 107 spores/ml with 152.71 days. Indigenous isolate showed higher mortality of white grubs in comparison to commercial isolate