Infectivity of entomopathogenic fungal bio-agents on yellow mite, Polyphagotarsonemus latus Banks of jute

Abstract

Yellow mite is a serious pest of many field and horticultural crops including jute. As repeated use of acaricides possess problem of resistance, alternatively, the infectivity of talc based formulation of three entomopathogens, i.e., Lecanicillium lecanii (Ll), Isaria fumosorosea (= Paecilomyces fumosoroseus ) (Pf) and Beauveria bassiana (Bb) at 4x10 8 cfu/ml, and 6x10 8 cfu/ml concentrations were evaluated against yellow mite under laboratory condition. In both the concentrations, Pf and Bb recorded significantly higher mortality of yellow mite than Ll. At 3-DPT (days post treatment) significantly highest mortality was observed in Pf (30.35%) followed by Bb (21.59%) and Ll (4.87%). Later on at 4 and 5-DPT period the level of mortality in Pf and Bb treated population was at par but significantly higher than Ll. At 5-DPT, Pf recorded maximum cumulative mortality (40.92%) at par with Bb (35.99%) and significantly higher than Ll (12.92%). Significantly higher cumulative mortality at 6x10 8 CFU/l concentration during 5 days after treatment was 34.35%. The infectivity of talc based formulation of Ll at both the concentrations was significantly less than Pf and Bb. Higher infectivity of I. fumosorosea indicates it to be ideal for yellow mite control in jute.