T. JAYA BHARGAVI*, K.V. HARI PRASAD, K. DEVAKI AND K. JYOTHSNA

Department of Entomology, S.V. Agricultural College, ANGRAU, Tirupati

ABSTRACT

Four native isolates of Bacillus thuringiensis Berliner viz., V13, CF24, CFo76 and W85 (collected from soils from in and around different locations from Tirupati, Chittoor Dt., Andhra Pradesh, India) were tested at five different concentrations against third instar larvae of Fall Army Worm Spodoptera frugiperda (J.E. Smith). Among the four native isolates tested, V13 isolate showed highest per cent larval mortality (86.66%), Lowest values of LC₅₀ (6.28 × 102 CFU/ml) and LT₅₀ (69.02 h) for third instar larvae of FAW, indicating that the isolate V13 could be used as a potent Bt native isolate for the management of third instar larvae of S. frugiperda.

KEYWORDS: Bacillus thuringiensis, LC50, LT50, Native isolates, per cent larval mortality, Spodoptera frugiperda