Evaluation of beauveria bassiana and metarhizium anisopliae isolates against plutella xylostella (L.) under laboratory conditions

Abstract

Twenty isolates each of Beauveria bassiana and Metarhizium anisopliae were tested against the second instar larvae of Plutella xylostella through laboratory bioassay using larval dip method at the concentration of 1 x107 conidia/ml. Higher larval mortality of 88.85% and 81.44%, were observed with NBAIR Ma-4 and NBAIR Ma-35 isolates of M. anisopliae and 77.36% with NBAIR-Bb-5a isolate of B. bassiana. Further studies on dose and time mortality with four isolates indicated lowest LC50 value of 2.6x104 conidia/ml and LT50 of 86.6 hours with NBAIR Ma-35 isolate. These isolates have to be further tested against P xylostella in infested fields of cabbage and cauliflower.