Screening of endophytic isolates of Metarhizium anisopliae (Metchnikoff) Vuillemin and Beauveria bassiana (Balsamo) against P. xylostella linnaeus

An experiment was conducted to discover the promising endophytic fungal isolates against the target pest, diamondback moth, Plutella xylostella using the larval dip method in a laboratory bioassay at Biological Control Research Laboratory, ICAR Unit-9, Anand Agricultural University, Anand (Gujarat). We tested five of each species, M. anisopliae, and B. bassiana, isolated from diverse soil and insect hosts from distinct geographical locations in Gujarat against P. xylostella larvae in their second and third instars. With a high mortality rate of 89.97 and 86.96, AAUBC Bb-5a and AAUBC Ma-26 were the two promising isolates chosen for second-instar larvae, showing a high mortality rate. This was corroborated by data on third-instar larvae, with 86.95 and 79.95 percent mortality for AAUBC Bb-5a and AAUBC Ma-26, respectively which was a somewhat reduced mortality rate when paralleled with second-instar larvae. The results of dosage mortality experiments at different concentrations showed that M. anisopliae AAUBC Ma-26 had a larger LC₅₀ value of 2.8×10⁶ and 1.2×10⁷ in the second and third instars, respectively. In comparison B. bassiana isolates, AAUBC Bb-5a had lower LC₅₀ values of 1.1×10⁶ and 2.1×10⁶ in their second and third instars, respectively.