Vol. 8, Issue 12, Part F (2024)

Entomopathogenic fungi are valuable weapons for bio control and play an important role in integrated pest management. Beauveria bassiana has been known as a potential entomopathogenic fungus. Bio efficacy of Beauveria bassiana products (Green Beauveria, Multiplex Baba and WAH each of which contains 2 x 10⁸ conidia ml^-1) with five different doses i.e., 1ml 100^-1ml, 2 ml 100^-1ml, 3ml 100^-1ml, 4ml 100^-1ml and 0 ml 100^-1ml of each product, were tested against first, second, third, and fourth instar larvae of Spodoptera litura on cabbage in laboratory conditions. All the concentrations showed significantly better results than the control, but the maximum mortality percentage was obtained at the highest concentration of each product. The results obtained show that Green Beauveria and WAH was effective against first-instar larvae with 86.7% larval mortality, and WAH was most effective against second-instar larvae with 96.67% larval mortality after 14 days of treatment. Further, LC₅₀ and LT₅₀ values were also evaluated, which revealed that WAH was found to be most effective against first-instar larvae, whereas Multiplex Baba against second and third-instar larvae with LC₅₀ value of 3 x 10⁸ conidia ml^-1, 1.4 x 10⁸ conidia ml^-1 and 9 x10⁸ conidia ml^-1 respectively. However, fungal formulations were least effective against fourth-instar larvae. LT₅₀ values of first and second instar larvae when treated with WAH and Multiplex Baba was 69.6 hours and 144 hours, respectively. Thus, the present findings revealed that the efficacy of Beauveria bassiana was quite promising in early larval instars of Spodoptera litura.