Synergistic Effect of Entomopathogenic Fungi and Bacteria against Pulse Beetle, Callosobruchus chinensis

Callosobruchus chinensis is one of the most destructive insect pests of Cicer arietinum (Chickpea) in storages and renders grains unfit for human consumption. In the present study, synergistic effects of entomopathogenic fungi (EPF), Beauveria bassiana and Metarhizium anisopliae and entomopathogenic bacteria (EPB), Photorhabdus temperata and Xenorhabdus nematophila were studied as bio-control agents to manage this pest. In addition, percent conidial germination and % mortality of C. chinensis were also evaluated when B. bassiana was used with DEBBM. The minimum number of eggs (0.66 grain^-1), number of holes (1 grain^-1), number of F₁ new emerged (5.6 jar^-1), days to 100 percent mortality F₁ (3), weight loss (4%), damage (5%) whereas the maximum inhibition rate of 85% and percent mortality of C. chinensis were observed in synergistic concentration of EPB as compared to EPF. Synergistic concentration (1×10⁸) of bacteria gave the best results against C. chinensis as compared to that of entomopathogenic fungi. The maximum percent conidial germination (90%) of B. bassiana and percent mortality (50.40±2.20a), (79.70±0.28a) and (90.76±0.56a) of C. chinensis were observed when DEBBM was synergized with B. bassiana after seven, fourteen and twenty one days, respectively.