Entomocidal, repellent, antifeedent and growth nhibition efects of different plant extracts against Tribolium castaneum (Herbst) (Tenebrionidae: Coleoptera)

In present investigation, toxic, repellent, antifeedent and growth inhibition effects of five different plant extracts: Melia azedarach, Pegnum hermala, Salsola baryosma, Azadirachta indica and Zingiber officinale, were evaluated on different life stages of T. castaneum. The highest mortality (10.14%) was observed with A. indica and the minimum mortality (0.67%) was invoked by Z. officinale treatment. Similarly, A. indica showed highest repellent effect compared to rest of the plants. Feeding deterrence was highest (90.15%) with S. baryosma treatment, followed by P. hermala (84.85%), M. azedarach (80.19%), A. indica (73.48%) and Z. officinale (57.58%). The extracts inhibited the growth of T. castaneum. Inthe case of A. indica, the lowest numbers of larvae (32.67), pupae (16.33) and adults (11.33) emerged at 15% concentration, while the highest emergence of larvae (80.33), pupae (75.00) and adult (71.00) were observed for Z. officinale. The other three plant extracts had moderate regrowth inhibition on the beetle. Overall, A. indica extract was found to be the most effective while, Z. officinale extract was least effective against the beetle. This study can be very helpful in future when the use of plant extracts become common and available to the farmers as an alternative to synthetic pesticides.