Comparative efficacy of different concentrations of Withania somnifera, Pongamia pinnata and Azadirachta indica against Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) in wheat grains

In present study, bioassay of leaf powder of Withania somnifera, Pongamia pinnata and Azadirachta indica was done against T. putrescentiae in wheat grains. All the concentrations (0.5%, 0.6%, 0.7%, 1% and 2%) of all the three botanical powders were significantly better than the control (untreated wheat grains) except 0.5 percent concentration of P. pinnata. Among the botanicals, W. somnifera and A. indica at 0.7 percent concentration showed comparable mite population of 39.05 and 40.05 mites, respectively after 45 days as compared to 161.89 mites in untreated wheat grains. Protection against T. putrescentiae was 15.9 to 100, 45.7 to 100 and 33.9 to 100 percent with A. indica leaf powder, 2.3 to 100, 8.2 to 100 and 9.8 to 100 percent with P. pinnata leaf powder and 28.4 to 100, 43.7 to 100 and 22.1to 100 percent population reduction with W. somnifera leaf powder after 15, 30 and 45 days post-treatment at various concentrations.