Estimation of Level of Resistance of Chemical Insecticides, Biopesticides, and Botanicals against Rice Weevil (Sitophilus oryzae) Across Multiple Progenies
Anamika Kumari *
Department of Entomology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (U.P.), India.
Usha Yadav
Department of Entomology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (U.P.), India.
*Author to whom correspondence should be addressed.
Abstract
The rice weevil, Sitophilus oryzae is a major pest of stored grains, necessitating effective control strategies. This study evaluated the efficacy of chemical insecticides, biopesticides, and botanicals across four progeny generations of S. oryzae at laboratory of department of Entomology, Sam Higginbottom University of Agriculture Technology and Sciences, Prayagraj, India. Mortality rates, lethal concentrations (LC50/LC90), dose-response slopes, and relative potency were analyzed at 24, 48, and 72 hours after treatment (HAT). Synthetic insecticides (Emamectin benzoate, Deltamethrin, Spinosad) demonstrated superior efficacy with LC50 ≤2.5 ppm, while biopesticides (Beauveria bassiana, Verticillium lecani) and botanicals (Custard apple powder, Eucalyptus) required higher doses. Time-dependent efficacy improvements and resistance patterns were observed across progenies. Results highlight the potential of integrating synthetics with bio-botanical alternatives for sustainable pest management.
Keywords: Concentrations, dose response, lethal, progeny, resistance, stored grain pests, time dependent