Resistance to Phosphine In Rice Weevil <i>Sitophilus oryzae</i> (L.) from South India

Rice weevil Sitophilus oryzae (L.) is one of most serious insect pests stored grains. Management this thus vital and fumigation with phosphine gas the common method. However, overreliance on has resulted in development heritable resistance S. oryzae. The detection frequency distribution crucial for management strategy. This study assesses frequency, strength populations from four southern states India viz., Tamil Nadu, Kerala, Andhra Pradesh Telangana. bioassay results revealed that all these survived at both discriminating concentrations 0.04 0.25 mg/ l. There were no susceptible weak resistant populations, exhibited varied strong ranging 13.33 to 80.90%. Pudukottai (80.90%) recorded high followed by Trichy (68.97%) Tirunelveli (67.82%) ones; Thiruvarur lowest (13.33%). indicated was prevalence individuals prevalent across sampled regions.