Monitoring of carbamate resistance in Helicoverpa armigera (Hubner) population of central India

Carbamate resistance was monitored in H. armigera for six months during August 2000 to January 2001. Topical application of carbamate insecticides on mesothoracic region of H. armigera expressed moderate level of resistance: carbaryl (62.13 per cent), thiodicarb (63.18 per cent) and low level of resistance to methomyl (47.56 per cent). Carbaryl and methomyl resistance was increased up to 84.75 per cent (1.84-fold) and 81.25 per cent (2.60-fold) respectively in the sixth month (Dec. 2000) while thiodicarb resistance was at maximum (87.50 percent; 3.50-fold) in fourth month (Nov. 2000) of bioassay.