Department of Entomology and Agricultural Zoology, Institute of Agric. Sci., Banaras Hindu University, Varanasi-221 005, India.
* Present Address: AICRP on Pesticide Residues, Department of Soil Science, College of Agriculture, OUAT, Bhubaneshwar-751 003, India.
The inheritance of resistance to cypermethrin. fenvalerate. quinalphos and endosulfan in Helicoverpa armigera through generations in laboratory conditions in resistant and susceptible populations collected from differert host plants indicated that maximum dilution of resistance occurs between F3 to F4 generations in both the cases. Further breeding results in production of sterile eggs which is an indication of mixing up of resistant and susceptible genotypes in nature at various times through various causes and this is not acquired in nature to maintain this character. However dilution of resistant is much quicker in resistant strains than susceptible ones. Rate of resistance dilution in the laboratory and in field condition is somewhat comparable except the second peak in March for which among different reasons wider breeding through migration from distant places causing heterogeneity seems to be more convinceable.
