author(s)
Anand Kumar ADVSLP, Rama Rao CV, Mallikharjuna Rao N, Krishnam Raju S and Nafeez Umar SK

abstract
Influence of certain insecticides viz., chlorpyriphos, profenophos, cypermethrin, deltamethrin, bifenthrin, lambda cyhalothrin and imidacloprid on growth and reproductive physiology of rice brown planthopper, Nilaparvata lugens (Stal) was investigated. Bifenthrin, cypermethrin, lambda cyhalothrin and deltamethrin resulted in enhancement of fecundity of brown planthopper (227.67, 218.33, 199.00 and 191.00 nymphs vs 131.00 nymphs in control) and consequently resurgence ratio ranged from 1.18 to 1.74. Application of chlorpyriphos, profenophos and imidacloprid on rice plants did not influence the reproductive rate of brown planthopper. Chlorpyriphos, cypermethrin, deltamethrin, bifenthrin and lambda cyhalothrin significantly increased the nymphal survival (86.67 per cent to 96.00 per cent against 80.67 per cent in control) and growth index (6.34 to 7.11 vs 5.63 in control). Cypermethrin, deltamethrin, bifenthrin and lambda cyhalothrin resulted in a sex ratio in favour of more number of females.