International Journal of Entomology Research

Authors
Sudhakar Gupta, Harpreet Singh, Monika Gupta

Abstract
The immature stages of P. fuscipes reared on T. granarium, which was treated with 1% and 5% ethanol leaf extract of C. roseus revealed a decline in their survival (l_x) in comparison to controls. Similarly, the highest mortality (32.2%) was recorded in the L₂ stage followed by egg (26%). The life expectancy (e_x values) were also identical to those of controls and in this case too, the values declined from 2.70 days in eggs to 0.5 days in case of adults. The dry weights of individuals treated with 1% ethanol extract, declined only in adults (0.66 mg ; P/_0.05) that is significantly lower than those of controls. In case of 5% treatment however significantly lower dry weights were recorded in L₂ (0.28 mg; P/_0.05), pupae (0.52 mg; P/_0.01) and adult (0.50 mg; P/_0.01) vis-e-vis controls. The growth-rate increased up to pupae at 1% treatment and L₂ at 5% treatment, beyond which it declined and became negative in adults. A negative growth rate in adults occurred on account of minimal feeding. The egg laying observed was significantly lower in P. fuscipes reared on T. granarium treated with 5% ethanol leaf extract (8^th day=02.33, 10^th day=1.66 and 12^th day=1.00; P/_0.01) in comparison to controls and no eggs were recorded on the 14^th and 16^th day. In the present study the C. roseus leaves reduced the fecundity of P. fuscipes females perhaps through inhibition of feeding. Now Catharanthus roseus may be a new safer, eco-friendly insecticide for the control of P. fuscipes.