COMPARATIVE EFFICACY OF THREE INSECT GROWTH REGULATORS ON THE DEVELOPMENTAL STAGES OF CULEX TRITAENIORHYNCHUS

The effect of three Insect Growth Regulators (Diflubenzuron, Methoprene and Bti) was studied on the eggs, fourth stage larvae and pupae of Culex tritaeniorhyncus. The LC 50 of the insecticides was minimum when applied against 4 th stage larvae than on eggs or pupae. Methoprene had the least LC 50 followed by diflubenzuron. High concentrations of Bti were required to produce the desired effect. When maximum retail price was considered, diflubenzuron was the best followed by methoprene. Bti was most expensive.