Antifeedant effects of precocene II in the brachypterous females of the rice brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae)

Newly moulted females of Nilaparvata lugens Stal were exposed to precocene II residue at a concentration of 3μg/cm2 by contact method for 1 hour. Honeydew excretion of these females along with control insects was measured by the determination of area of spot and volume of honeydew excreted. The P II treatment induced significant reduction in honeydew excretion level. It never reached the control level throughout the period of 10 days observation. As the rate of excretion of honey dew is positively correlated with the intake of sap, the observed decrease in honeydew excretion is due to the lower intake of plant sap by the P II treated insects. Thus, P II induced long term irreversible antifeedant effects in the females of N. lugens.