The use of pymetrozine for the control of homopterous insect pests in paddy rice

Pymetrozine gave excellent control of planthoppers in paddy rice under field conditions. However, neither topical nor root systemic treatments led to high mortality under laboratory conditions. Contact treatment with pymetrozine caused paralysis of the legs of treated Nilaparvata lugens and stopped their sucking behaviour. More than half of the treated individuals died from direct poisoning. The survivors did not contribute to reproduction, primarily because of reduced fecundity caused by delayed ovary maturation. This effect was more obvious in immature than mature females. Pymetrozine suppressed the hopper populations of Sogatella furcifera efficiently in the field by both nursery box (systemic) and foliar applications. The duration of its population-suppressive activity against S. furcifera in the field was longer than 2 months by nursery box application at the dose of 300 g a.i./ha and 4 weeks by foliar spray at the dose of 63 g a.i./ha. Pymetrozine also inhibited walking behaviour of the stink bug, Eysarcoris lewisi.