Studies on Feeding Habits of the Brown Planthopper

I. Effects of Nitrogen-deficiency of Host Plant on Insect Feeding

Abstract

Feeding preference, honeydew excretion and probing behaviors of the female adults of the brown planthopper, Nilaparvata lugens (STÅL), on N-deficient and normal rice plants were comparatively studied. The results showed that the N-deficient plants were less preferred for feeding than the normal ones; and also less honeydew excretion by the insects on the N-deficient plants suggested that the insects did less feeding on those plants. Concerning this it is considered that the chemical nature of the N-deficient plants' sap, such as lower concentration of amino nitrogen, appear to adversely affect the insect's feeding, because there was no evidence indicating that the insect's mechanism in locating their feeding sites, the vascular bundles, was disrupted in the N-deficient plants. It was also assumed that poor fecundity of the planthoppers on N-deficient host plants could be due rather to a failure of the insects to take up enough amounts of plant sap than poor nutritive value of the ingested plant sap.