Abstract
Detailed observation of ovipositional lesions made on leaf sheaths of rice plants by rice planthoppers revealed that the mean lesion length on the epidermis was significantly longer and the mean number of injured parenchymal tissue walls was significantly larger in Sogatella furcifella than in Nilaparvata lugens. Formation of watery lesions that have a close bearing on the ovicidal response of rice plants was induced by Sogatella-type and Nilaparvata-type artificial injury made on leaf sheaths at the rate of 55.2 and 65.5%, respectively. This result gives the first evidence for the induction of an ovicidal response in the absence of chemical substances derived from planthoppers.
