Studies on the Biological Parameters of Brown Planthopper (Nilaparvata lugens Stal) on Oil-Treated Rice Plants

Abstract

The brown planthopper (Nilaparvata lugens Stal) is a major sap-feeding pest of rice, responsible for severe yield losses and hopper burn symptoms. The present investigation was carried out to study the influence of selected plant oils on the biological parameters of N. lugens when exposed through treated rice plants. Four oils neem, jatropha, eucalyptus, and lemongrasswere selected based on preliminary screening and evaluated on the susceptible rice variety TN1 under controlled conditions. The biological parameters studied included pre-oviposition period, incubation period, fecundity, nymphal instars and their duration, total nymphal period, nymphal survival, and adult longevity. Significant variations were observed among oil treatments and the untreated control. Neem oil exhibited the strongest antibiosis effect by significantly prolonging developmental periods, reducing fecundity and nymphal survival, and shortening adult longevity. The findings indicate that botanical oils, particularly neem oil, adversely affect the growth and reproduction of N. lugens and may be effectively utilized as eco-friendly components in integrated pest management strategies for rice.