Effect of Neem based Insecticide on Nilaparvata lugens, brown planthopper

Abstract

Nilaparvata lugens is the major threat to rice crops throughout Asia. It has become a serious problem because of the feeding behaviour on the stem of rice plants which decreases rice crops yield in the agricultural industries. Neem was found to be good natural insecticide to control the outbreaks of N. lugens due to the presence of bioactive compound namely Azadirachtin (AZA). Neem leaves was extracted and sprayed on rice plants in order to study the mortality of N. lugens, repelllency of rice plants against N. lugens as well as the effect on the body of N. lugens. The result showed that AZA induced the mortality of N. lugens. Three factors were used which are extract concentration, exposure time and temperature. The optimum condition for the mortality rate obtained was 19.56% concentration of neem extract with 35.37 hours of exposure time. This shows that the mortality rate depends on neem extract concentration and exposure time. In contact study, 97% of N. lugens were found dead after 24 hours. AZA also showed good repellency effect over commercial pesticide. Microscopic observation showed that the body of N. lugens deforms when it consume rice plants with neem extract. The content of AZA was qualified by using High Performance Liquid Chromatography which showed that AZA was available in neem leaves that has been extracted. This shows that AZA in neem leaves can be effective insecticide to prevent the outbreaks of N. lugens.