Repellent Activity of Piper spp. Leaves Extracts on Rice Ear Bugs (Leptocorisa oratorius Fabricius) and the Characters of Its Volatile Compounds

Abstract

Rice ear bug (Leptocorisa oratorius Fabricius) is still classified as the top of five pests that cause the most losses in rice farming productivity. The attack causes the grain to become empty resulted in reducing the yield of grain up to 40% even to 100%. Betel plants (Genus Piper) are easy to grow and grown by almost all households in Indonesia. Ethnobotany showed that betel is used as one of the insect controllers. This research aimed to study the repellant activities of five species of Piper spp. and their phytochemical composition based on CG-MS chromatograms. Moreover, the active compounds were analyzed in potent plant. The repellant activities of chloroform and methanol extract of P. betle, P. aduncum, P. nigrum, P. longum, and P. crocatum were applied using modified olfactometer, while the phytochemical composition were analyzed using GC-MS. The compounds with insecticidal activity in the potent species were analyzed by the references. The results showed that chloroform extract of P. crocatum was the most potent extract. It contains 28 specific compounds which were not found in other species. Literature studies showed that compounds that had repellent activities are monoterpene and sesquiterpene groups.