Potensi Insektisida Melur (Brucea javanica L. Merr) dalam Mengendalikan Hama Kubis Crocidolomia pavonana (F.) (Lepidoptera: Crambidae) dan Plutella xylostella (L.) (Lepidoptera: Yponomeutidae)

Abstract

This study was conducted to evaluate the potency of Brucea javanica (melur) for controlling two species ofcrucifer pests, i.e. Crocidolomia pavonana and Plutella xylostella. Melur fruits, twigs, and leaves were extracteddirectly with methanol or sequentially with hexane, ethyl acetate, and methanol. The most active extract was thenfractionated by preparative layer chromatography using hexane, mixtures of ethyl acetate and methanol, andmethanol as eluents. The most active fraction was formulated as EC (emulsifiable concentrate) and WP (wettablepowder) formulations, and tested for their toxicity and antifeedant effect against C. pavonana and P. xylostellalarvae. The results showed that methanol extract of melur fruits was more active than that of twigs and leaves.Fractionation of methanol extract of melur fruits yielded an active fraction which was eluted with ethyl acetate-methanol 9:1. EC and WP formulations of melur fruits were active against C. pavonana larvae with LC50 of 0.39%and 0.21%, respectively. The same formulations were also active against P. xylostella larvae with LC50 of 0.31% and0.54%, respectively. In no-choice tests, the antifeedant effect of the EC formulation on C. pavonana larvae (feedinginhibition [FI]: 70.9%-97.5%) was higher than on P. xylostella larvae (FI: 52.2%-83.9%), but the antifeedant effect ofthe WP formulation on the two species was relatively the same. In a choice test, the EC formulation at LC 85completely inhibited feeding by C. pavonana larvae (FI: 100%).