The sublethal doses effect on controlling of the nettle caterpillar Setothosea asigna (Lepidoptera: Limacodidae) on oil palm plantation

Abstract

Abstract The nettle caterpillar, Setothosea asigna, is a major pest in an oil palm plantation in North Sumatra, which causes severe defoliation and reduces productivity. Controlling this pest commonly uses Pyrethroids insecticides, but dimehypo was also used when controlling bagworms and nettle caterpillars in the exact location. The sublethal doses were reported to decrease pest mortality. The study aimed to determine the effect of dimehypo sublethal doses on mortality and pupae acceleration of Setothosea asigna. This study used five doses of treatments using the fogging technique, i.e., 50, 100, 150, 200, and 250 ml/ha, and untreated were tested following a completely randomized design (CRD) with five replications. The results showed that the sublethal doses (50, 100, 150, and 200 ml/ha) had low mortality reached 58.33-62.50%, and the efficacy value reached 52.38-57.14% in seven days after application. The lethal dose (250 ml/ha) has 100% mortality seven days after application, and the efficacy value reaches 80.95% in five days. The sublethal doses of 50, 100, and 150 ml/ha showed an acceleration in the Setothosea asigna pupation on three days and doses of 200 ml/ha on five days from the untreated treatment. This founding could be the reason for Setothosea asigna’s overlapping populations and prolonged the pest outbreak.