SINERGISME ANTARA NEMATODA PATOGEN SERANGGA Steinernema sp. DAN MINYAK BIJI JARAK PAGAR (Jatropha curcas L.) TERHADAP MORTALITAS DAN EFEK LANJUTAN LARVA Spodoptera litura F.

Abstract

The use of chemical insecticides to control pests causes various negative impacts. Thus, environmentally friendly methods of control are much in need recently. The combination of entomopathogenic nematodes and botanical insecticides based on physic nut oil (PNO) has opened up new possibilities of promising control methods against Spodoptera litura F. The objective of the study was to evaluate the combination effect between botanical insecticides PNO and the entomopathogenic nematode Steinernema sp. on S. litura. The research was conducted at the laboratory of Entomology Indonesian Sweetener and Fiber Crops Research Institute from March to June 2012. The treatments were arranged in a completely randomized block design (CRBD) with factorial pattern, replicated four times. The concentrations of PNO were 2,5; 5; 10, and 20 ml/l, control water and control water + 1 g detergent. Concentration of Steinernema sp. were 0,200, 400, and 800 IJ (infective juvenile)/ml. Nematodes were added simultaneously after application of PNO. Insect larvae were exposed to various concentrations of Steinernema sp. and PNO. Numbers of dead larvae were observed at 24, 48, 72, 96, 120 hours after spraying. The result showed that the concentration combination between PNO and nematode which resulted maximum larvae mortality is 10 ml/l and 400 IJ/ml or 2,5 ml/l and 800 IJ/ml. The impacts of PNO were disabled prepupa and pupa, decrease of eggs number and hatching ability. The increase of concentration used from 2.5 to 20 ml/l resulted the decreased of hatching from 76.29 to 36.37%.