Efikasi Dan Persistensi Minyak Serai Sebagai Biopestisida Terhadap Helicoverpa Armigera Hubn. (Lepidoptera : Noctuidae)

Abstract

. Hasyim, A., W. Setiawati, R. Murtiningsih, and E. Sofiari. 2010. Efficacy and Persistence of CitronellaOil as A Biopesticide Against Helicoverpa armigera Hubn.. The fruit borer, Helicoverpa armigera (Hubn.) is one ofthe key pests of Chili pepper in Indonesia. Yield loss due to this insect pest is up to 60%. The chemical treatment forcontrolling this insect pest is ineffective and eventually leads to environmental pollution. Studies were conducted toassess the biological activity of citronella oil against tomato fruit worm, H. armigera from June to December 2009 atthe Laboratory and the Screenhouse at Indonesian Vegetables Research Institute. All the bioassays were conducted undercontrolled environmental conditions (27± 20C and 75-80% RH). Four bioassay steps were performed, i.e the effectof citronella oil on percentage repellency of second instar larvae of H. armigera, the antifeedant effect of citronellaoil against third instar larvae of H. armigera, toxicity of citronella oil on first, second, and third instar larvae of H.armigera and persistence of citronella oil and is effect of mortality of H. armigera. The results indicated that citronellaoil significantly repellened to second larvae of H. armigera with the repellency level of relative lowest II (20-40%) andIII (40-60%). Applications of citronella oil at 3,000 until 5,000 ppm concentrations reduced the food consumptionindex, growth rate, approximate digestability, efficiency of conversion of digested food and feeding deterrent was reducedby 50%. Citronella oil significantly decreased the growth and the development of both pupal male and female of H.armigera. The percentage of mortality rate varied significantly among the H. armigera larvae tested and the values ofLC50 for first, second, and third larvae instar of H. armigera were 12,795.45, 8,327.42, and 3,324.89 ppm, respectively.Meanwhile LC95 value at the first, second, and third larvae instar of H. armigera were 10,564.59, 12,535.12, and 4,725.30ppm, respectively. Residual activity of citronella oil were found to be moderately toxic to H. armigera. The residueof citronella on food H. armigera was about 1-4 days after treatment. However, toxicity decreased significantly after5 days. These results clearly showed that citronella oil was not persistent to the environment due to its volatile nature.These results suggested that the application of citronella oil is potential to be used as an ideal eco-friendly approach forthe control of the agricultural pests H. armigera