Efikasi dan Persistensi Minyak Serai sebagai Biopestisida terhadap Helicoverpa armigera Hubn. (Lepidoptera : Noctuidae) - Ahsol Hasyim; Wiwin Setiawati; R Murtiningsih; Eri Sofiari (Indonesian Center for Horticulture Research and Development, 2010)
ABSTRAK. Helicoverpa armigera merupakan hama penting pada tanaman cabai merah. Kehilangan hasil akibat seranganH. armigera dapat mencapai 60%. Pengendalian yang umum dilakukan adalah menggunakan insektisida secara intensif,yang dapat menimbulkan berbagai dampak negatif. Penelitian bertujuan mengetahui pengaruh berbagai konsentrasiminyak serai terhadap aktivitas biologi larva H. armigera. Penelitian dilaksanakan di Laboratorium dan Rumah KasaBalai Penelitian Tanaman Sayuran, Lembang dari bulan Juni sampai Desember 2009 pada suhu 27±20C dan kelembaban75-80%. Penelitian dilaksanakan dalam empat tahap kegiatan, yaitu pengaruh minyak serai terhadap: (1) repelensi larvaH. armigera instar II, (2) indeks nutrisi larva H. armigera instar III, (3) toksisitas larva H. armigera instar I, II, dan III,serta (4) persistensi minyak serai dalam pakan H. armigera dan pengaruhnya terhadap mortalitas larva H. armigerainstar III. Rancangan percobaan yang digunakan ialah acak kelompok yang terdiri atas enam perlakuan dengan empatulangan. Penelitian menggunakan metode pencelupan (dipping methods). Hasil penelitian menunjukkan bahwa minyakserai dapat digunakan sebagai penolak larva H. armigera instar II, dengan tingkat repelensi kelas II (20-40%) dan kelasIII (40-60%). Aplikasi minyak serai pada konsentrasi 3.000-5.000 ppm dalam pakan dapat menurunkan laju konsumsirelatif, laju pertumbuhan relatif, efisiensi konversi makanan yang dicerna dan yang dimakan, serta dapat menghambatmakan larva H. armigera sebesar 50%. Penggunaan minyak serai dapat menurunkan bobot pupa H. armigera jantandan betina. Nilai LC50 untuk larva H. armigera instar I, II, dan III berturut-turut ialah 12.795,45, 8.327,42, dan 3.324,89ppm, sedang nilai LC95 untuk larva H. armigera instar I, II, dan III berturut-turut sebesar 10.564,59, 12.535,12, dan4.725,30 ppm. Residu minyak serai dalam pakan H. armigera hanya berkisar antara 1- 4 hari setelah pemaparan ataupada 5 HSP toksisitas menurun drastis. Minyak serai sebagai insektisida nabati mempunyai tingkat persistensi yangrelatif rendah. Hasil penelitian menunjukkan bahwa, minyak serai dapat digunakan sebagai insektisida yang potensialuntuk dikembangkan secara komersial dan ramah lingkungan dalam rangka pengendalian H. armigera.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.