<p>ABSTRAK<br />Nematoda entomopatogen Steinernema sp. telah banyak<br />dimanfaatkan sebagai agens hayati untuk mengendalikan serangga hama di<br />luar negeri, namun di Indonesia masih terbatas. Tujuan penelitian adalah<br />mengevaluasi efektivitas 3 strain Steinernema sp. lokal terhadap beberapa<br />hama utama tanaman perkebunan dan hortikultura. Penelitian ini dilakukan<br />di Laboratorium Entomologi dan Kebun Percobaan, Balai Penelitian<br />Tanaman Tembakau dan Serat Malang, Jawa Timur, mulai April 2001<br />sampai Mei 2002. Tiga strain nematoda lokal, yaitu BT02, ML07, dan<br />AB05 diuji masing-masing pada konsentrasi 50; 100; 200; 400; dan 800<br />Juvenil infektif (JI)/ml dan satu kontrol (tanpa JI). Sembilan spesies<br />serangga hama yang diuji yaitu Helicoverpa armigera, dan Pectinophora<br />gossypiella (hama kapas), H. assulta dan Myzus persicae (tembakau),<br />Plutella xylostella, dan Crocidolomia binotalis (kubis), Spodoptera exigua<br />(bawang merah), Liriomyza sp. dan S. litura (bunga krisan). Setiap spesies<br />serangga mewakili satu unit pengujian. Setiap perlakuan dalam unit<br />disusun dalam rancangan acak lengkap (RAL) dengan empat ulangan.<br />Aplikasi perlakuan dilakukan dengan metode vial, kultur sel, dan sumuran,<br />tergantung perilaku serangga uji dan menggunakan spray chamber. Di<br />laboratorium, parameter yang diamati adalah sublethal (LC 25 ) dan lethal<br />concentration (LC 50 ), sublethal and lethal time (LT), dan produksi JI. Di<br />lapang, hanya satu perlakuan tunggal yang digunakan yaitu LC 50 dari<br />setiap strain nematoda. Sebanyak masing-masing 20 inang serangga<br />dipajankan daun atau bagian tanaman yang telah disemprot dengan<br />suspensi nematoda di lapang, kemudian serangga uji diamati di<br />laboratorium hingga mati. Hasil penelitian menunjukkan bahwa ketiga<br />strain nematoda menunjukkan efektif membunuh C. binotalis (BT02), P.<br />xylostella, M. persicae (ML07), dan P. gossypiella (AB05), tetapi kurang<br />efektif terhadap H. armigera (AB05), S. exigua dan S. litura (ML07), dan<br />Liriomyza sp. (BT02). Waktu efektif yang diperlukan nematoda untuk<br />membunuh inang (Lethal Time) pada ketiga strain berkisar antara 1-4 hari.<br />Selain efektif membunuh stadia larva, Steinernema sp. juga efektif<br />terhadap prepupa dan pupa.<br />Kata kunci : Tanaman perkebunan, hortikultura, Steinernema sp.,<br />Helicoverpa armigera, Pectinophora gossypiella, H.<br />assulta, Myzus persicae, Plutella xylostella, Crocidolomia<br />binotalis, Spodoptera exigua, S. litura, Liriomyza sp., juvenil<br />infektif, mortalitas</p><p><br />ABSTRACT<br />Effectiveness of entomopathogenic nematode Steiner-<br />nema sp. against major insect pests of plantation and<br />horticulture<br />Entomopathogenic nematode of family Steinernematidae is a<br />prospective agent for biological control of insect pests. It has been known<br />that many species of insects can be infected by nematode and sometimes<br />showed different levels of infection. Laboratory and field study on the<br />effectiveness of Steinernema sp. against major insect pests of plantation<br />and horticulture was carried out in Laboratory of Entomology and<br />Experimental Station of Indonesian Tobacco and Fiber Crops Research<br />Institute (IToFCRI), Malang, East Java. The objective was to find out the<br />effectiveness of three local strains of Steinernema sp. to any different<br />major of insect pests of plantation and horticulture. Three local strains of<br />nematode tested as BT02, ML07, and AB05 which each consist of five<br />level concentrations of IJ, viz. 50, 100, 200, 400 and 800 IJ/ml and one<br />untreated with IJ as control were tested against nine species of insect, viz.<br />H. armigera, P. gossypiella (cotton), H. assulta and M. persicae (tobacco),<br />P. xylostella and C. binotalis (cabbage), S. exigua (red onion), Liriomyza<br />sp. and S. litura (chrysanthemum). Each species of insect was tested as<br />one unit of test and treated with the same level of concentration. Each<br />treatment in every unit of test was arranged in randomized complete<br />design with four replications. Application method of treatment used were<br />vial, cell culture plate, and well, depends on insect behaviour. Nematode<br />suspension was applied by using spray chamber. Parameters observed<br />were sublethal and lethal concentration, sublethal and lethal time and IJ<br />production. In field study, only one single treatment LC 50 was used to<br />observe the insect mortality. In this study, twenty of insect hosts were fed<br />on treated-sample leaves collected from the field and observed till death.<br />The result showed that all strains of Steinernema sp. were more<br />pathogenic and effective against C. binotallis (BT02), P. xylostella and M.<br />persicae (ML07), and P. gossypiella (AB05), but less pathogenic against<br />H. armigera (AB05), S. exigua and S. litura (ML07), and Liriomyza sp.<br />(BT02). Time needed (LT) to kill the insect host was ranged from one to<br />four days. Strains of nematode tested were not only effective against larvae<br />but also effective to kill prepupae and pupae of insect host.<br />Key words : Estate crops, horticulture, Steinernema sp., H. armigera, P.<br />gossypiella, H. assulta, M. persicae, P. xylostella, C.<br />binotalis, S. exigua, Liriomyza sp, S. litura, infective<br />juvenile, mortality</p>
Population of Spodoptera exigua Hübner during On- and Off-Season of Shallot in Bantul Regency, Yogyakarta