PATOGENISITAS NEMATODA Heterorhabditis sp. TERHADAP KUMBANG DAUN KELAPA Brontispa longissima GESTRO - WIRATNO WIRATNO; ROHIMATUN ROHIMATUN (Jurnal Penelitian Tanaman Industri, 2012)
ABSTRAKSuatu bioassay telah dilakukan di Balai Penelitian TanamanRempah dan Obat Bogor, dari bulan November 2010 sampai dengan Maret2011, yang bertujuan untuk mengetahui potensi Heterorhabditis sp. dalammengendalikan Brontispa longissima. Nematoda dipanen dengan carameletakkan larva Tenebrio molitor mati terinfeksi nematoda patogenserangga (NPS) di atas kertas saring yang diletakkan di dalam cawan petriberisi 30 ml air. Juvenil infektif (JI) yang ada di dalam tubuh larva akankeluar dan hidup di dalam air. Suspensi JI kemudian dilarutkan 1.000 kalilalu populasinya dihitung di bawah mikroskop binokuler dan diulang 3kali. Populasi JI diperoleh dengan melarutkan 10 ml suspensi dengansejumlah air sehingga diperoleh populasi 7.000, 3.500, 1.750, 875, 438,dan 0 JI/ml air. Masing-masing perlakuan diujikan pada 10 ekor larva,pupa, dan imago dengan menyemprotkan 2 ml suspensi JI. Pengamatanmortalitas B. longissima dilakukan pada 24, 48, dan 72 jam setelahinfestasi (JSI). Hasil penelitian menunjukkan bahwa patogenisitasHeterorhabditis sp. tertinggi pada stadia larva diikuti imago dan pupa.Pada populasi 3.500 JI/ml air kematian larva, imago, dan pupa pada 24 JSIberturut-turut sekitar 73, 63, dan 10%, berbeda tidak nyata denganperlakuan 7.000 JI/ml air. LC 50  Heterorhabditis sp. terhadap larva, imago,dan pupa pada 72 JSI berturut-turut 1.492, 2.622, dan 800.818 JI/ml air.Kata kunci: Brontispa  longissima,  kelapa,  Heterorhabditis  sp.,patogenisitasABSTRACTIn order to evaluate the potensial of Heterorhabditis sp. incontrolling B. longissima bioassays was conducted in IndonesianResearch Institute for Spices and Medicinal Crops, Bogor from November2010 until March 2011. Infective juveniles (IJ) of the nematodes wereharvested by putting dead Tenebrio molitor on a filter paper placed in apetri dish containing 30 ml of water. IJs in the larval body will then go outand live in the water. The suspension was then diluted 1,000 times andthen population counted under a binocular microscope and repeated 3times. IJ population is obtained by dissolving 10 ml suspension to obtain7,000; 3,500; 1,750; 875; 438; and 0 IJs/ml of water. Each treatment wastested on 10 larvae, pupae, and adults by spraying 2 ml IJ suspension.Mortality observations were made at 24, 48, and 72 hours after infestation(HAI). The results showed that the highest Heterorhabditis sp.pathogenicity was found in larvae stadium followed by pupae and adultstadia. In the 3,500 IJ population/ml of water, larvae, imago, and pupaemortalities in 24 HAI were approximately 73, 63, and 10%, respectivelyand were not significantly different with 7,000 IJ/ml of water. LC 50 valuesof Heterorhabditis sp. on the larvae, adult, and pupae in 72 HAI were1,492; 2,622; and 800,818 IJ/ml of water, respectively.Key words: Brontispa longissima, Cocos nucifera, Heterorhabditis sp.,pathogenicity