Patogenisitas Beauveria bassiana (Bals.) Viull. yang Diisolasi dari Beberapa Jenis Inang Terhadap Kepik Hijau, Nezara viridula L. (Hemiptera: Pentatomidae)
Kepik Hijau (Nezara viridula L.) merupakan hama penting bagi beberapa tanaman pangan seperti kedelai, padi dan jagung. Salah satu upaya untuk mengendalikan hama adalah dengan pemanfaatan entomopatogen, seperti virus, bakteri maupun jamur. Salah satu jamur entomopatogen yang berpotensi untuk dieksploitasi adalah Beauveria bassiana yang mempunyai berbagai jenis inang. Belum diketahui patogenesitas B. bassiana yang diisolasi dari beberapa jenis inang terhadap hama kepik hijau (N. viridula), untuk itulah penelitian ini dilakukan dengan tujuan untuk mengetahui patogenesitas B. bassiana yang diisolasi dari inang yang berbeda terhadap hama kepik hijau (N. viridula). Penelitian ini dilakukan di Laboratorium Agens Hayati (LAH) Kalasey, Balai Perlindungan dan Pengujian Mutu Tanaman Pangan dan Hortikultura (BPPMTPH), Dinas Pertanian dan Peternakan Daerah Provinsi Sulawesi Utara. Penelitian dilakukan secara in- vitro dengan menggunakan Rancangan Acak Lengkap (RAL) dengan 6 perlakuan yaitu (Kontrol negatif , N1: suspensi B. bassiana isolat WBC (wereng batang coklat), N2: suspensi B. bassiana isolat Jati Sari sebagai kontrol positif (rekomendasi Kementan), N3: suspensi B. bassiana isolat Paraeucosmetus pallicornis (kepik hitam), N4: suspensi B. bassiana isolat Leptocorisa acuta (walang sangit) dan N5: suspensi B. bassiana isolat Scotinopara coarctata (kepinding tanah). Perlakuan menggunakan konsentrasi atau kerapatan konidia 109/ml air, dengan 5 ulangan. Data dianalisis dengan Uji Anava 95% dan analisis probit untuk menentukan LT50 (Lethal Time 50). Hasil penelitian menunjukkan bahwa jamur B. bassiana isolat Jati Sari memiliki patogenisitas tertinggi dengan membunuh kepik hijau (N. viridula) sampai 100% pada hari ke-5 HSP (hari setelah perlakuan), sedangkan isolat lain semuanya pada hari ke-6 HSP. Nilai LT50 (waktu yang dibutuhkan untuk membunuh 50% serangga uji) terdapat pada isolat P. pallicornis yaitu 2,1 hari. Persentasi mortalitas pada hari ke-3 HSP tertinggi terdapat pada perlakuan isolat P. pallicornis dengan rata-rata mortalitas sebesar 78% diikuti isolat L. acuta dan S. coarctata masing-masing sebesar 68% dan isolat Jati sari sebesar 58%, sedangkan mortalitas terendah terdapat pada perlakuan isolat WBC yaitu sebesar 32%. Tidak ada perbedaan patogenisitas yang signifikan diantara isolat Jati Sari, P. pallicornis, L. acuta maupun S. coarctata kecuali isolat WBC.Kata kunci: Beauveria bassiana; Entomopatogen; Nezara viridula Pathogenicity of Beauveria bassiana (Bals.) Viull. Isolated from Several Host Species Against Green Ladybug, Nezara viridula L. (Hemiptera: Pentatomidae) ABSTRACTGreen Ladybugs (Nezara viridula L.) are important pests for several food crops such as soybeans, rice and corn. One of the efforts to control this pest is the use of entomopathogens, such as viruses, bacteria and fungi. One of the entomopathogenic fungi that has the potential to be exploited is the fungus Beauveria bassiana. The fungi B. bassiana has various of hosts. There are no data on the pathogenicity of B. bassiana isolated from several host species against green ladybugs (Nviridula), for that reason this study was conducted with the aim of knowing the pathogenicity of B. bassiana isolated from different hosts against green ladybugs (N. viridula).. This research was conducted at Laboratory of Biological Control Agents, the Center for the Protection and Quality Testing of Food Crops and Horticulture, the Regional Agriculture and Livestock Service Office of North Sulawesi Province. The research was conducted in-vitro using a completely randomized design (CRD) with 6 treatments, namely (Negative control, N1: suspension B. bassiana, WBC isolate (brown planthopper), N2: B. bassiana suspension, Jati Sari isolate as a positive control (Ministry of Agriculture Recommendation), N3 : B. bassiana suspension isolate Paraeucosmetus pallicornis (black ladybug), N4: suspension B. bassiana isolate Leptocorisa acuta (Rice ear bug) and N5: suspension B. bassiana isolate Scotinopara coarctata (rice black bug) Treatment using conidia concentration or density 109 / ml water, with 5 replications. Data were analyzed with Anava test 95% and probit analysis to determine LT50 (Lethal Time 50). The results showed that the fungus B. bassiana Jati Sari isolate had the highest pathogenicity, because this isolate was able to kill green ladybugs (N viridula) to 100% on the 5th day of DAT (the day after treatment), while the other isolates were all on the 6th DAT. While the value of LT50 (time needed to kill 50% of the insect test) was found in P. pallicornis isolates which were 2,1 days of DAT. Because LT50 in all isolate treatments was between the 2nd and 3rd day of DAT, the Anava test for mortality was carried out on the 3rd day of DAT. The highest percentage of mortality on the 3rd day of DAT was found in the treatment of P. pallicornis isolates with an average mortality of 78% followed by L. acuta and S. coarctata isolates each at 68% and Jati sari isolates at 58%, while the lowest mortality was found in the treatment of WBC isolates, namely 32%. There was no significant difference in pathogenicity between Jati Sari, P. pallicornis, L. acuta and S. coarctata isolates except for WBC isolates.Keywords: Beauveria bassiana; Entomopatogen; Nezara viridula