AbstrakBeauveria spp. merupakan salah satu jamur entomopatogen yang dapat digunakan sebagai agen biokontrol terhadap berbagai serangga hama. Tujuan penelitian ini adalah untuk menguji patogenitas Beauveria spp. terhadap serangga wereng coklat (Nilaparvata lugens Stål). Isolat-isolat Beauveria spp. diisolasi dari serangga walang sangit dari Situ Gede, Bogor, Jawa Barat. Identifikasi jamur dilakukan berdasarkan analisis data sekuen dari daerah Internal Transcribed Spacer (ITS) rDNA. Hasil uji menunjukkan bahwa patogenisitas isolat Stgd 5(14)2 dan Stgd 7(14)2 menghasilkan tingkat mortalitas 100% terhadap N. lugens. Isolat Stgd 5(14)2 dan Stgd 7(14)2 memiliki nilai LT50 yang rendah, danmenyebabkan kematian yang cepat terhadap wereng coklat. Hasil analisis filogenetik menunjukkan bahwa sekuen Stgd 5(14)2 dan Stgd 7(14)2 termasuk ke dalam spesies Beauveria bassiana s.str. Hasil studi ini merupakan kajian awal terhadap patogenisitas jamur entomopatogen B. bassiana terhadap wereng coklat, dan distribusinya di pertanaman padi Situ Gede, Jawa Barat.Abstract Beauveria spp. is one of the entomopathogenic fungi that can be used as biocontrol agents against various insect pests, including brown planthopper (Nilaparvata lugens Stal). This study aimed to test the pathogenicity of Beauveria spp. against N. lugens. Beauveria spp. were isolated from the rice stink bug insects, collected from Situ Gede, Bogor, West Java. Fungal identification was carried out based on the internal transcribed spacer (ITS) rDNA analysis. The pathogenicity assay revealed that Stgd 5(14)1 and Stgd 7(14)2 isolates were virulent against N. lugens, with a mortality of 100%. The LT50 (median lethal time) determination, indicated that Stgd 5(14)2 and Stgd 7(14)2 isolates had low value indicating a faster mortality in brown planthopper insects. Phylogenetic analysis showed that the sequences of Stgd 5(14)2 and Stgd 7(14)2 belong to Beauveria bassiana s.str. This is the preliminary pathogenicity trial of entomopathogenic fungi B. bassiana against brown planthopper and their distribution in rice-growing, Situ Gede area in West Java.