ABSTRAK Cendawan Aspergillus berpotensi sebagai agen biokontrol terhadap rayap. Penelitian ini bertujuan untuk mengetahui patogenisitas beberapa isolat cendawan Aspergillus spp. terhadap rayap Coptotermes curvignathus dan mengetahui simtomatologi rayap yang terinfeksi isolat cendawan Aspergillus spp. Metode penelitian yang digunakan adalah metode eksperimental dengan Rancangan Acak Lengkap (RAL) untuk mengetahui pengaruh tiga isolat Aspergillus spp. terhadap mortalitas rayap. Analisis probit digunakan untuk memperoleh nilai Median Lethal Concentration (LC50) dan Median Lethal Time (LT50). Hasil pengujian patogenisitas menunjukkan bahwa nilai LC50 terendah diperoleh dari isolat Aspergillus sp. 1 sebesar 4,7x103 konidia/mL dengan nilai LT50 pada kerapatan konidia 103 konidia/mL adalah 6,9 hari. Nilai LT50 yang diperoleh semakin menurun pada kerapatan konidia yang semakin meningkat. Besarnya persentase mortalitas rayap C. curvignathus tertinggi akibat isolat Aspergillus spp. mencapai lebih dari 80%. Simtomatologi rayap setelah terinfeksi cendawan Aspergillus spp. menunjukkan proses mumifikasi dan permukaan tubuh rayap ditutupi oleh miselium dengan warna miselium koloni cendawan yang tumbuh sesuai dengan warna koloni cendawan pada media Potato Dextrose Agar (PDA). Kata kunci: Cendawan entomopatogen, Aspergillus spp., patogenisitas, Coptotermes curvignathus ABSTRACT Fungus Aspergillus is a potential biocontrol agent against termites. This research aimed to study the pathogen activity of fungi isolates Aspergillus spp. on termite Coptotermes curvignathus and to know the symptomatology of termites after being infected by fungus Aspergillus spp. Method used in this study was experimental method with completely randomized design in order to investigating effects of three isolates Aspergillus spp. on termite mortality. The probit analysis was used to determine Median Lethal Concentration (LC50) and Median Lethal Time (LT50) values. The result of pathogenicity assay showed that the lowest value LC50 was from isolate Aspergillus sp. 1 with 4,7×103 conidia/mL and LT50 value for conidial density of 103 conidia/mL was 6,9 days. In addition, the LT50 values decreased in respond to the increase of conidial density. Highest mortality rate of termite C. curvignathus at 80% was assumed due to the isolates fungal Aspergillus spp. Symptomatology of termites after being infected by fungus Aspergillus spp. showed the mummification process and the body of termite was covered by mycelium of fungal colony with the color of the fungal colony that growth in accordance with the color of the fungal colony on the Potato Dextrose Agar (PDA) media. Key words: Entomopathogenic fungus, Aspergillus spp., pathogenicity, Coptotermes curvignathus