<![CDATA[Abstract—Various efforts have been made to improve the quality of crop production, cabbage was one of them. Cabbage is one of the largest export holticultural commodities in Indonesia. Loss often happened because of insect pests. Armyworm (Spodoptera litura) is one of the pests that are often found in cabbage plants. To handle pest attacks, farmers can replace chemical insecticides uses to bioinsecticides. This study tested the pathogenicity of Enterobacter aerogenes B4 isolates against Spodoptera litura by exposing the isolates through feed and injection. In pathogenicity test through feed, isolates with concentrations of 105, 106, and 107 CFU/mL were used. The highest mortality was found in larva with exposure of isolates with a concentration of 107 CFU/mL as many as 9 caterpillars dies for 6 days. LC50 calculation could not be carried out because the mortality of larva with the highest concentration did not reach 50%. Then in the pathogenicity test through injection, no death was found after exposure for 2 days. The results obtained from both pathogenicity tests were Enterobacter aerogenes B4 isolates were not pathogenic to Spodoptera litura. Keywords: armyworm (spodoptera litura), bioinsecticide, patogenicity test. Abstrak—Berbagai macam upaya dilakukan untuk meningkatkan kualitas produksi tanaman, salah satunya kubis. Kubis merupakan salah satu komoditas holtikultura ekspor terbesar di Indonesia. Tak jarang terjadi gagal panen disebabkan oleh serangan hama serangga. Ulat grayak (Spodoptera litura) merupakan salah satu hama yang sering ditemukan pada tanaman kubis. Untuk menangani serangan hama petani dapat beralih dari insektisida kimia menggunakan bioinsektisida. Penelitian ini melakukan uji patogenisitas isolat Enterobacter aerogenes B4 terhadap Spodoptera litura dengan memaparkan isolat melalui pakan dan injeksi. Pada pengujian patogenisitas melalui pakan digunakan isolat dengan konsentrasi 105 , 106 , dan 107 CFU/mL. Didapatkan kematian ulat terbanyak pada ulat dengan paparan isolat konsentrasi 107 CFU/mL sebanyak 9 ekor ulat selama 6 hari. Tidak dapat dilakukan penghitungan LC50 karena kematian ulat dengan konsnetrasi tertinggi tidak mencapai 50%. Lalu pada pengujian patogenisitas melalui injeksi tidak didapatkan kematian ulat setelah paparan selama 2 hari. Hasil yang didapatkan dari kedua pengujian patogenisitas yaitu isolat Enterobacter aerogenes B4 tidak bersifat patogen terhadap Spodoptera litura. Kata kunci: ulat grayak (spodoptera litura), bioinsektisida, uji patogenisitas]]>
