We surveyed the distribution of the wild mulberry silkmoth, Bombyx mandarina, using pheromone traps. Male moths were captured in all the prefectures of Japan except Okinawa Prefecture. In Tokara Islands, B. mandarina inhabits Nakanoshima and Akusekijima Islands while it is absent in Takarajima Island, which lies to the south of the Watase line. No Bombyx moths were captured in Iki, Amami, and Okinawa Islands. In addition, we collected B. mandarina in Hachijo Island for the first time. 1) Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan; 2) Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyoku, Kyoto, 606-8585, Japan; 3) Genetic Resource Center, National Agriculture and Food Research Organization, 6585 Kobuchisawa, Hokuto, Yamanashi, 408-0044, Japan; 4) Gunma Sericultural Technology Center, 2326-2 Soja, Soja-machi, Maebashi, 371-0852, Japan; 5) Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki 036-8561, Japan; 6) Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, 2321 Suya, Koshi, Kumamoto 861-1192, Japan; 7) Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan.