Nematus japonicus (Takeuchi, 1921)

Japanese name: Hiraashi-habachi

Material examined. HONSHU: Tochigi Pref.: 3 $, Nakagawa, Yamata, coll. larvae on Alnus sieboldiana 30. IX. 2018 , mat. 2. X., em. 10. IX. 2019, S. Ibuki; 3$, same data but mat. 3. X., em. 14. IX. 2019 .

Host plants. Betulaceae: Alnus firma Siebold et Zucc., A. hirsuta Turcz. var. hirsuta, A. japonica (Thunb.) Steud., A. inokumae Murai et Kusaka, A. pendula Matsum. (Okutani, 1967); A. sieboldiana Matsum. (new record).

Remarks. We here record A. sieboldiana as a new host plant. This sawfly is associated with various species of Alnus .