Taxonomic Notes and New Distribution and Host Plant Records for Sawflies and Woodwasps (Hymenoptera, Symphyta) of Japan VI Author Fu, Yuanzun Author Yuan, Yuan Author Shen, Qian Author Xu, Hao Author Ye, Zheng Author Guo, Li Author Wu, Xiaoliang Author Zhao, Yunhe text Bulletin of the National Museum of Nature and Science. Series A, Zoology 2021 2021-11-22 47 4 163 188 http://dx.doi.org/10.1039/d4cp01914h journal article 10.50826/bnmnszool.47.4_163 2434-091X 12760197 Siobla japonica Shinohara, Wei and Niu, 2013 Japanese name: Nihon-koshiaka-habachi ( Fig. 9H–I ) Material examined . HONSHU: Tochigi Pref. : 1˂, Nakagawa, Wami, 33°45′N 140°09′E , coll. larva, on Impatiens textorii or Circaea mollis , 5. VI. 2019 , mat. 8. VI., em. 8. IV. 2020 , S. Ibuki; 1ˁ, Nakagawa, Wami, 33°45′N 140°09′E , coll. larva, on Impatiens textorii or Circaea mollis , 5. VI. 2019 , mat. 9. VI. ( Fig. 9I ), em. 11. IV. 2020 , S. Ibuki. Larva . Late instar ( Fig. 9H ): head purplish black; trunk and legs creamy white, dorsal region dark gray, sparsely covered with irregular black spots, each segment with paired yellowish dorsolateral thorns, and black line along ventral margin of pleural region. Mature larva ( Fig. 9I ): blackish, shiny; thoracic legs creamy white. Host plants. Balsaminaceae : Impatiens textorii Miq. (new record). Onagraceae : Circaea mollis Siebold et Zucc. (new record). Life history . This is a univoltine species. The larva is a solitary external feeder and, when matured, it has an extra molt before entering the soil. Remarks. This species is fairly common in central Honshu ( Shinohara et al. , 2013 ), but its immature stages and host plants were totally unknown. Like the preceding species, S. ferox , S. japonica seems to be a polyphagous species with long larval feeding period. The larva of this species may be distinguished from that of S. ferox by the dark color pattern of the head and dorsal region of the trunk in the feeding stages (compare A–C, E–F with H in Fig. 9 ) and the creamy white thoracic legs of the mature larva (compare D, G with I in Fig. 9 ).