Armitarsus watanabei Shinohara, 2002

Bourke, Joanna, 2024, Taxonomic Notes and New Distribution and Host Plant Records for Sawflies and Woodwasps (Hymenoptera, Symphyta) of Japan IX, Bulletin of the National Museum of Nature and Science. Series A, Zoology 50 (1), pp. 19-32 : 25-26

Armitarsus watanabei Shinohara, 2002

Japanese name: O-koshijiro-togeashi-habachi

( Fig. 4)

Material examined. HOKKAIDO: 1˂, Chi- tose, Horoka , 42°54'N 141°47'E, coll. larva on Cerasus sargentii var. sargentii 24. VIII. 2022, mat. 25. VIII., em. 23. IV. 2023, H. Hara .

Larva. Late instar ( Fig. 4A, B): Head black,

laterally dark brown; trunk opaque, blackish, broad lateral margins and apical segment pale brown; paired transverse lines of four or six small tubercles on each segment and numerous small subtriangular projections along lateral mar- gin white; prothoracic segment dorsally with paired white projections along anterior margin; four long subtriangular projections along apical margin of last abdominal segment. Mature larva ( Fig. 4C): Pale reddish brown, surface smooth, without small tubercles or projections.

Distribution. Japan (Hokkaido, Honshu). New record from Hokkaido.

Host plant. Rosaceae : Cerasus sargentii (Rehder) H.Ohba var. sargentii (new record).

Remarks. This species was described from Tokyo, central Honshu ( Shinohara, 2002b) and later recorded from Hyogo Prefecture, western Honshu ( Okutani, 1954, as A. albicinctus ; Naito et al., 2004, as A. albicinctus ; Yoshida, 2014b) and Tochigi Prefecture, central Honshu (Kata- yama, 2011). This is the first distribution record from Hokkaido. The type series of this species was collected on cherry trees ( Shinohara, 2002b) but the immature stages and host plant were unknown. The larva ( Fig. 4) has not been clearly differentiated from the larva of A. albicinctus ( Anonymous, 2014) .