Pamphilius komonensis Takeuchi, 1930

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 : 24

Pamphilius komonensis Takeuchi, 1930

Japanese name: Kaede-hirata-habachi ( Fig. 3; Table 1)

Material examined. HONSHU: Tochigi Pref.: 7 ˂1 ˁ listed in Table 1. Ibaraki Pref.: 3˂ listed in Table 1. SHIKOKU: Tokushima Pref.: Ochiai-toge, Miyoshi, 8. VI. 2021, A. Watanabe. For more records, see Shinohara and Zhou (2006) and Anonymous (2023).

Larva. Early instar ( Fig. 3C): Head black; trunk creamy white. Late instar ( Fig. 3D, G): Head and antenna pale olive. Trunk greenish white; dorsal prothoracic field dark olive; lateral prothoracic shield and cervical sclerite black; thoracic legs and subanal appendage creamy white; lateral basin of suranal plate, suranal hook and subanal plate blackish. Mature larva ( Fig. 3H): Head pale olive or pale brownish green with antennae dark brown. Trunk including all appendages vivid pale green; dorsal prothoracic field concolorous to head or blackish; lateral pro- thoracic shield and cervical sclerite black; lateral basin of suranal plate, suranal hook and subanal plate dark olive to black; central basin of suranal plate often blackish.

Distribution. Japan (Honshu, Shikoku, Kyushu). New record from Ibaraki Prefecture and Tokushima Prefecture.

Host plant. Sapindaceae : Acer pictum Thunb. ( Shinohara and Okutani, 1983), A. amoenum Carrière var. amoenum (new record), A. palmatum Thunb. (new record), A. pictum Thunb. subsp. dissectum (Wesm.) H.Ohashi f. connivens (G.Nicholson) H.Ohashi (new record).

Life history. The collection records of over 1000 specimens ( Shinohara and Zhou, 2006; Anonymous, 2023) show that the adults are active in the field mainly in May, the earliest record being April 21, 2007, in the lowland of Hiratsuka City, Kanagawa Prefecture and the lat- est record being July 10–13, 1995, in Hachiman- tai (ca. 1000–1300 m alt.), Iwate Prefecture. In Nakagawa, Tochigi Prefecture, the larvae of this species were found in late May to early July, they matured in mid-June to late July, and the adults emerged in mid-April to early May of the follow- ing year ( Table 1). This species is regarded as univoltine as other pamphiliine sawflies.

The larva is a solitary leaf-roller ( Fig. 3). The leaf-roll is made always on the underside of the leaf. It is a specialized, tight, screw-like tube, with the apex closed ( Fig. 3E, F; type b of Vii- tasaari, 2002b). The late instar larva occasionally moves onto another leaf carrying the screw-like abode.

Remarks. Shinohara and Okutani (1983) first recorded the host plant of this species, but the immature stages and biology have not been stud- ied before. As shown above, P. komonensis may be associated with various species of maples. This pamphiliid is widely distributed in Honshu, Shikoku and Kyushu ( Shinohara and Zhou, 2006; Anonymous, 2023). Here we record this species from Ibaraki Prefecture and Tokushima Prefecture for the first time.