Arge gracilicornis (Klug, 1814)

Ryoo, Seung-Woo, Min, Jin-Young, Son, Seok-Yoon, Choi, Baek-Yong, Choi, Juho & Min, Kyoung-Bok, 2022, Taxonomic Notes and New Distribution and Host Plant Records for Sawflies and Woodwasps (Hymenoptera, Symphyta) of Japan VII, Bulletin of the National Museum of Nature and Science. Series A, Zoology 48 (4), pp. 193-213 : 194

Arge gracilicornis (Klug, 1814)

Japanese name: Kogata-ruri-chûrenji

( Fig. 1 )

Material examined. Hokkaido: 1 $, Haboro, coll. larva on Rubus idaeus melanolasius , 19. IX. 2007, em. 9. IV. 2008, H. Hara; 1 $, Higashikawa, Asahidake-onsen, coll. seven young larvae (HH070812C) on Rubus idaeus , 12. VIII. 2007, coc. 22–24. VIII., em. 26. IX. 2007, H. Hara ( Fig. 1A, B ). Honshu: Nagano Pref.: 1 Ə, Hakuba, Happô, coll. three larvae ( AS 070815A) on Rubus crataegifolius , 15. VIII. 2007, mat. 16–18. VIII., em. 22. X. 2007, A. Shinohara ( Fig. 1D ).

Host plant. Rosaceae : Rubus idaeus L. subsp. melanolasius Focke and Rubus crataegifolius Bunge in Japan (new record). In Europe, several species of Rubus including the nominotypical sub- species of Rubus idaeus and Rosa canina L. are known as the host plants ( Taeger et al., 1998).

Life history. This sawfly is probably multivoltine in Japan. Young larvae are gregarious. The hibernation is done in a cocoon.

Remarks. The host plant of this sawfly is recorded for the first time in Japan (see also Okutani, 1967a). The Japanese larva ( Fig. 1 ) is similar to the European larva described by Lorenz and Kraus (1957) and figured by Lacourt (2020) and Macek et al. (2020). The head color pattern seems to vary in European specimens (compare figs. 2, 3, pl. 5 in Lacourt, 2020, with fig. 4, p. 79 in Macek et al., 2020), while the known late instar larva from Japan has mostly black head ( Fig. 1 ).

Figures

Fig. 1. Arge gracilicornis: A, B, Late instar larvae, Asahidake-onsen, 18. VIII. 2007; C, late instar larva, Shigakogen, 3. IX. 2006; D, final instar larva, Hakuba, 17. VIII. 2007. A, B, Photographed by Hara; C, D, photo- graphed by Shinohara.