Pristiphora geniculata (Hartig, 1840)

New Japanese name: Nanakamado-higenaga-habachi

(Fig. 12)

Material examined. HOKKAIDO: 25$2 Ə, Engaru, coll. larvae on Sorbus commixta, 22. VII. 1993, coc. 24–26. VII., em. 9–12. VIII. 1993, H. Hara, and progeny of one of those $, 1 Ə, egg laid 10. VIII. 1993, em. 16. IX. 1993, H. Hara; 9 $, Tokachigawa-onsen, coll. gregarious larvae on Sorbus commixta, 8. VII. 2008, mat. 9–11. VII., em. 23–25. VII. 2008, H. Hara (Fig. 12A–B); 13$6Ə , Yakumo, coll. 140 early-instar gregarious larvae on Sorbus commixta, 20. VI. 2008, coc. 29. VI. – 1. VII., em. 11–23. VII. 2008, H. Hara (Fig. 12C–G). — HONSHU : Gunma Pref.: 12$1 Ə, Manzaonsen, 36°38′N 130°30′E, coll. larvae on Sorbus commixta, 16. VIII. 2022, mat. 16–18. VIII., em. 5–6. IX. 2022, H. Kojima .

Distribution. Japan (new record): Hokkaido, Honshu. Palaearctic (see Sundukov, 2017, for details), N. America (introduced; Forbes and Daviault, 1964).

Host plants. Rosaceae: Sorbus commixta Hedl. (new record). This species is associated with various species of Sorbus . For the host plants outside Japan, see Prous et al. (2017). This sawfly is well known as a pest in North America (Forbes and Daviault, 1964; Looney et al., 2016).

Remarks. This Palaearctic species is here recorded from Japan for the first time. The Japanese females and males go to Pristiphora geniculata in the key to North-Western Palaearctic species of Pristiphora by Prous et al. (2017). Their lancets and penis valves are identical with those of European specimens respectively (compare Fig. 12A, E with figs. 150, 229 in Prous et al., 2017). The final instar larva of Japan (Fig. 12G) is also almost the same as the European larva figured by Macek et al. (2020, p. 537, fig. 4).