Phymatocera nipponica Togashi, 1958

(Figs 1D, 2B, E, H, I, K, 4D, G, 6I, 7C, E, 8A, D, 9B, H, K, 11A, C, F, 12B, E, F, 14, 15)

Phymatocerus aterrimus [sic]: Matsumura, 1912: 66. Not Klug, 1816.

Tenthredo sp., [Amadokoro-habachi (in Japanese)]: Sasaki 1923: 275.

Phymatocera aterrima: Yano 1932: 488; Takeuchi 1949: 49; Takeuchi 1950: 1341 (part); Takeuchi 1952: 44; Okutani 1954: 80; Togashi 1955: 34; Okutani 1959: 570. Not Klug, 1816.

Phymatocera nipponica Togashi 1958: 161; Togashi 1965: 251; Okutani 1967: 95; Togashi 1972: 62; Togashi 1974: 20; Abe & Togashi 1989: 554; Togashi 1997: 4; Lee et al. 2000: 52; Shinohara 2001: 283; Shinohara 2005: 233; Naito et al. 2004: 31; Yoshida 2006: 60; Haris 2006: 189; Shinohara 2014: 466; Sundukov 2017a: 12; Sundukov 2017b: 52; Lee et al. 2019: 35; Naito 2019: 62; Naito 2020: 361; Hara et al. 2021: 181.

For more literature, see Lee et al. (2000) and Lee et al. (2019).

Additional description: Female and male. Length 8.0–11.0 mm in female (Fig. 14A, B), 6.0–10.0 mm in male (Fig. 14C). OOL:POL 1.6–1.9:1.0 in female, 1.4–1.8:1.0 in male. Postocellar area with lateral furrow elongated. Interocellar furrow indistinct (Fig. 12B) or sometimes distinct. Distance between eyes at anterior tentorial pit 1.1–1.2 × eye height in female, 1.2–1.3 × in male. Frontal area usually distinctly or slightly concave before median ocellus, with lateral margin usually not or barely ridged (Fig. 12B), rarely slightly ridged. Antenna gradually tapering, with length 2.5–2.7 × head width in female, 3.2–3.4 × in male (Fig. 14A, C). In female antenna, flagellum not compressed, with setae slanted toward apex of antenna and as long as or somewhat shorter than middle width of flagellomere 1 in dorsal view (Fig. 9H); basal and middle flagellomeres barely bulging at apices (Fig. 14A); flagellomere 1 with dorsal length 0.67–0.77 × eye height, 3.6–4.4 × apical breadth in lateral view; flagellomere 2 dorsal length 1.1–1.2 × flagellomere 1 dorsal length; flagellomere 7 with length 5.0–6.0 × breadth in lateral view. In male antenna, flagellum compressed from both sides; setae on flagellum, except for relatively short dorsal setae, very long and about as long as 1.5 × middle width of flagellomere 1 in dorsal view (Fig. 9K); dorsal setae slanted toward apex of antenna, and setae on other sides almost erect; basal and middle flagellomeres somewhat bulging at apices (Figs 9K, 14C); flagellomere 1 with dorsal length 0.75–0.87 × eye height, 3.2–4.3 × apical breadth in lateral view; flagellomere 2 dorsal length 1.3–1.4 × flagellomere 1 dorsal length; flagellomere 7 with length 6.7–8.2 × breadth in lateral view.

Mesoscutum, mesoscutellum and metascutellum densely covered with setae. Epicnemium entirely glabrous, rarely with several setae in middle part (only in one male, with setae in large middle part); epicnemial groove distinct, except for short posterior part. Mesepisternum broadly glabrous ventrolaterally. Anepimeron entirely sclerotized. Furrow dividing katepimeron into anterior and posterior parts distinct or indistinct; setae present on posterior raised margin, rarely also near posterior raised margin. Hind tarsus with length of plantar lobe of tarsomere 1 about 0.4–0.6 × distance between plantar lobes of tarsomeres 1 and 2 in female, about 0.3–0.5 × in male. Tarsal claws with inner tooth large but shorter than apical tooth; distance between apices of apical and inner teeth shorter than depth of concavity between these teeth (Fig. 14D). In fore wing, proximal part of vein 2A+3A bifurcated with anterior branch separated from vein 1A and basally narrowing or inconspicuous (Fig. 4D), rarely distinct throughout and fused with vein 1A (Fig. 2H), or rarely proximal part of vein 2A+3A simply straight (Fig. 2I); cell 2Rs longer than or as long as cells 1R1 and 1Rs combined in posterior length (Fig. 14A, C); junction of vein Rs and crossvein 2r-rs far proximally from junction of vein Rs and crossvein 3r-m.

Female abdomen dorsally opaque, distinctly microsculptured, but with basal terga widely smooth or slightly microsculptured and shinier than middle and posterior terga (Figs 12E, 14A); male abdomen dorsally mostly smooth and shiny and partly slightly microsculptured (Figs 12F, 14C), rarely widely opaque and distinctly microsculptured. In female, ovipositor sheath 0.82–1.0 × as long as hind tibia; valvula 3 extending slightly before or just to apex of tergum 10 posteriorly, in lateral view with apex narrowly rounded, dorsal edge straight, and ventral edge rounded (Fig. 14E), but sometimes very slightly concave near apex. Ovipositor broad (Fig. 14F). Lance with first (most basal) suture slightly curved or straight, and dorsally slightly or distinctly diverging from second suture; second and subsequent sutures straight. Lancet almost straight, with dorsal edge slightly concave around apical third, straight on apical third, or slightly rounded throughout, with 19–22 annuli (Fig. 14F, H–J); first ctenidium indistinct or divided into small dorsal and ventral parts; second or second and third ctenidia each divided into dorsal and ventral parts; apical ctenidia separated from or fused with each other, and dorsally extending to or slightly separated from olistheter (Fig. 14H–J); serrulae, except for some basal and apical ones, each anteriorly with tubercle (Figs 11F, 14G–J); middle serrulae each with 15–29 denticles (Fig. 11F) (12th serrulae from apex with 26 denticles in fig. 7 in Togashi, 1958); apical seven to 12 serrulae almost flat (Fig. 14H–J); apical seven to 14 serrulae with denticles lining up without gaps; marginal sensilla of middle and apical annuli funnel-shaped and extending near serrulae, but those of basal one to three annuli usually pore-shaped or very short tubular and apart from serrulae (Fig. 14G). Male genitalia (Figs 11C, 14K, L) with parapenis extremely deformed, divided into lateral and basal sclerites (for these sclerites, see also Fig. 2N), without setae; lateral sclerite located laterally to penis valve, and basal sclerite markedly projecting, apically forming acute angle with opposite basal sclerite; basal ring mostly in contact with basal sclerite of parapenis and apically narrowly rounded; digitus of volsella somewhat shorter than harpe. In penis valve, valviceps about as long as valvura, with apex rounded, dorsal edge markedly convex and ventral edge straight (Fig. 14M).

Immature stages. According to Sasaki (1923), egg about 1.2 mm long and purplish red. Middle instar larvae pale grey, with head black (Fig. 15A). Last feeding instar larva (penultimate instar larva) with head black (Fig. 15B); trunk mat purplish black, ventrally pale grey; thoracic legs pale grey, with apices black. According to Okutani (1959), trunk densely covered with spinules; prothorax with three annulets, mesothorax and metathorax each with four annulets, abdominal segments 1–8 each with six annulets and abdominal segment 9 with five annulets; annulet 2 of prothorax, annulets 1 and 3 of mesothorax and metathorax and annulets 2 and 4 of abdominal segments with large conical warts. Mature larva (ultimate instar larva) with head black, legs gray, and trunk shiny black, slightly with bluish tinge (Fig. 15C).

Material examined. Togashi (1958) wrote “All the types designated in this report are in my collection” for the holotype ♀ (“ Mt. Shiritaka near Tsurugi, Ishikawa Pref., 20. v. 1956, I. Togashi leg”) and the paratypes 2♀ 1♂. Most of his collection is now kept in the NSMT, but we have been unable to find the type specimens there .

Specimens examined: JAPAN: RISHIRI Is.: 1♂, Oshidomari, 25. VI. 1990, A. Shinohara (Figs 12F, 14K–M) (NSMT) . --- HOKKAIDO: 1♀, Ashoro, 17. VI. 1968, T. Naito (NSMT) ; 2♂, Kamishihoro, Nukabira, 14. VI. 1968, T. Naito (Fig. 4D) (NSMT) ; 1♀, Esashi, Utanobori, Kasumi-toge, 22. VI. 2006, A. Shinohara (NSMT) ; 1♂, Nayoro, Nisshin, 44°24’N 142°32’E, 7. VII. 2022, H. Hara (NSMT) ; 1♀ 2♂, Kamikawa, Sounkyo, 19. VI. 1938, K. Sato (NSMT) ; 1♂, same locality, 27. VII. 1951, Takeuchi, J. Kisii (NSMT); 1♀, same locality, 26. VII. 1987, T. Naito (NSMT); 1♀, Kamikawa, Aizankei, 19. VII. 1987, T. Naito (NSMT) ; 1♀, Mts. Daisetsu-zan, 29. VI. 1987, A. Shinohara (NSMT) ; 2♀ 1♂, Higashikawa, Chubetsu Dam, 20. VI. 1997, Y. Nishijima (HU) ; 1♀, Fukagawa, Takadomari, 28. V. – 6. VI. 2007, Malaise trap, H. Hara (NSMT) ; 1♀, Bibai, 11. VI. 1996, H. Hara (Figs 11F, 14F–H) (NSMT) ; 1♂, Bibai, Koshunai, 43°17’N 141°51’E, 24. V. 2015, H. Hara (Figs 4G, 11C) (material of Hara et al. 2021) (NSMT) ; 1♂, Ebetsu, Nopporo, 2. VI. 1929, C. Watanabe (HU) ; 1♂, same locality, 10. VI. 1975, M. Suwa (HU); 1♂, Moiwa, 4. VI. 1905 (material of Matsumura 2012) (HU) ; 1♀, Sapporo, Hitsujigaoka, 43°00’N 141°24’E, 21–28. V. 2003, Malaise trap, K. Konishi (NSMT) ; 1♂, same data but, 28. V. – 4. VI. 2003 (NSMT); 1♂, Sapporo, Hoheikyo, 12. VI. 1979, A. Shinohara (NSMT) ; 1♀, Mt. Soranuma-dake, 3. VII. 1964, A. Nagatomi (Figs 2K, 8A) (NSMT) ; 1♀, Kimobetsu, Nakayama-toge, 42°50’N 141°05’E, 1. VII. 2013, A. Shinohara (NSMT) ; 1♂, Tomakomai, 18. VI. 1992, H. Hamaji (NSMT) ; 1♀, Yakumo, 28. VI. 1932, H. Sugiura (NSMT) . --- HONSHU: Aomori Pref.: 1♀, Rokkasho, Takahoko, 6. VI. 2015, T. Keino (NSMT) ; 1♀, Oma, “Shiotaruishi”, 31. V. 2015, T. Keino (NSMT) . --- Iwate Pref: 1♀, Morioka, Tsunagi-onsen, 3. VI. 1981, T. Tanabe (NSMT) . --- Fukushima Pref.: “ Shiroyama, Asakawa ”, 23. IV. 1950, H. Hasegawa (NSMT) . --- Ibaraki Pref.: 4♀ 3♂, Sakuragawa, Hirasawa, 36°24’N 140°09’E, 19. IV. 2023, H. Hara (Fig. 2B, E) (NSMT) ; 1♀, Toride, Komenoi, 8. V. 1993, H. Hamaji (Fig. 2I) (NSMT) . --- Chiba Pref.: 2♂, Ichikawa, 26. IV. 1960, J. Yoshioka (NSMT) . --- Tochigi Pref.: 1♀, Nasu, Takaku, 20. V. 1995, H. Takizawa (HU) ; 5♂, Nakagawa, Wami, 28. IV. 2009, S. Ibuki (NSMT) ; 2♂, same data but, 5, 6. V. 2010 (NSMT); 2♂, same data but, 1, 8. V. 2012 (NSMT); 1♀, same data but, 22. V. 2012 (NSMT); 1♀, Nakagawa, Wami, 36°45’N 140°09’E, coll. larva on Polygonatum falcatum 5. VI. 2019, mat. 18. VI., em. 6. V. 2020, S. Ibuki (Figs 11A, 14A, B, 15A–C) (NSMT) ; 1♀, same data but, 36°45’N 140°10’E, coll. larva 4. VI. 2015, mat. 7. VI., em. 3. V. 2016 (Fig. 14I), and its progeny, 6♂, from, eggs laid within Polygonatum falcatum 4. V. 2016, larvae hatched 14. V., mat. 30. V., em. 19. IV. 2017 (Fig. 9K) (NSMT) ; 1♀, “KINOMEZAWA” (=? Yaita), 15. V. 1966, T. Saito (NSMT) ; 1♂, Nikko, Kirifuri, 2. VI. 1971, Ishikawa & Kochi (NSMT) ; 3♀, Nikko, Shichiri, 28. IV. 2018, A. Shinohara (Figs 9H, 12B, E, 14E) (NSMT) ; 1♀, same data but, 8. V. 2019 (NSMT); 1♂, Nikko, Higashi-okorogawa, 12. V. 2002, T. Saito (NSMT) ; 1♀, Tochigi, Shiriuchi, 3. V. 1987, T. Saito (NSMT) ; 1♂, same data, 16. IV. 2004 (NSMT); 1♀ 1♂, Sano, Tochimoto, 19. IV. 1987, T. Saito (NSMT) ; 1♀, Sano, Kubocho, 14. V. 1978, T. Saito (NSMT) ; 1♀, “ Mt. Karasawa ”, 14. V. 1978, T. Saito (NSMT) . --- Gunma Pref.: 1♀, Amasakehara, 25. V. 1987, T. Matsumoto (NSMT) . --- Saitama Pref.: 1♂, Ina, 20. IV. – 10. V. 2014, K. Haga (NSMT) ; 1♂, same data but, 19. V. 2015 (NSMT); 1♀, Omiya, 15. V. 1976, T. Nambu (NSMT) ; 1♀, Yorii, “Nakaomaeda”, 19. IV. 1982, M. Uchida (NSMT) ; 1♂, same data but, 21. IV. 1985 (NSMT); 1♀, Ogawa, 26. IV. 1993, K. Haga (NSMT) ; 1♂, Ogawa, Yukie, 1. V. 1993, T. Nambu (NSMT) ; 1♀ 1♂, Ogawa, “ Kasayama ”, 25. V. 1996, T. Nambu (NSMT) ; 1♀, Ogose, 13. V. 1978, T. Nambu (NSMT) . --- Tokyo Met .: 1♀, Takadanobaba, 27. IV. 1991, S. Asahina (NSMT) ; 1♂, Akatsuka, 6. V. 1928, K. Sato (NSMT) ; 1♀, Akasaka Estate, 29. IV. – 13. V. 2003, M. Owada (material of Shinohara 2005) (NSMT) ; 1♀, Meguro, 6. V. 1959, T. Okutani (NSMT) ; 1♂, Kinuta, 11. V. 1932, S. Asahina (NSMT) ; 2♂, same locality, 3. V. 1959, Y. Kurosawa (NSMT); 1♂, same data but, 5. V. 1961 (NSMT); 1♂, Inagi, 18. IV. 1971, T. Saito (NSMT) ; 1♀, V. 1934, Takeuchi, “Obi” (NSMT) . --- Kanagawa Pref.: 1♀ 1♂, “ Mukogaoka ”, 29. IV. 1928, K. Sato (NSMT) ; 1♂, Yokohama, 23. IV. 1928, K. Sato (NSMT) ; 1♀ 2♂, same data but, 26. IV. 1928; 3♀ 3♂, same data but, 5. V. 1930; 1♀, same data but, 5. V. 1954; 1♀ 1♂, Yokohama, Kodukue, 29. IV. 1955, K. Sato (NSMT) ; 1♀, Yokohama, Shinohara-cho, 8. V. 1955, K. Sato (NSMT) ; 1♀ 1♂, Hiyoshi, 12. V. 1971, A. Shinohara (NSMT) ; 1♀, Yokohama, Totsuka, 8. V. 1949, H. Nagase (NSMT) ; 2♀, Kamakura, 13. V. 1951, H. Nagase (NSMT) ; 1♀, Kamakura, Nikaido, 24. IV. 1955, H. Nagase (NSMT) ; 3♀ 2♂, “OHKURA”, 3. V. 1970, T. Saito (NSMT); 1♀, Hakone, Kowakidani, 25. V. 1974, A. Shinohara (NSMT) . --- Yamanashi Pref.: 1♂, “ Daibosatsu ”, 24. V. 1969, T. Saito (NSMT) ; 1♂, Sutama, Masutomi, 9. V. 1971, Y. Yoshikawa (NSMT) ; 1♀, same locality, 29. V. 1993, M. Kubota (Figs 2H, 7C, 14D) (NSMT) . --- Nagano Pref: 1♀ 2♂, Karuizawa, 2. VI. 1932, K. Sato (NSMT) ; 1♀, same locality, 26. V. 2000, T. Nambu (NSMT); 1♀, Mts. Yatsugatake, Minoto, 1800 m, 18–19. VII. 1981, K. Mizuno (NSMT) ; 1♀, Matsumoto, Kamikochi, 1500 m alt., 21–23. VI. 1989, A. Shinohara (NSMT). --- Shizuoka Pref.: 1♂, Kawazu, 13. IV. 1928, K. Sato (NSMT); 1♀, “Tenshokyo”, 1000 m, 24. V. 1989, H. Ishikawa (NSMT); 1♀, Hamamatsu, Miyakoda, 22. IV. 1951, J. Minami (NSMT). --- Ishikawa Pref.: 1♀, Kanazawa, Mitsukouji, 12. V. 1949, Takeuchi (NSMT); 1♀, Hakusan, Mt. Shiritaka-yama, 14. V. 1950, Takeuchi, Togashi. --- Kyoto Pref.: 1♀, Kibune, 15. V. 1941, Takeuchi (probably material of Takeuchi 1950, 1952) (NSMT). --- Nara Pref.: 1♂, Mitsue, Mt. Miune-yama, 28. V. 1994, H. Mizuno (Fig. 14C) (NSMT). --- Osaka Pref.: 1♂, Mt. Kongo-san, 3. V. 1916, Takeuchi (NSMT); 1♂, Mt. Iwawaki-san, 3. V. 1931, Takeuchi (NSMT). --- Hyogo Pref.: 1♀, “Sasayama”, 28. IV. 1952, T. Okutani (NSMT); 1♀, “Sasayama 200 m, E13515 N3505”, 3. V. 1974, T. Naito (Figs 1D, 7E, 8D, 9B) (NSMT); 1♀, “Ookouchi, Ootaike” (=?Kamikawa), 7. V. 1977 (Fig. 6I) (NSMT); 1♂, Shiso, Akasai gorge, 3. VI. 1984 (NSMT); --- Okayama Pref.: 1♀, Shinjo, Nodoro, 28. V. 1995, Y. Okushima (NSMT). --- KYUSHU: Fukuoka Pref.: 1♀, Mt. Hikosan, 18. V. 1961, A. Nakanishi. --- TSUSHIMA Is.: 1♀, Mitsushima, Kechi, 34°15’N 129°17’E, 19. IV. 2025, H. Hara; 2♂, Mitsushima, Okata, 34°15’N 129°17’E, 20. IV. 2025, H. Hara. --- KOREA: 1♀, “Mosanrei” [= Musanryong, Hamgyongbuk-do], 15. VI. 1936, Takeuchi (Fig. 14J) (NSMT).

Distribution. Japan: Shikotan Is. (Sundukov 2017a), Rishiri Is. (new record), Hokkaido (Matsumura 1912 as “ Phymatocerus aterrimus ”, Hara et al. 2021, this study), Honshu (Yano 1932 as Phymatocera aterrima, this study), Awaji Is. (Naito et al. 2004), Shikoku (Togashi 1974), Kyushu (Togashi 1972, this study), Tsushima Is (new record). Korea (Lee et al. 2019, this study). Russia: Sakhalin (Haris 2006).

Shinohara (2014) followed Yoshida (2013) and included Taiwan in the distribution, but as we were unable to find the source, their statements appear to be incorrect.

This species is common and widely distributed in Japan and neighboring areas, but previous distribution records may have been confused with P. membra and P. satoi sp. nov. Reconfirmation of these records will be necessary.

Host plant. Asparagaceae: Polygonatum falcatum A.Gray (Okutani 1959, 1967, this study), Polygonatum odoratum (Mill.) Druce (Sasaki 1923, Takeuchi 1949, 1950, Okutani 1959, 1967) (probably P. odoratum (Mill.) Druce var. pluriflorum (Miq.) Ohwi).

Life history. This sawfly has one generation per year (Sasaki 1923, Okutani 1959, this study). The adults occur from late May to early July in Hokkaido and from middle April to middle May in the lowlands of central Honshu. The female lays several eggs in a vertical line inside the stem (Sasaki 1923, this study). In our rearing experiments, the egg period was 10 days and the larval feeding period was 16 days. The larvae occur in May and June (Sasaki 1923, Okutani 1959, this study). The mature larvae enter into the soil and overwinter (Sasaki 1923, this study).

Remarks. We have not examined the type specimens of P. nipponica Togashi, 1958 . The male of this species can be safely identified by the distinctive male genitalia figured in the original description (figs 1, 2 in Togashi, 1958). However, the holotype is a female, and from the female characters written in the original description, it is impossible to determine which of the three Japanese species (our P. nipponica and two similar species, P. membra and P. satoi sp. nov.) is the same species as the holotype. The original description includes the figures of the female lancet (figs 6, 7 in Togashi 1958), although it is unclear whether the lancet is that of the holotype. Those figures resemble the lancets of our P. nipponica and P. satoi sp. nov. in having apical marginal sensilla long and funnel-shaped (Figs 14H–J, 16H; apical marginal sensilla of P. membra very short funnel-shaped, Fig. 13I). Our P. nipponica has been widely collected throughout Honshu, including the type locality, Mt. Shiritaka-yama, while P. satoi sp. nov. has only been found in Nagano and Saitama Prefectures in central Honshu. Therefore, we believe our identification of P. nipponica is correct.

This species is distinguished from the other nine species of the P. aterrima group mainly by the following characters: Lateral ridge of frontal area indistinct or slightly developed (Fig. 12B); setae on flagellum longer than 1/2 middle width of flagellum 1 in female (Fig. 9H), very long and about as long as 1.5 × that width in male (Fig. 9K); epicnemium entirely glabrous (Figs 2B, 4G), rarely with setae in middle; in hind tarsus, length of plantar lobe of tarsomere 1 about 0.4–0.6 × distance between plantar lobes of tarsomeres 1 and 2 in female; tarsal claws with inner tooth large and distance between apices of apical and inner teeth shorter than depth of concavity between these teeth (Fig. 14D); fore wing with cell 2Rs much longer than cells 1R1 and 1Rs combined in posterior length (Fig. 11A); junction of vein Rs and crossvein 2r-rs distinctly proximally distant from junction of vein Rs and crossvein3rm; dorsum of abdomen distinctly or slightly shiny at least in basal few terga (Figs 12E, F, 14A, C); valvula 3 in lateral view with dorsal margin almost straight (Fig. 14E); lancet almost straight, with 19–22 annuli (Fig. 14F); basal two or three annuli with ctenidia reduced; marginal sensilla of middle annuli funnel-shaped and extending to near serrulae (Fig. 11F); basal sclerites of parapenises combined tapering with acute apex and glabrous (Figs 11C, 14L); penis valve with valviceps about as long as valvura, roundly convex on dorsal edge and straight on ventral edge (Fig. 14M).

Togashi (1958) stated that this species may be easily separated from P. aterrima by the form of the male genitalia and ovipositor sheath, but there is no clear difference between the ovipositor sheaths of the two species in our material.