Euura itoi ( Okutani, 1955 )

Fu, Yuanzun, Yuan, Yuan, Shen, Qian, Xu, Hao, Ye, Zheng, Guo, Li, Wu, Xiaoliang & Zhao, Yunhe, 2021, Taxonomic Notes and New Distribution and Host Plant Records for Sawflies and Woodwasps (Hymenoptera, Symphyta) of Japan VI, Bulletin of the National Museum of Nature and Science. Series A, Zoology 47 (4), pp. 163-188 : 177-180

Euura itoi ( Okutani, 1955)

Japanese name: Karamatsu-aka-habachi ( Figs. 3H–K , 4O–Y , 5Q –AA, 6D–E, 7E–I)

Pachynematus itoi Okutani, 1955: 98 ; Takizawa, 1957: 17; Pschorn-Walcher and Eichhorn, 1963: 59; Pschorn-Walcher and Zinnert, 1971: 348; Muche, 1974: 86; Verzhutskii, 1981: 211; Xiao et al., 1992: 131; Takizawa, 1994: 341; Park et al., 2007: 2.

l Species ignorata z: Verzhutskii, 1966: 143 (see Pschorn-Walcher and Zinnert, 1971).

Nematus (Pikonema) itoi : Zhelochovtsev, 1976: 82.

Nematus (Larinematus) itoi : Zhelochovtsev and Zinovjev, 1988: 169.

Pikonema itoi : Zinovjev, 1993: 21.

Larinematus itoi : Lacourt, 1999: 152; Lacourt, 2020: 429.

Pachynematus (Larinematus) itoi : Taeger et al., 2010: 438; Macek et al., 2020: 532.

Euura itoi : Shinohara and Hara, 2015: 174; Hara, 2019: 73; Hara, 2020: 89, 350.

Redescription (female and male). Length 6.5– 8.0 mm in female, 5.0– 6.5 mm in male. Red yellow ( Fig. 3H–K ). Female: head capsule black only on ocellar area ( Fig. 4O–R ); antenna black, with flagellomere 1 red yellow ventrally or entirely; thorax dorsally with three large black spots, ventrally black except for narrow or wide dorsal part of mesepisternum ( Fig. 3H–I ); legs black from coxae to femora of fore and middle legs and on most of hind leg; abdomen only darkened on narrow anteromedial part of dorsum and valvula 3. Male: head capsule darkened on medial or most part of frons, medial part of vertex and most of occiput ( Fig. 4V–Y ); antenna red yellow; thorax black except for most of pronotum and tegula ( Fig. 3J–K ); legs darkened on bases of coxae, basal part of fore femur and apical part of hind tarsus, often also on all trochan- ters, basal parts of middle and hind femora and whole hind tarsus; abdomen dorsally darkened except for lateral and apical parts. Wings strongly tinged with brown on basal two thirds; veins brown to black; stigma yellow, darkened on wide base and narrow margins.

Head in dorsal view with length behind eye 0.8–0.9 × eye length in female, 0.6–0.7 × in male ( Fig. 4O, V ); length behind lateral ocellus 3.7–4.3 × length of lateral ocellus in female, 2.8– 3.0 × in male. Frontal area with distinct lateral and anterior ridges ( Fig. 4P, W ); anterior ridge not grooved medially. Distance between eyes at torulus 1.6–1.7 × eye height in female, 1.4– 1.5 × in male ( Fig. 4Q, X ). Area above torulus concave, often with small tubercle ( Fig. 4S ). Narrow ridge around torulus wholly distinct. Paraantennal field normal, covered with setae except for narrow medial margin ( Fig. 3S ). Clypeus very deeply concave angularly or roundly on ventral margin ( Fig. 4Q, X ); depth of ventral emargination 1.4–1.7 × median height of clypeus; clypeus with width 2.7–3.2 × maximum height; maximum height 1.0–1.3 × torulus height. Malar space length 0.8–1.4 × median ocellus width. Antenna length 2.7–3.1 × head width; flagellomere 1 1.0–1.2 × as long as major axis of eye, simple in both sexes ( Figs. 3H–K , 4Y ); flagellomere 2 1.0–1.2 × as long as flagellomere 1. Left mandible 1.1–1.2 × as long as right one, in outer view sharply tapering basally, thin from middle to apex, with middle part slightly thickening towards apex ( Fig. 4T ). Right mandible rather sharply tapering on basal half and gradually narrowing on apical half ( Fig. 4U ). Basal outer surfaces of both mandibles not widely flattened or concave. Maxillary palpus with palpomere 2 0.6– 0.8 × as long as palpomere 3 and palpomere 6 0.6–0.9 × as long as torulus height.

Mesoscutellar appendage length 0.5– 0.9 × minor axis of cenchrus ( Fig. 5Q, Y ). Metascutellum length 1.2–1.6 × minor axis of cenchrus. Mesepisternum with groove along anterior edge extending into epicnemium. Epicnemium with ventral edge distinctly grooved. Katepimeron glabrous, usually narrowly covered with setae posteriorly. Anterior fore tibial spur with velum. Hind tibia usual, 0.7–0.9 × as broad as hind femur in anterior view; posterior hind tibial spur 1.0–1.3 × as long as apical breadth of hind tibia, 0.5–0.7 × as long as hind tarsomere 1. Hind tarsus 0.8–0.9 × as long as hind tibia ( Fig. 3I ). Tarsal claws narrow, with small inner tooth ( Fig. 5R, Z ); depth of concavity between apical and inner teeth about 0.5 × or less distance between these teeth. Fore wing with cell Sc 0.7– 1.2 × as wide as vein C at level of base of vein Rs+M ( Fig. 5S ). Hind wing with section of vein 1A between cell 1A and crossvein cu-a 1.1– 1.4 × as long as crossvein cu-a.

In female abdomen, sternum 7 with posterior margin moderately concave beside median projection ( Fig. 5T ). Tergum 9 normal in size, in lateral view 1.0–1.7 × as long as tergum 8 at level of spiracle 8 ( Fig. 5U ). Cercus 4.0–7.0 × as long as wide, posteriorly extending far beyond valvula 3 ( Fig. 5U, W ). Ovipositor sheath 0.3–0.4 × as long as abdomen, 0.5 × as long as hind tibia ( Fig. 3I ); valvula 3 in lateral view short and wide, almost truncate apically ( Fig. 5U ), in dorsal view roundly convex laterally, truncate apically ( Fig. 5W ). Lance in lateral view with dorsal margin slightly rounded ( Fig. 6D ); radix with subdorsal carina; lamnium with annuli distinctly oblique. Lancet with radix 0.9 × as long as lamnium ( Fig. 6E ); lamnium with 12–13 annuli; basal annuli straight; middle and apical annuli slightly arched; ctenidia absent; ventral margin of lamnium serrate; serrulae with minute denticles.

In male abdomen, tergum 8 with procidentia much protruding posteriorly, nearly rectangle ( Fig. 5 AA) and tergal hollow indistinctly defined. Subgenital plate 0.5 × as long as abdomen, 0.8– 0.9 × as long as hind tibia, gradually narrowing towards apex, with apex narrowly rounded or narrowly truncate. Genitalia with harpe in ventral view longer than wide ( Fig. 7F ); valviceps with many spinules centrally ( Fig. 7G–H ); parapennis acute; valvispina tapering with pointed apex; paravalva not protruding apically.

Head, thorax and abdomen generally smooth and shiny, with punctures minute or inconspicuous. Frons, vertex, pronotum, median mesoscutal lobe and most of abdomen very slightly microsculptured. Mesoscutellar appendage laterally microsculptured. Mesopostnotum microsculptured, with narrow medial part not or slightly microsculptured. Metapostnotum not microsculptured.

Material examined. Holotype of Pachynematus itoi Okutani, 1955 ( Figs. 3H–I , 4O–R , 5Q–V, X ): ˂ with a label written as lSoehi-mura, Nagano-ken, 13-VIII-1955 z and a piece of red paper with nothing written on it. Paratypes of P. itoi : 1 ˂ ( Fig. 6E ) and 1 ˁ ( Fig. 7E–F, H–I ) with the same label as the holotype; 1 ˂ ( Fig. 6D ) and 1 ˁ, lSoehi-mura, Nagano-ken, 13-VIII-1955, [Karamatsu (in Japanese; = Larix kaempferi )]z; 2 ˂ ( Fig. 5W ), lUeda, Nagano-ken, 15-VIII-1955 z; 1 ˁ ( Figs. 3J–K , 4V–Y , 5Y – AA) with a label written as lUeda, Nagano-ken, 15-VIII-1955 z and a piece of red paper with nothing written on it.

The type series of P. itoi mentioned by Okutani (1955) is lHolotype: 1 female, Soehi-mura, Nagano Prefecture, Aug. 13, 1955, T. Ito leg. Allotype: 1 male, Ueda, Nagano Prefecture, Aug. 15, 1955, T. Ito leg. Paratypes: 2 males and 3 females, same data as holotype; 2 females, same data as allotypez. Although there are no specimens with the type label of Pachynematus itoi in Oku- tani`s collection now kept in the National Museum of Nature and Science, Tsukuba, we have found the above five females and three males agreeing with the original description in the museum. The female and male with a piece of red paper are safely considered the holotype and the allotype stated by Okutani (1955), respectively, judging from the figures in the original description (compare Fig. 3H, J with figs. 6, 7 in Okutani, 1955, respectively).

Other material examined. JAPAN: HONSHU: Gunma Pref.: 4 ˂, Mt. Asama-yama , VIII. 1956, Takeuchi. — Nagano Pref.: 1˂, Ueda, em. 21. VI. 1956, K. Ozawa; 4 ˂, Ueda, Sanada-machi, Soehi, mid-VII–late VIII. 1955, host: Larix kaempferi ; 5 ˂5 ˁ ( Fig. 6G ), same locality, V. 1956, Takeuchi (probably reared); 1˂, Chi- kuhoku, Aoki-toge, 29. VI. 1956, T. Ito; 4˂ ( Fig. 3S–U ), Utsukushigahara, 16–17. VIII. 1961, T. Naito; 2˂, Matsumoto, Shimashima, 7. VI. 1929, Takeuchi; 1 ˁ, Kiso-machi, Shinkai, 7. VIII. 1956, T. Ito; 5 ˂, Kiso-machi, Fukushima, em. 28–30. VI. 1956, T. Ito .

Distribution. Japan: Honshu ( Okutani, 1955). Korea ( Park et al., 2007). China ( Xiao et al., 1992). Russia: Magadan Oblast, Siberia, Ural (Zhelochovtsev, 1976; Verzhutskii, 1981). East Europe ( Pschorn-Walcher and Eichhorn, 1963; Pschorn-Walcher and Zinnert, 1971).

Host plants. Pinaceae : Larix decidua Mill. ( Pschorn-Walcher and Eichhorn, 1963), L. gmelinii (Rupr.) Rupr. ( Xiao et al., 1992), L. kaempferi (Lamb.) Carrière ( Okutani, 1955), L. olgensis A. Henry ( Xiao et al., 1992).

Life history and immature stages. See Takizawa (1957, 1994), Pschorn-Walcher and Eichhorn (1963), Verzhutskii (1966, as l Species ignorata z), Pschorn-Walcher and Zinnert (1971) and Park et al. (2007).

Remarks. Euura itoi is distinguished from other species of Euura and similar genera by the following features: head capsule and abdomen almost entirely red yellow in female, predomi- nantly so in male ( Fig. 3H, J ); wings strongly tinged with brown on basal two thirds; stigma yellow, widely darkened basally, narrowly darkened marginally; malar space length 0.8–1.4 × median ocellus width; left mandible longer than right mandible, in outer view with middle part slightly thickening towards apex ( Fig. 4T ); right mandible continuously tapering from base to apex ( Fig. 4U ); maxillary palpus not shortened, with palpomere 2 0.6–0.8 × as long as palpomere 3; mesoscutellar appendage 0.5–0.9 × as long as minor axis of cenchrus ( Fig. 5Q, Y ); in hind leg, tibia narrower than femur in anterior view and tarsus 0.8–0.9 × as long as tibia ( Fig. 3I ); tarsal claws with small inner tooth ( Fig. 5R, Z ); in female, cercus posteriorly extending far beyond valvula 3 and valvula 3 short and apically truncate in dorsal view ( Fig. 5W ); lancet without ctenidia ( Fig. 6E ); in male, procidentia nearly rectangular ( Fig. 5 AA); penis valve with many spinules on center of valviceps ( Fig. 7G–I ).

In the key to species of Pachynematus by Muche (1974), our specimens of E. itoi including the holotype do not go to this species, because all of them have the femora not entirely pale (at least the base of the fore femur is darkened) ( Fig. 3I, K ), the stigma yellow with the wide dark base ( Fig. 3H, I ) and the mesoscutellum widely flat ( Fig. 5Q, Y ). The keys by Zhelochovtsev and Zinovjev (1988), Macek et al. (2020) and Lacourt (2020) do not work either for the reasons stated under the remarks of E. imperfecta above.

Figures

Fig. 3. A–G, L–O, Euura imperfecta: A–B, female, Hokkaido, dorsal and ventral views; C–D, male, Hokkaido, dorsal and ventrolateral views; E–F, female, Honshu, dorsal and ventrolateral views; G, female, Honshu, ven- trolateral view; L, egg, Hokkaido; M, semifinal instar larva, lateral view; N–O, final instar larva, lateral and dorsal views; M–O, Hokkaido, Bibai, 1986. H–K, Euura itoi: H–I, female, dorsal and ventrolateral views; J–K, male, dorsal and ventrolateral views.All photographed by Hara.

Fig. 4. A–N, Euura imperfecta: A–G, female, Hokkaido; H–K, male, Hokkaido; L–N, female, Honshu. O–X, Euura itoi: O–U, female; V–X, male. A, H, L, O, V, Head, dorsal view; B, I, M, P, W, dorsomedial part of head anterodorsal view; C, J, N, Q, X, head, anterior view; D, K, R, Y, head, lateral view; E, S, torulus and its surroundings, anterolateral view; F, T, left mandible, outer view; G, U, right mandible, outer view. All photo- graphed by Hara.

Fig. 5. A–P, Euura imperfecta: A–H, female, Hokkaido; I–K, male, Hokkaido; L–P, female, Honshu. Q–AA, Euura itoi: Q–X, female; Y–AA, male.A, I, Q, Y, Posteromedial part of thorax, dorsal view; B, J, L, R, Z, tar- sal claw, anterior or posterior view; C, S, anteromedial part of fore wing; D, T, apical part of abdomen, ventro- lateral view; E, M, U, abdomen apex, lateral view; F, N, V, ditto, posterolateral view; G, O, W, ditto, dorsal view; H, P, X, ditto, posterior view; K, AA, apical part of abdomen, dorsal view. M–N, P, Ovipositor removed; K, genitalia removed.All photographed by Hara.

Fig. 6. Female ovipositor. A–C, Euura imperfecta: A–B, Hokkaido; C, Honshu. D–E, Euura itoi. A, D, Ovipositor; B–C, E, lancet.All photographed by Hara.

Fig. 7. Male genitalia. A–D, Euura imperfecta, Hokkaido; E–I, E. itoi. A, E–F, Genital capsule: A, ventral view (penis valve removed); E, F, dorsal and ventral views. B–D, G–I, Penis valve, lateral view (left dorsal). All photographed by Hara.