Syzeuctus sambonis Uchida, 1928

Watanabe, Kyohei & Riedel, Matthias, 2024, Revision of the genus Syzeuctus Förster, 1869 (Hymenoptera, Ichneumonidae, Banchinae) from Japan, Zootaxa 5496 (1), pp. 35-71 : 63-65

Syzeuctus sambonis Uchida, 1928

( Figs 1 J , 2 L , 19 A–E , 20 A–C )

Syzeuctus sambonis Uchida, 1928: 94 .

Materials examined. JAPAN: [Honshu] 1 M, Kanagawa Pref., Kamakura , 26. VII. 1981, H. Nagase leg. ( KPMNH); 1 F, Chiba Pref., Kimitsu City, Minekami Vil., Toyooka, 25. VII. 1962, H. Suda leg. ( KPMNH); 1 F, Chiba Pref., Ichikawa City , Kitakokubun, 4. VII. 2002, H. Suda leg. ( KPMNH) ; 1 F, Nara Pref. , Nara City, Nakamachi, 30. VI. 2011, M. Ito leg. ( ZSM) ; 1 F, Hyogo Pref. , Okawachi Town, Tonomine-kogen, 6. VII. 2003, O. Tominaga leg. ( OMNH) ; 1 M, Hyogo Pref. , Mt. Hyonosen, 7. VIII. 1968, K. Hatta leg. ( EUM) ; 1 F, Hyogo Pref. , Sekinomiya, 17. VII. 1953, Taniguchi leg. ( MNHAH) ; [Izu Isls.] 1 F & 1 M, Tokyo , Miyakejima Is., Tsubota, 30. VII. 2008, H. Makihara leg., MsT, ( KPMNH) ; 1 F & 1 M, Tokyo , Miyakejima Is., Ako, 7–30. VII. 2008, H. Makihara leg., MsT, ( EUM) ; [Shikoku] 1 F, Ehime Pref. , Kumakogen, Yurano, 15. VIII. 2005, E. Yamamoto leg. ( EUM) . KOREA: 1 M (holotype), “Chosen Takano Uchida”, “27/7” ( SEHU) .

Description. Female (n = 8). Body polished and covered with punctures and silvery setae; length 11.5–14.2 mm. Setae on head and mesosoma exceptionally long and erect.

Head 0.55 × as long as wide. Combined length of clypeus and face 1.05–1.1 × facial width. Clypeus smooth except for dorsal margin sparsely punctate, slightly convex in lateral view, without central transverse ridge. Face densely punctate, slightly convex medially in lateral view, without a pair of convexities just above of each anterior tentorial pit. Frons slightly concave, without horns or convexities. Malar space 0.3–0.4 × as long as basal mandibular width. Genal carina lamella-like ventrally, reaching mandibular base. POL 1.5–1.7 × as long as OD. OOL 1.3–1.6 × as long as OD. Temple weakly roundly narrowed behind eye in dorsal view ( Fig. 19 D ). Antenna with 49–53 flagellomeres. FL I 5.0–5.2 × as long as maximum depth in lateral view and 1.9–2.0 × as long as FL II. Preapical flagellomere 1.2 × as long as maximum width.

Mesosoma coarsely and densely punctate, 1.4 × as long as maximum height. Pronotum with small smooth area just behind of epomia. Epomia present, its dorsal end not reaching dorsal margin. Mesopleuron densely punctate; speculum with a large smooth area ( Fig. 19 E ). Epicnemial carina present latero-ventrally and ventrally, its dorsal end close to anterior margin of mesopleuron, with angulation ( Fig. 1 J ). Dorsal surface of propodeum without transverse rugae. Posterior transverse carina of propodeum present and complete. Fore wing length 9.3–10.5 mm. Areolet receiving vein 2m-cu basal to the outer angle, petiolated anteriorly; petiole slightly shorter than areolet ( Fig. 19 B ). Fore wing vein 1cu-a subvertical, slightly postfurcal to vein M&RS. Nervellus reclivous, intercepted posterior to the middle. Hind femur 6.0–6.6 × as long as maximum depth in lateral view. Ratio of length of first to fifth hind tarsomeres 3.8–4.0: 2.0: 1.4: 0.5–0.6: 0.65–0.7. Hind tarsal claws simple except for minute subbasal teeth, sometimes with a small tooth, strongly bent apically (ca. 90°) ( Fig. 2 L ).

Metasoma. T I 2.0–2.05 × as long as maximum width, punctate except for median longitudinal smooth area. T II 1.45–1.5 × as long as maximum width. T II to T V coriaceous with fine punctures. Ovipositor sheath 1.25–1.4 × as long as hind tibia, ca. 0.5 × as long as fore wing, and shorter than body length.

Colouration ( Figs 19 A–E ). Body (excluding wings and legs) black. Clypeus, mandible except for teeth, malar space, face except for area around anterior tentorial pits and a median longitudinal spot, inner orbit on frons and vertex, small stripe of outer orbit, and palpi yellow. Antenna blackish-brown to reddish-brown except for small yellow markings of scape and pedicel. Dorsal longitudinal stripe of pronotum, subtegular ridge, scutellum except for a median black spot, postscutellum, and posterior transverse marking of propodeum yellow. Mesoscutum usually with a median small yellow spot. Posterior margins of each metasomal tergites and bases of T III and T IV tinged with reddish-brown to red. Reddish-brown area of metasomal tergites sometimes enlarged. Metasomal sternites blackish-brown except for median parts of membranous parts and posterior margin of subgenital plate tinged with yellowish-brown. Ovipositor reddish-brown. Wings hyaline. Fore wing without conspicuous apical clouded area of fore wing. Veins and pterostigma blackish-brown except for yellowish-brown wing base. Fore and mid legs yellow except for black mid coxa; fore coxa with small black spots. Hind leg black to blackish-brown. Apex of femur and base of tibia tinged with yellowish-brown.

Male (n = 4). Similar to female ( Figs 20 A–C ). Tergal spiracles not enlarged. T II 1.38–1.5 × as long as maximum width. Face entirely yellow. Hind tibia paler than female. Antero-lateral part of mesoscutum sometimes with a pair of small yellow spots.

Distribution. Japan (Honshu, Miyakejima Is., and Shikoku), China and Korea. New to Miyakejima Island.

Bionomics. Unknown.

Remarks. Iwata (1958, 1960) described the ovarian eggs and ovary.

Figures

FIGURE 1. Epicnemial carina of Japanese species of Syzeuctus spp., females—A: S. apicifer (Walker, 1874); B: S. brevicaudus sp. nov. (holotype); C: S. coreanus Uchida, 1928; D: S. flavitarsis sp. nov. (paratype); E: S. flavofacialis Kang & Lee, 2020; F: S. laoticus Riedel, 2022; G: S. maculatus Sheng, 2009; H: S. nigrus sp. nov. (holotype); I: S. rufiapicalis sp. nov. (holotype); J: S. sambonis Uchida, 1928; K: S. takaozanus Uchida, 1928; L: S. yamatonis sp. nov. (holotype).

FIGURE 2. Hind tarsal claws and metasomal tergites of Japanese species of Syzeuctus spp., females (A-N) and males (O–S)— A: S. apicifer (Walker, 1874); B: S. brevicaudus sp. nov. (holotype); C: S. coreanus Uchida, 1928; D, O: S. flavitarsis sp. nov. (holotype); E–G: S. flavofacialis Kang & Lee, 2020; H: S. laoticus Riedel, 2022; I: S. maculatus Sheng, 2009; J: S. nigrus sp. nov. (holotype); K, P, Q: S. rufiapicalis sp. nov. (K: holotype; P, Q: paratype); L: S. sambonis Uchida, 1928; M: S. takaozanus Uchida, 1928; N, R, S: S. yamatonis sp. nov. (N: holotype; R, S: paratype)—A–E, G–N: outer claw; F: inner claw; O, P, R: T I and T II, lateral view; Q, S: T I and T II, dorsal view.

FIGURE 19. Syzeuctus sambonis Uchida, 1928, females from Japan—A: lateral habitus; B: head, mesosoma, wings, and metasoma, dorsal view; C: head, frontal view; D: head, dorsal view; E: pronotum and mesopleuron, lateral view.

FIGURE 20. Syzeuctus sambonis Uchida, 1928, males from Japan—A: lateral habitus; B: head, mesosoma, and metasoma, dorsal view; C: head, frontal view.