Syzeuctus coreanus Uchida 1928
Creators: name: Watanabe, Kyohei
name: Riedel, Matthias
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Syzeuctus
Syzeuctus coreanus

description: Syzeuctus coreanus Uchida, 1928
(Figs 1 C, 2 C, 6 A–D, 7 A–D)
Syzeuctus coreanus Uchida, 1928: 93.
Materials examined. JAPAN: [Honshu] 1 F, Ibaraki Pref., Nanakai Vil., 25. VIII. 2000, H. Makihara leg. (EUM); 1 M, Saitama Pref., Urayamaguchi, 7. VIII. 1966, T. Nambu leg. (MNHAH); 1 F, Saitama Pref., Hanno City, Nishiagano, 28. VIII. 2010, Y. Saito leg. (KPMNH); 1 F, Kanagawa Pref., Yokohama City, Mine, 1. VIII. 2002, K. Kubo leg. (KPMNH); 1 F, Kanagawa Pref., Yokohama City, Enkaizan, 3. VIII. 2008, K. Kubo leg. (EUM); 1 F, Gifu Pref., Kani, Katabira, 20–26. VIII. 2004, K. Yamagishi leg., MsT (MU); [Shikoku]1 F, Ehime Pref., Odamiyama, Namakusadani, 28. VI. 1998, E. Yamamoto leg. (EUM). KOREA: 1 F (lectotype), Onseri, 25. VII. 1924, T. Kurisue leg. (SEHU).
Description. Female (n = 7). Body polished and covered with punctures and silvery setae; length 6.7–8.4 mm. Setae on head and mesosoma not exceptionally long and erect.
Head 0.6–0.65 × as long as wide. Combined length of clypeus and face 1.0 × facial width. Clypeus matt or polished, dorsally 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 0.8–0.85 × as long as basal mandibular width. Genal carina low ventrally, reaching mandibular base. POL 1.5–1.65 × as long as OD. OOL 0.95–1.1 × as long as OD. Temple weakly roundly narrowed behind eye in dorsal view (Fig. 6 D). Antenna with 38–40 flagellomeres. FL I 4.15–4.4 × as long as maximum depth in lateral view and 1.65–1.75 × as long as FL II. Preapical flagellomere 1.0 × as long as maximum width.
Mesosoma coarsely and densely punctate, 1.5 × as long as maximum height. Pronotum with small smooth area just behind of epomia. Epomia present, short, its dorsal part largely absent. Mesopleuron densely punctate; speculum with a large smooth, weakly concave area (Fig. 6 D). Epicnemial carina present latero-ventrally and ventrally, its dorsal end remote from anterior margin of mesopleuron, without angulation (Fig. 1 C). Dorsal surface of propodeum without transverse rugae. Posterior transverse carina of propodeum present and complete. Fore wing length 5.45–6.0 mm. Areolet receiving vein 2m-cu slightly basal to the outer angle, petiolated anteriorly; petiole as long as areolet (Fig. 6 B). Fore wing vein 1cu-a subvertical, slightly postfurcal to vein M&RS. Nervellus reclivous, intercepted posterior to the middle. Hind femur 5.5–6.6 × as long as maximum depth in lateral view. Ratio of length of first to fifth hind tarsomeres 3.9–4.2: 2.0: 1.35–1.4: 0.7: 0.8. Hind tarsal claws pectinate by short teeth, moderately bent apically (less than 90°) (Fig. 2 C).
Metasoma. T I 2.1–2.5 × as long as maximum width, punctate except for smooth areas on median longitudinal smooth area, area along posterior margin and lateral sides. T II 1.45–1.65 × as long as maximum width, finely and densely punctate. T III to T V coriaceous with fine punctures. Ovipositor sheath 2.35–2.55 × as long as hind tibia, ca. 1.0 × as long as fore wing, and shorter than body length.
Colouration (Figs 6 A–D). Body (excluding wings) yellow. Frons, vertex, and gena except for broad yellow area long orbits, occiput, mandibular teeth, dorso-median black spot and postero-lateral triangular spot of pronotum, median longitudinal spot and U-shaped posterior spot of mesoscutum, axillae, baso-median small spot of scutellum, antero-ventral oblique spot and postero-dorsal curved spot of mesopleuron, W-shaped black marking of propodeum, median small spot of posterior margin of propodeum, base of hind coxa, hind trochanter, T I to T IV except for anterior and posterior margins of each segment, and T V to T VII except for each posterior margin black to blackish-brown. Black spot of scutellum sometimes absent. Scape and pedicel blackish-brown dorsally, yellow ventrally. Flagellum and ovipositor brown to reddish-brown. Yellow parts of metasomal tergites, femora, and tibiae sometimes more or less tinged with reddish-brown. Hind tarsus tinged with brown. Wings hyaline except for weak apical clouded area of fore wing. Veins and pterostigma blackish-brown except for yellowish-brown wing base.
Male (n = 1). Similar to female (Figs 7 A–D). Combined length of clypeus and face 0.85 × facial width. Malar space 0.95 × as long as basal mandibular width. Antenna with 42 flagellomeres. Hind femur 5.35 × as long as maximum depth in lateral view. Tergal spiracles not enlarged. Black areas of body smaller than female.
Distribution. Japan (Honshu and Shikoku), China and Korea. New to Shikoku.
Bionomics. Unknown.
Remarks. The photo of this species in Kang et al. (2020, Fig. 2 B) probably shows S. yamatonis sp. nov. due to a different coloration of mesosoma and hind leg.
description: Published as part of Watanabe, Kyohei & Riedel, Matthias, 2024, Revision of the genus Syzeuctus Förster, 1869 (Hymenoptera, Ichneumonidae, Banchinae) from Japan, pp. 35-71 in Zootaxa 5496 (1) on pages 44-46, DOI: 10.11646/zootaxa.5496.1.2, http://zenodo.org/record/13331013