Syzeuctus flavofacialis Kang & Lee, 2020

Watanabe, Kyohei & Riedel, Matthias, 2024, Revision of the genus Syzeuctus Förster, 1869 (Hymenoptera, Ichneumonidae, Banchinae) from Japan, Zootaxa 5496 (1), pp. 35-71 : 49-52

Syzeuctus flavofacialis Kang & Lee, 2020

( Figs 1 E , 2 E–G , 10 A–F , 11 A–C )

Syzeuctus flavofacialis Kang & Lee, 2020 in Kang et al. (2020): 24 .

Materials examined. JAPAN: [Honshu] 1 F, Saitama Pref., Ranzan Town, Sugaya , 7. VIII. 1997, T. Nambu leg. ( NARO) ; 1 M, Saitama Pref., Kawagoe City, Shimoshingashi , 17. VII. 2011, N. Kikuchi leg. ( KPMNH) ; 1 F, Tokyo, Machida, Shichikokuyama , 13. VIII. 1987, S. Saito leg. ( NARO) ; 1 F, Kanagawa Pref., Kawasaki City, Ikutaryokuchi , 30. VIII. 2002, I. Waki leg. ( KPMNH) ; 1 F, Kanagawa Pref., Yokohama City, Enkaizan , 28. VII. 2010, K. Kubo leg. ( ZSM) .

Description. Female (n = 4). Body polished and covered with punctures and silvery setae; length 8.0–9.0 mm. Setae on head and mesosoma not exceptionally long and erect.

Head 0.55–0.6 × as long as wide. Combined length of clypeus and face 1.05–1.15 × 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, with a pair of convexities just above of each anterior tentorial pit. Frons slightly concave, without horns, with a pair of slight convexities. Malar space 0.5 × as long as basal mandibular width. Genal carina low ventrally, reaching mandibular base. POL 1.6–1.75 × as long as OD. OOL 1.0 × as long as OD. Temple weakly roundly narrowed behind eye in dorsal view ( Fig. 10 D ). Antenna with 40–44 flagellomeres. FL I 4.25–4.65 × as long as maximum depth in lateral view and 1.7–1.85 × as long as FL II. Preapical flagellomere 1.0 × as long as maximum width.

Mesosoma coarsely and densely punctate, 1.4–1.45 × 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 area ( Fig. 10 D ). Epicnemial carina present latero-ventrally and ventrally, its dorsal end remote from anterior margin of mesopleuron, without angulation ( Fig. 1 E ). Dorsal surface of propodeum with transverse rugae just in front of posterior transverse carina. Posterior transverse carina of propodeum present and complete. Fore wing length 6.6–7.3 mm. Areolet receiving vein 2m-cu slightly basal to the outer angle, petiolated anteriorly; petiole longer than areolet ( Fig. 10 E ). Fore wing vein 1cu-a subvertical, slightly postfurcal to vein M&RS. Nervellus reclivous, intercepted posterior to the middle. Hind femur 5.2–5.7 × as long as maximum depth in lateral view. Ratio of length of first to fifth hind tarsomeres 4.0: 2.0: 1.4–1.5: 0.7: 0.8–0.85. Hind tarsal claws simple except for minute subbasal teeth, sometimes with a small tooth, strongly bent apically in outer tooth (ca. 90°), moderately bent apically in inner tooth (less than 90°) ( Figs 2 E–G ).

Metasoma. T I 1.5 × as long as maximum width, nearly entirely punctate except for small median longitudinal smooth area. T II 1.05–1.1 × as long as maximum width, densely punctate. T III to T V coriaceous with fine punctures. Ovipositor sheath 2.85–3.15 × as long as hind tibia, ca. 1.1 × as long as fore wing, and shorter than body length.

Colouration ( Figs 10 A–F ). Body (excluding wings and legs) black. Clypeus yellow, usually darkened ventrally. Mandible except for teeth, face except for a median longitudinal black stripe and area around anterior tentorial pits, malar space, inner orbit on frons and vertex, and outer orbit except for dorsal part yellow. Scape and pedicel partly narrowly tinged with yellow. Apical part of flagellum brown. Ventral part of flagellum and palpi largely tinged with reddish-brown. Pronotum except for median longitudinal black stripe yellow. Propleuron except for anterior black marking yellow. Mesoscutum with large M-shaped yellow marking. Subtegular ridge, antero-dorsal and small postero-ventral spots of mesopleuron, tegula, scutellum, postscutellum, a pair of antero-lateral spots of propodeum, and a posterior triangle marking of propodeum yellow.A pair of antero-lateral yellow spots of propodeum sometimes united into a posterior triangle yellow marking of propodeum. T I yellow except for a subapical black stripe. T II to T IV each with yellow or reddish-brown base and yellow posterior margin. Reddish-brown area of metasomal tergites sometimes partly darkened. Membranous parts of metasomal sternites largely yellow. Subgenital plate blackish-brown except of reddish-brown apex. Ovipositor reddish-brown. Wings hyaline. Apical clouded area of fore wing slightly present. Veins and pterostigma blackish-brown except for yellowish-brown wing base. Fore and mid legs yellow except for mid fifth tarsomere black. Hind coxa black with yellow apical part and a dorsal small yellow spot. Hind trochanter black except for dorsal and apical yellow parts. Hind trochantellus yellow. Hind femur reddish-brown, weakly tinged with yellow apically. Hind tibia yellow basally, blackish-brown apically. Hind tibial spurs blackish-brown. Hind tarsus blackish-brown except for median part of first tarsomere, basal parts of second and third tarsomeres, and fourth tarsomere yellowish-brown to yellow.

Male (n = 1). Similar to female ( Figs 11 A–C ). Malar space 0.65 × as long as basal mandibular width. POL 1.8 × as long as OD. OOL 0.8 × as long as OD. FL I 4.8 × as long as maximum depth in lateral view. Tergal spiracles not enlarged. Face entirely yellow. T III to T V largely reddish-yellow.

Distribution. Japan (Honshu) and Korea. New to Japan.

Bionomics. Unknown.

Remarks. Japanese specimens differ from the original description based on Korean specimens ( Kang et al. 2020) in the body size (Japanese at most 9.0 mm, Korean specimen is 10 mm), while we conclude that it is the intraspecific variation. Since Kang et al. (2020) recorded the males of this species with no morphological description, this is the first formal description of the male.

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 10. Syzeuctus flavofacialis Kang & Lee, 2020, female from Japan—A: lateral habitus; B: head, mesosoma, and metasoma, dorsal view; C: head, frontal view; D: head, pronotum, and mesopleuron, lateral view; E: fore wing; F: apical part of hind tibia and hind tarsus.

FIGURE 11. Syzeuctus flavofacialis Kang & Lee, 2020, male from Japan—A: lateral habitus; B: head, mesosoma, and metasoma, dorsal view; C: head, frontal view.