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

description: Syzeuctus apicifer (Walker, 1874)
(Figs 1 A, 2 A, 3 A–E, 4 A–D)
Macrus apicifer Walker, 1874: 305.
Materials examined. JAPAN: 1 F (type of M. apicifer), “Japan. Coll. F. Walker. 1913-71.” (NHMUK); [Hokkaido] 2 F & 2 M, Mt. Muine, 26. VIII. 1968, K. Kusigemati leg. (SEHU); 2 F, Abuta County, Nakayama-pass, 12. VIII. 1979, Y. Seiyama leg. (EUM); [Honshu] 1 M, Akita Pref., Mitane Town, Tonosawa, 10. IX. 2016, J. Kobayashi leg. (KPMNH); 1 F, Fukushima Pref., Aizuwakamatsu City, Seabura-toge, 27. IX. 2007 (KPMNH); 1 F, Tochigi Pref., Kuroiso, Enna-skyline, 13. VII. 2000, E. Katayama leg. (KPMNH); 1 F, Tochigi Pref., Kuroiso Town, Morura, 4. VIII. 2000, E. Katayama leg. (KPMNH); 2 F & 2 M, Tochigi Pref., Nikko City, Yumoto, 22. IX. 2015, J. Okayasu leg. (EUM); 1 F, Saitama Pref., Nagatoro Town, Nagatoro, 8. IX. 2005, M. Uchida leg. (KPMNH); 1 F, Tokyo, Akiruno City, Ninomiya, 1. IX. 2009, K. Watanabe leg. (KPMNH); 1 M, Kanagawa Pref., Atsugi City, Nanasawa, 19. VI. 1997, M. Enju leg. (KPMNH); 1 F, Kanagawa Pref., Fujino Town, Mt. Jinba-yama, 13. IX. 2009, K. Watanabe leg. (KPMNH); 1 F, Nagano Pref., Kiso Town, Shinkai, 5–7. VIII. 2004, S. Motoi leg. (KPMNH); 8 F, Nagano Pref., Ueda City, Sugadaira, 25. VIII. 2022, K. Watanabe leg. (KPMNH); 1 F, Aichi Pref., Kasugai City, Takagi, 22. VIII. 2000, C. Mizuno & M. Suzuki leg., MsT (MU); 1 F, Aichi Pref., Seto City, Johkoji, 20. IX. 2000, C. Mizuno & M. Suzuki leg., MsT (MU); 1 F, Kyoto Pref., Kumihama Town, Kuzunohama, 18. IX. 2007, T. Mita leg. (KPMNH); [Shikoku] 1 M, Ehime Pref., Oda Town, 14. VIII. 1995, E. Yamamoto leg. (EUM); 1 M, ditto, 5. X. 1991 (EUM); 1 F, Ehime Pref., Kumakogen, Yurano, 2. VIII. 2006, E. Yamamoto leg. (EUM); 1 F, Ehime Pref., Kihoku Town, Okufujikawa, 27. IX. 2006, Y. Kawakami leg. (EUM); 1 M, Kochi Pref., Higashitsuno Vil., Chikaraishi, 22. IX. 2002, Y. Kawakami leg. (EUM); [Tanegashima Is.] 1 M, Kagoshima Pref., Nishinoomote, Ohirono, 18. XI. 1986, H. Nagase leg. (KPMNH).
Description. Female (n = 29). Body polished and covered with punctures and silvery setae; length 7.0– 10.5 mm. Setae on head and mesosoma not exceptionally long and erect.
Head 0.6–0.7 × as long as wide. Combined length of clypeus and face 0.95–1.0 × 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 0.65–0.7 × as long as basal mandibular width. Genal carina low ventrally, reaching mandibular base. POL 1.45–1.5 × as long as OD. OOL 1.15–1.5 × as long as OD. Temple weakly roundly narrowed behind eye in dorsal view (Fig. 3 D). Antenna with 42–44 flagellomeres. FL I 4.3–5.0 × as long as maximum depth in lateral view and 1.6–1.75 × as long as FL II. Preapical flagellomere 1.2 × 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, its dorsal end not reaching dorsal margin. Mesopleuron densely punctate; speculum with a small smooth area (Fig. 3 E). Epicnemial carina present latero-ventrally and ventrally, its dorsal end remote from anterior margin of mesopleuron, without angulation (Fig. 1 A). Dorsal surface of propodeum without transverse rugae. Posterior transverse carina of propodeum absent; sometimes obtusely present medially. Fore wing length 5.6–7.25 mm. Areolet receiving vein 2m-cu slightly basal to the outer angle, petiolated anteriorly; petiole longer than areolet (Fig. 3 B). Fore wing vein 1cu-a subvertical, slightly postfurcal to vein M&RS. Nervellus reclivous, intercepted posterior to the middle. Hind femur 5.75–6.4 × as long as maximum depth in lateral view. Ratio of length of first to fifth hind tarsomeres 4.0–4.1: 2.0: 1.4: 0.7–0.75: 0.8–0.85. Hind tarsal claws pectinate by short teeth, moderately bent apically (less than 90°) (Fig. 2 A).
Metasoma. T I 2.0–2.35 × as long as maximum width, finely punctate except for smooth areas on median longitudinal area, area along posterior margin and lateral sides. T II 1.2–1.4 × as long as maximum width, finely and densely punctate. T III to T V coriaceous with fine punctures. Ovipositor sheath 2.5–2.8 × as long as hind tibia, ca. 1.2 × as long as fore wing, and shorter than body length.
Colouration (Figs 3 A–E). Body (excluding wings and legs) black. Clypeus yellow, usually with black area(s). Mandible except for teeth and base, malar space, inner orbit on frons and vertex, outer orbit except for dorsal part yellow. Scape partly narrowly tinged with yellow. Flagellum and palpi largely tinged with reddish-brown. Postero-dorsal corner of pronotum tinged with yellow. Subtegular ridge, tegula, scutellum except for baso-median black area, postscutellum, a pair of antero-lateral spots of propodeum, and a posterior triangle marking of propodeum yellow. Lower part of pronotum and antero-lateral area of mesoscutum usually with a pair of small yellow spots. Metasomal tergites red to reddish-brown except for posterior segments tinged with black; anterior and posterior parts of T I yellow; posterior part of T II with yellow; posterior margin of T III narrowly tinged with yellow. Red 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 except for apical clouded area of fore wing. Veins and pterostigma blackish-brown except for yellowish-brown wing base. Fore and mid legs yellow; coxae with small black spots ventrally; apex of middle tarsus tinged with yellowish-brown. Hind coxa and trochanter black, each with yellow apical margin. Hind trochantellus yellow. Hind femur reddish-brown. Hind tibia yellowish-brown to reddish-brown, usually more or less darkened apically. Hind tibial spurs yellowish-brown. Hind tarsus brown to blackish-brown, base of first tarsomere and apices of each tarsomere usually paler than other parts.
Male (n = 13). Similar to female (Figs 4 A–D). Malar space 0.9–1.0 × as long as basal mandibular width. Antenna with 43–45 flagellomeres. FL I 5.3–5.7 × as long as maximum depth in lateral view and 1.85 × as long as FL II. Tergal spiracles not enlarged. T I 2.4–2.65 × as long as maximum width. T II 1.4–1.55 × as long as maximum width. Yellow area of body more extended than in female. Clypeus, malar space, inner orbit on face, palpi, and postero-ventral spot of mesopleuron yellow. Face usually with yellow longitudinal markings; size of black area varied (Figs 4 C, D).
Distribution. Japan (Hokkaido, Honshu, Shikoku, and Tanegashima Is.), China and Korea. New to Hokkaido and Tanegashima Island.
Bionomics. Host is unknown. Adults usually collected in grassland. In Sugadaira, Nagano Prefecture, many females (including above eight females) came to the flower of Angelica polymorpha Maxim. (Apiaceae).
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 38-40, DOI: 10.11646/zootaxa.5496.1.2, http://zenodo.org/record/13331013