Ischnus splendens Watanabe, 2019, sp. nov.
Creators: name: Kyohei Watanabe
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Ischnus
Ischnus splendens

description: Ischnus splendens sp. nov.
(Standard Japanese name: Nishiki-togari-himebachi)
(Figs. 1D, E, K, 2F, 3G, 9A–J)
Holotype. KPM-NK 69406, F, JAPAN, Kagoshima Pref., Tokunoshima Is., Tete, Mt. Amagi-dake, 27. III. 2011, K. Watanabe leg.
Paratypes. JAPAN: KPM-NK 69407, F, Chiba Pref., Kamogawa City, Mt. Kiyosumiyama, 26. VII. 2004, K. Kubo leg.; KPM-NK 69408, F, Chiba Pref., Kamogawa City, Mt. Uchiurayama, 21. V. 2005, K. Kubo leg.; KPM-NK 69409, F, Kanagawa Pref., Odawara City, Hayakawa, Shiroganerindo, 23. V. 2015, R. Kaga leg.; KPM-NK 69410, F, Fukuoka Pref., Mt. Tachibana, 13. V. 1976, Y. Kanamaru leg.; KPM-NK 69411, F, Kagoshima Pref., Miyanojyo Town, Mt. Shibisan, 25. V. 2007, T. Maeda leg.; KPM-NK 69412, F, Kagoshima Pref., Yakushima Is., Aikodake, 27-30. III. 2007, T. Yamauchi leg. (MsT); KPM-NK 69413, F, ditto, 2. V. – 10. V. 2007; NIAES, F, Kagoshima Pref., Amamioshima Is., Mt. Yuwandake, 29. IV. 1953, T. Shiraki leg.; NIAES, F, ditto, 3. V. 1953; NIAES, F, ditto, 4. V. 1953; KPM-NK 69414–69416, 2 F & 1 M, Kagoshima Pref., Amamioshima Is., Mt. Yuidake, 27. VII. 2004, H. Makihara leg. (MsT); KPM-NK 69417, F, ditto, 10. VIII. 2004; KPM-NK 69418, 69419, 2 F, ditto, 24. VIII. 2004; KPM-NK 69420, F, ditto, 19. IX. 2004; KPM-NK 69421, F, ditto, 14. X. 2004; KPM-NK 69422–69426, 5 M, Kagoshima Pref., Amamioshima Is., Yamato Vil., Oodana, 3. VI. 2007, K. Watanabe & M. Gunji leg.; KPM-NK 69427, F, ditto, 4. VII. 2011, S. Fujie leg.; KPM-NK 69428–69430, 3 F, ditto, H. Sawada leg.; KPM-NK 69431, M, same locality of holotype, 25–31. V. 2007, K. Watanabe leg. (MsT); KPM-NK 69432–69441, 10 M, Kagoshima Pref., Tokunoshima Is., Tokunoshima Town, Kedoku, 21. V. 2008, K. Watanabe & A. Sakai leg.; KPM-NK 69442, F, same data of holotype.
Description. Female (n=23). Body length 7.5–11.0 (HT: 10.5) mm, covered with silver setae.
Head 0.6 times as long as wide. Clypeus 0.55 times as long as wide, convex, punctate dorsally, smooth ventrally, anterior margin sharp (Figs. 1D, E). Face 0.5–0.55 (HT: 0.5) times as long as wide, mat, covered with punctures. Frons almost flat, sparsely punctate laterally, smooth ventrally, with irregular rugae mediodorsally (Fig. 9F). Occipital carina complete, its lower end joined with hypostomal carina. MSL 1.0–1.1 (HT: 1.0) times as long as BWM. OOL 1.1–1.3 (HT: 1.2) times as long as OD. POL 1.1–1.2 (HT: 1.1) times as long as OD. Antenna with 30–33 (HT: 30) flagellomeres. F1 1.2–1.25 (HT: 1.2) times as long as F2.
Mesosoma polished. Epomia present. Lateral area of pronotum largely covered with longitudinal striae (Fig. 9G), punctate dorsally and ventrally. Notauli distinct and shallow on anterior half of mesoscutum. Mesoscutum covered with transverse or irregular rugae medially. Scutellum slightly convex, punctate, with a few longitudinal striae, its lateral margin with carina except for apex (Figs. 9H, I). Epicnemial carina distinct, its dorsal end not joined with anterior margin of mesopleuron and subalar prominence. Mesopleuron largely covered with irregular rugae (Fig. 9G) except for smooth speculum and longitudinal striation behind subalar prominence. Metapleuron punctate, partly covered with somewhat transversely arranged rugae. Propodeum with anterior transverse carina, lateral section of posterior transverse carina and anterior section of pleural carina (Figs. 9G– I), covered with irregular rugae except for area anterior to anterior transverse carina punctate (Figs. 9H, I). Propodeal apophysis obtuse, lobe-like (Fig. 9G). Propodeal spiracle oval. Fore wing length 6.0–8.5 (HT: 7.5) mm. Areolet large, hexagonal, with sides convergent anteriorly (Figs. 1K, 8B). Nervulus opposite to or slightly based on basal vein (Fig. 9B). Nervellus intercepted posterior to midpoint (Figs. 9B, G). Hind femur 5.8–6.5 (HT: 6.4) times as long as maximum depth in lateral view. Hind TS2: TS1, TS3, TS4 and TS5 = 2.0: 4.1, 1.2, 0.6–0.7 (HT: 0.6) and 1.0.
Metasoma mat. T1 2.0–2.05 (HT: 2.05) times as long as maximum width, with a pair of small triangular teeth at base (Fig. 1F). Median dorsal carina of T1 absent (Fig. 1F). Dorsolateral carina of T1 absent anteriorly, present behind spiracle. T2 0.85–1.05 (HT: 0.9) times as long as maximum width. Ovipositor sheath 0.8–0.85 (HT: 0.8) times as long as hind tibia.Apex of ovipositor as Fig. 3G.
Coloration (Figs. 9A–I). Body (excluding wings and legs) black, except for: clypeus except for all margins, face, all orbits, malar space, ventral area of scape and pedicel, mandible except for apex, palpi, collar, dorsal margin of pronotum, a pair of small spot and a median spot of mesoscutum, scutellum, postscutellum, tegula, subalar prominence, an anterior spot of mesopleuron, a longitudinal stripe of mesopleuron and mesosternum, two spots of metapleuron, a spot of propodeum and posterior band of T1–T8 whitish yellow to yellow; F7– F11 (sometimes also F6, F12 and F13) with a white band; ovipositor reddish brown. Wings hyaline; veins and pterostigma brown except for yellow wing base; base of stigma tinged with yellow. Legs reddish brown, except for: fore and mid coxae, trochanters and trochanteli whitish yellow to yellow; fore and mid tarsi partly tinged with brown; fore and mid coxae black at base; hind coxa black with whitish yellow to yellow markings basodorsally and ventrally; hind trochanter black basally, whitish-yellow to yellow apically; hind trochantellus partly tinged with brown; apex of hind femur, base and apex of hind tibia, hind tibial spurs, base of hind TS1 and TS5 blackish brown. In specimens collected in Honshu and Kyushu sometimes show the following variation: face with a median longitudinal black band; whitish yellow to yellow area of mesosternum and propodeum largely reduced in size and often divided into two or three spots; fore and mid coxae with a conspicuous black spot.
Male (n=18). Similar to female (Fig. 9J). Body length 7.0– 10.5 mm. Face 0.6 times as long as wide. MSL 0.7–0.9 times as long as BWM. F11–F16 (sometimes also F17) with a tyloid. Hind TS2: TS1, TS3, TS4 and TS5 = 2.0: 4.0, 1.3–1.4, 0.7–0.8 and 0.9. T1 2.7–2.75 times as long as maximum width. T2 1.2–1.5 times as long as maximum width. Mesoscutum sometimes without a pair of yellow spot anteriorly. F15–F16 (usually also F14, F17 and F18) with a white band.
Distribution. Japan (Honshu, Kyushu, Yakushima Is., Amamioshima Is. and Tokunoshima Is.).
Etymology. The specific name is from the Latin “splendens ” (splendid), referring to their beautiful body coloration.
Remarks. This species apparently resembles I. bimaculatus Jonathan, 2006 (male unknown), from India in the body with many yellow markings and the frons with a median carina and a few longitudinal striations, but it can be easily distinguished by the following combination of character states: MSL 1.0–1.1 times as long as MSL (0.8 in I. bimaculatus); hind coxa with two yellow markings, one at dorsally and other at anteroventrally (with a single yellow marking dorsally). This species can be easily separable from other Japanese species, I. homonae and I. yezoensis, by the head and mesosoma with many conspicuous yellow markings (no yellow markings in both species).
description: Published as part of Kyohei Watanabe, 2019, Taxonomic and Zoogeographical Notes of Japanese Cryptinae (Hymenoptera, Ichneumonidae), with Description of Five New Species, pp. 81-113 in Bulletin of the Kanagawa Prefectural Museum (Natural Science) 48 on pages 96-98, DOI: 10.5281/zenodo.11205625