Coelichneumon dubius ( Tischbein, 1876 )

Riedel, Matthias & Watanabe, Kyohei, 2021, The genus Coelichneumon Thomson in Japan (Hymenoptera, Ichneumonidae, Ichneumoninae), Zootaxa 4948 (4), pp. 501-545 : 520-521

Coelichneumon dubius ( Tischbein, 1876)

Ichneumon dubius Tischbein, 1876: 275 , ♀ ♂. Types lost ( Riedel 2012: 1518).

Ichneumon periscelis Wesmael, 1845: 32 , ♀ ♂, preoccupied.

Holotype of I. periscelis : ♀ “91; Monografie Exempl. décrit; Ichneumon periscelis Gr. ♀ dét. C. Wesmael” (Brus- sels), type studied.

Non-type material: JAPAN: 1 ♀, Nagano Pref., Outaki Vil., Mt. Outake, Mt. Hakkaisan , 1650–1850 m alt., 35.867°N 137.517°E, 30.vii.2012, S. Fujie leg. ; 1 ♀, Tottori Perf., Daisen Town, Mt. Daisen , 35.2239°N 133.3132°E, 800–1000 m alt., 15.viii.2011, K. Watanabe leg. ; 1 ♀, Toyama Pref., Toyama City, Arimine, Jurodani , 1120 m, 28.vii.–4.viii.2009, M. Watanabe et al. leg., MT ; 1 ♀, ditto, 4–11.viii.2009 ; 1 ♀, Tochigi Pref., Nasushiobara City, Shiobara, Utou-sawa , 700 m, 22–28.v.2008, T. Matsumura leg., MT .

Description: ♀: Body length 12‒18 mm. Flagellum with 40‒43 flagellomeres, slightly lanceolate; 1 st flagellomere 2.4‒2.5× longer than wide; 2 nd flagellomere 2.3‒2.4× longer than wide, combined length 0.52‒0.58× eye length; 8 th to 10 th flagellomeres square, widest flagellomeres c.1.4‒1.7× wider than long. Temple moderately and roundly narrowed behind eye. OED 1.0‒1.3× ocellar diameter. Face densely punctate and granulate. Clypeus densely punctate, smooth between punctures. Gena with very scattered punctures ventrally, laterally 0.9‒1.1× as wide as eye. MI 0.5.

Mesosoma with pale brownish hairs, often with ± smoothened punctures Lateral field of mesoscutum rather superficially punctate and granulate. Mesopleuron with coarse punctures. Metapleuron punctate, partly granulate. Scutellum slightly longer than wide, with punctures, without lateral carina. Area superomedia heart-shaped, slightly wider than long, smoothened, anterior transversal carina caudal to the middle. Area externa with smoothened structure, partly finely striate. Hind coxa densely punctate, without scopa. Hind femur 3.4‒3.8× longer than wide, with scattered punctures in ventral 1/3. 3 rd mid tarsomere 1.6‒1.8× longer than wide. Areolet almost quadrangular, frontal distance between veins 2rs-m and 3rs-m 1× their width; vein 2m-cu slightly distad its middle. Vein 1cu-a postfurcal by 2× its width.

Postpetiolus moderately widened, lateral field 0.4‒0.8× as wide as median field, the latter with fine striae and partly punctate. Thyridium oblique, 1.0‒1.3× wider than the interval. 2 nd tergite 1.1× wider than long; 2 nd and 3 rd tergites superficially punctate, partly granulate, with fine longitudinally rugose medially. 7 th tergite c.1.5× wider than long. Seen from dorsal, ovipositor sheath 0.5× as long as 7 th tergite.

Color: Black. Ivory are stripes on flagellomeres 8‒12/13, often narrow frontal orbit, spot on vertex, sometimes small spots on fore and mid coxae, rarely spot on subtegular ridge and subbasal rings of all tibiae. Wings hyaline; pterostigma brown to black.

♂: Body length 13‒17 mm. Flagellum with 41‒42 flagellomeres; 1 st flagellomere c.2.2× longer than wide. Tyloids on flagellomeres 6/7‒16/17, linear, 0.7× as long as their flagellomeres. Temple strongly and almost linearly narrowed behind eye. OED 0.8‒1.0× ocellar diameter. Gena 0.7× as wide as eye. MI 0.2. Scutellum about as long as wide, with lateral carina in basal 0.3. Area superomedia sickle- or heart-shaped, wider than long. Fore metatarsus with blunt apical tooth. Hind femur 3.7‒3.8× longer than wide. 2 nd tergite c.1.1× longer than wide. 2 nd to 4 th tergites densely punctate, aciculate medially.

Color: Black. Ivory are palps, mandible medially, labrum, clypeus, face, frontal orbit, spot on vertex, outer orbit ventrally, scapus ventrally, sometimes flagellum ventrally and apically, collare and hind edge of pronotum, subtegular ridge, spot on tegula, sometime postero-apical edges of scutellum, often posterolateral spots on postpetiolus (rarely also on 2 nd tergite). Legs black, spots on fore and mid coxae, fore and mid trochanters and trochantelli (sometimes also the hind ones), subbasal rings of all tibiae, frontal stripes on fore and mid legs and sometimes hind tarsus distally. Pterostigma blackish.

Distribution: Japan (Hokkaido and Honshu) ( Uchida 1926 and Nakaya 1998 as C. periscelis ). Iwata (1960) recorded this species from Miyazaki Pref., Kyushu, while we found no voucher specimen. This species has a transpalaearctic distribution.