Coelichneumon caerulogaster, Riedel & Watanabe, 2021

Riedel, Matthias & Watanabe, Kyohei, 2021, The genus Coelichneumon Thomson in Japan (Hymenoptera, Ichneumonidae, Ichneumoninae), Zootaxa 4948 (4), pp. 501-545 : 509-511

Coelichneumon caerulogaster nov. sp.

( figs 1a–d )

Holotype: ♀, JAPAN, Tochigi Pref., Nasusiobara City, Numappara , light trap, 24.vi.2010, K. Suemoto leg. (Kanagawa).

Paratypes: JAPAN: 1 ♀, Hokkaido, Yubari City, Oyubari Natural forest , 43°00´N / 142°04´E, 180 m alt., 31.viii.–13.ix.2007, A. Ueda leg., MT ; 1 ♂, Hokkaido, Shintoku Town , Tomurauski, N 43.27/E142.52, 664–800 m alt., 23.vi.2017, K. Watanabe leg. ; 1 ♂, Tochigi Pref., Kuriyama Vil., Kinunuma , 19.vii.–1.viii.2004, M. Makihara leg. MT ; 1 ♀, Toyama Pref., Toyama City, Arimine, Inonedani , 1120 m alt., 21.Jul–28.Jul 2009, M. Watanabe et al. leg., MT ; 1 ♀, Nagano Pref., Hara Vil. , 21–22.vi.2000, A. Shimizu leg. ; 1 ♂, Nagano Pref., Kawakami Vil. , Azu- sayama, N 35.37/E 138.41,1355– 1455 m alt., 14.vi.2015, K. Watanabe leg. (all Kanagawa and coll. Riedel) ; 1 ♂, Nagano Pref., Kawakami Vil., Azusayama , 35°57´N 138°41´E, ca. 1360–1460 m alt., 14.vi.2015, S. Shimizu leg. (Sapporo) .

Description: ♀: Body length 14‒15 mm. Flagellum strongly lanceolate, with 36‒39 flagellomeres; 1 st flagellomere (without anellus) 2.3× longer than wide, 2 nd flagellomere 2.0× longer than wide, combined length c.0.58× eye length, 9 th flagellomere square, flagellum beyond the middle attenuated and strongly widened, widest flagellomeres 2.0‒2.5× wider than long. Temple rather short, strongly and roundly narrowed behind the eye. OED 1.0× and OOD 0.9× ocellar diameter. Frons and vertex with smoothened surface structure, with fine rugae and rather dense punctures. Face densely punctate, granulate centrally, sides smooth and shining. Clypeus with scattered punctures, smooth and shining. MI 0.6. Gena rather narrow, c.0.75× as wide as eye, with very scattered punctures ventrally. Genal carina reaching hypostomal carina away from mandibular base.

Mesosoma covered with pale brownish hairs. Notaulus impressed in frontal 1/5 of mesoscutum. Mesoscutum with dense punctures, finely granulate but shining. Mesopleuron with coarse punctures; speculum large, smooth and shining. Metapleuron with rather dense punctures; juxtacoxal carina strong. Scutellum slightly, longer than wide, without lateral carina, with scattered punctures. Propodeum short, rounded. Area superomedia slightly elevated, sickle-shaped, about 2× wider than long, with finely rugose surface, sometimes confluent with area basalis; anterior transversal carina caudal to its middle. Area externa with scattered punctures and some fine rugae. Hind coxa densely punctate, with brownish scopa (length 1/5‒2/5 of coxal length). Hind femur 3.7‒4.2× longer than wide, with scattered punctures in ventral half. Tarsi slender 3 rd mid tarsomere 1.6× longer than wide. Areolet pentagonal, frontal distance between veins 2rs-m and 3rs-m 2× their width; vein 2m-cu in its middle. Vein 1cu-a postfurcal by 2× its width.

Metasoma strongly oxypygous. Lateral field of postpetiolus punctate, c.0.6× as wide as middle field, the latter with some coarse striae and rugose punctures. 2 nd tergite 1.05× wider than long. Gastrocoelus strongly impressed. Thyridium slightly oblique, 1.3× wider than the interval; interval narrower than median field of postpetiolus. 2 nd to 4 th tergites densely punctate and granulate; 2 nd and 3 rd tergites aciculate medially; 5 th tergite with superficial punctures, more or less shining. 7 th tergite 1.5× wider than long. Seen from dorsal ovipositor sheath 0.4‒0.7× as long as 7 th tergite.

Color: Black. Metasoma black, with strong bluish shine. Ivory are stripes on flagellomeres 8‒11, sometimes small spot on facial orbit opposite to antenna, narrow stripe of frontal orbit, often spot on vertex, sometimes collare and hind edge of pronotum, sometimes spot on subtegular ridge. Legs black; sometimes spots on fore and mid coxae yellow; apical spots on fore and mid femora and frontal side of fore tibiae yellowish; fore tarsus brownish; subbasal stripes or rings of all tibiae yellow. Wings hyaline, pterostigma black.

♂: Body length 16‒18 mm. Flagellum with 39‒40 flagellomeres, 1 st flagellomere 2.2× longer than wide. Tyloids on flagellomeres 6‒14/15, small and oval, centrally situated, maximally 0.4× as long as the flagellomeres. Temple strongly and almost linearly narrowed behind eye. OED 1.1‒1.2× and OOD 1.0× ocellar diameter. Frons rugose-punctate. Face densely punctate. Clypeus and gena with rather dense punctures, gena c.0.8× as wide as eye. MI 0.2.

Notaulus distinct in frontal 1/3 of densely punctate, partly striate; metapleuron coarsely rugose-punctate; juxtacoxal carina present. Scutellum moderately elevated and about as long as wide, with lateral carina in basal 0.5, with dense punctures. Area superomedia slightly elevated above surrounding areas, horseshoe-shaped, slightly wider than long; anterior transversal carina in its middle. Area externa punctate, with some fine striae. Fore metatarsus with strong apical tooth. Hind femur with dense strong punctures, 4.2‒4.3× longer than wide. Areolet almost quad- rangular, frontal distance between veins 2rs-m and 3rs-m 1× their width; vein 2m-cu distad its middle. Vein 1cu-a postfurcal by 3× its width.

Lateral field of postpetiolus c.0.6× as wide as the median field, the latter with c.15 strong striae. Thyridium oblique, 1.2× as wide as the interval; interval about as wide as median field of postpetiolus. 2 nd tergite 1.15‒1.2× longer than wide. 2 nd to 4 th tergites densely punctate and aciculate medially; 5 th tergite with superficial punctures and some aciculation basally.

Color: Black. Metasoma with weak bluish shine. Stripes on flagellomeres 11‒14, palps ±, labrum, side of clypeus, wide facial orbit, small spot on vertex, hind edge of pronotum, sometimes spot on tegula, sometimes spot on subtegular ridge and small posterolateral spots on scutellum and postpetiolus yellow. Legs black; fore femur frontally, mid femur apically and fore and mid tibiae and tarsi yellowish to ochreous. Hind tibia black, usually with diffuse subbasal reddish or yellowish ring or stripe; hind tarsus ochreous or yellowish. Wings slightly yellowish, pterostigma dark reddish-brown.

Etymology: The specific name refers to the distinct bluish shine of the metasoma.

Distribution: Japan (Hokkaido and Honshu).

Figures

FIGURES 1a–d. Coelichneumon caerulogaster nov. sp.: a. dorsal habitus (holotype: HT), b. head from dorsal (HT), c. propodeum (HT), d. basal tergites (HT).