Coelichneumon bivittatus ( Matsumura, 1912 )

Riedel, Matthias & Watanabe, Kyohei, 2021, The genus Coelichneumon Thomson in Japan (Hymenoptera, Ichneumonidae, Ichneumoninae), Zootaxa 4948 (4), pp. 501-545 : 507-509

Coelichneumon bivittatus ( Matsumura, 1912)

Ichneumon bivitatus Matsumura, 1912: 228 , ♂.

Coelichneumon birmanicus Heinrich, 1966: 208–209 , ♀ ♂, syn. nov.

Holotype of I. bivitatus : ♂ “ Ichneumon bivitatus n.sp. det. Matsumura; [red] Type; Kyoto Honshu M. Suzuki; Coelichneumon bivitatus Mats. det. Matsumura ” (Sapporo), type studied. Missing: Tip of right flagellum, left and right 3 rd to 5 th fore tarsomeres, right 2 nd to 5 th mid tarsomeres, both hind tarsi.

Holotype of C. birmanicus : ♀ “N. Burma, Mt. Victoria 1400 m, März / April ” ( ZSM, Munich), type studied.

Non-type material: JAPAN: 1 ♂, Yamanashi Pref., Koufu City, Mitakesyosenkyo , 20. V.1964, H. Suda leg. ; 1 ♂, Fukui Pref., Ohno City, Hatogayu , 3.x.1980, T. Murota leg. ; 1 ♀, Tokyo, Okutama Town, Hikawa , 29.vi.2007, K. Watanabe leg. ; 1 ♀, Saitama Pref., Yorii Town, Gonotsubo , 11.x.2000, T. Nambu leg.

Description: ♀: Body length 15‒21 mm. Flagellum with 41‒44 flagellomeres, lanceolate; 1 st flagellomere 2.3‒2.6× longer than wide, 2 nd flagellomere 2.0‒2.1× longer than wide, combined length 0.57‒0.60× eye length; widest flagellomeres 2.0× wider than long. Temple slightly or moderately and roundly narrowed behin eye. OED 1.1‒1.2× ocellar diameter. Frons smooth ventrally, with transverse rugae or punctures dorsally. Face with dense punctures, smooth; clypeus with scattered punctures, smooth, apical margin slightly extended medially. Gena with scattered punctures ventrally, 1.0‒1.1× wider than eye. MI 0.6‒0.7.

Mesosoma with pale brownish hairs. Notaulus strongly impressed in frontal ¼ of mesoscutum. Mesoscutum densely punctate and finely granulate, but shining, central parts with scattered punctures. Mesopleuron densely punctate, partly rugose-punctate; metapleuron densely rugose-punctate; juxtacoxal carina present. Scutellum slightly elevated, wider than long, without lateral carina, with scattered or rather dense punctures. Area superomedia heart-shaped, about as long as wide, usually confluent with area basalis, rugose; anterior transversal carina caudal to its middle. Area externa with fine rugae and few punctures. Hind coxa with dense punctures and strong scopa in apicoventral ¼. Hind femur 3.8‒3.9× longer than wide, with scattered punctures in ventral ½. 3 rd mid tarsomere 1.5‒1.8× longer than wide. Areolet almost quadrangular, frontal distance between veins 2rs-m and 3rs-m 1× their width; vein 2m-cu distad its middle. Vein 1cu-a postfurcal by 2× its width.

Postpetiolus strongly widened; lateral field 0.7‒1.0× as wide as the median one, punctate; median field with punctures and some longitudinal rugae. 2 nd tergite 1.05× wider than long. Gastrocoelus strongly impressed, smoothened. Thyridium large, transverse, 1.1‒1.2× wider than the interval, interval narrower than meidan field of postpe- tiolus. 2 nd to 4 th tergites densely punctate, shining, 2 nd and 3 rd tergite aciculate medially. 7 th tergite slightly wider than long. Seen from dorsal ovipositor sheath c.0.5× as long as 7 th tergite.

Color: Black. Stripes on flagellomeres 7/8‒14/16, palps, often base of mandible, sides of clypeus, wide facial and frontal orbits, wide triangular spot on vertex, gena and ventral outer orbit, collare and upper margin of pronotum, sometimes two longitudinal stripes on mesoscutum, spot on tegula, subtegular ridge, frontal and sometimes ventral spots on mesopleuron, lateral spots or stripes on scutellum, diffuse apical bands on 2 nd to 5 th sternites, fore and mid coxae frontally, fore and mid trochanters, frontal sides of fore and mid legs, subbasal rings of tibiae, apicoventral spot on hind coxa, sometimes apical margin of hind trochanter, hind tibia except narrow base and apical 0.2 and hind tarsomeres entirely (or except brownish tips) cream-yellow. Hind femur black, yellowish in basal 0.15‒0.25. Wings hyaline, pterostigma black.

♂: Body length 17‒21 mm. Flagellum with 42‒45 flagellomeres; 1 st flagellomere 2.6× longer than wide. Tyloids on flagellomeres 7‒21/22, long-oval, centrally deposited, 0.6× as long as the flagellomeres. Temple strongly and roundly narrowed behind eye. OED 1.1× and OOD 1.1× ocellar diameter. Frons, face and clypeus densely punctate. MI 0.2.

Notaulus distinctly impressed in frontal 1/5 of mesoscutum. Mesoscutum with partly scattered punctures. Mesopleuron with dense punctures; metapleuron densely punctate or rugose-punctate; juxtacoxal carina present. Scutellum wider than long, without lateral carina, with rather dense or scattered punctures. Propodeum rounded. Area superomedia sickle-shaped, wider than long, sometimes confluent with area basalis; anterior transversal carina caudal to the middle. Area externa superficially rugose. Fore metatarsus without distinct apical tooth. Hind femur 4.0‒4.1× longer than wide, with scattered punctures in ventral 1/3. Areolet pentagonal, frontal distance of intercubiti 2× their width, 2 nd recurrent vein in the middle. Nervulus postfurcal by 2× its width.

Lateral field of postpetiolus 0.5‒0.8× as wide as median field, punctate, median field punctate and aciculate. Gastrocoelus strongly impressed. Thyridium transverse, c.1.1× as wide as the interval, the interval narrower than the median field of postpetiolus. 2 nd tergite 1.05× longer than wide. 2 nd to 4 th tergites densely punctate and medially aciculate, shining.

Color: Black. Palps, mandible except teeth, clypeus, face, frontal orbit, wide triangular spot on vertex, gena and outer orbit, scapus ventrally, collare and upper margin of pronotum, propleuron, spot on tegula and subtegular ridge, ventral longitudinal band and hind margin of mesopleuron, caudal spot on mesosternum, two paramedian stripes on mesoscutum, wide sides of scutellum, fore and mid coxae mainly and all trochanters, fore and mid legs except dorsal blackish stripes on femora and tibiae yellow. Hind femur reddish-yellow, black in apical 0.4; hind tibia yellow, black in apical 0.15; hind tarsus completely yellow. 2 nd to 5 th sternites with yellowish apical bands. Wings slightly infuscate. Pterostigma brown to black.

Remark: A comparison of the types of C. bivittatus (Matsumura) and C. birmancius Heinrich showed only slight color differences which are not sufficient to separate these taxa in our opinion. We therefore synonymize both species here.

Distribution: Japan (Honshu and Shikoku) ( Uchida 1935; in this study), China, Myanmar, and Korea ( Yu et al. 2016).