Ichneumon thyridiator, Riedel, 2018

Riedel, Matthias, 2018, Contribution to the Siberian species of Ichneumon LINNAEUS (Hymenoptera, Ichneumonidae, Ichneumoninae), Linzer biologische Beiträge 50 (2), pp. 1509-1562 : 1531

Ichneumon thyridiator nov.sp. ( figs 18 , 62 , 81 )

M a t e r i a l e x a m i n e d: Holotype: ♀ " Russia, E Siberia, lake Baikal near Anghasolka, 6 iv 2007, leg. Berlov" "under bark of dead Pinus silvestris" (coll. Riedel). Paratype: ♀, with similar labels (coll. Riedel).

D e s c r i p t i o n: Body length 10 mm. Antenna strongly lanceolate, with 32 flagellomeres; 1 st flagellomere 2.0x longer than wide, c.8 th flagellomere square, widest flagellomeres c.0.6x as long as wide; preapical flagellomere about square. Temple strongly and roundly narrowed apically. OOD 1.6. Frons coarsely rugose-punctate. Face densely punctate and finely granulate. Clypeus with scattered punctures, smooth and shining between punctures. Gena c.0.9x as wide as eye, with dense coarse punctures in ventral 1/2, striate-punctate dorsally. Malar space 1.0x as long as width of mandibular base and 0.8x as long as 1 st flagellomere. Genal carina complete, hypostomal carina slightly elevated.

Mesosoma covered with pale brownish hairs. Mesoscutum densely punctate and granulate, ± opaque. Mesopleuron and metapleuron coarsely rugose-punctate; coxal carina present. Scutellum slightly elevated, with dense punctures and lateral carina in basal 0.2. Area superomedia rectangular, c.1.2x wider than long; costula absent. Area petiolaris bordered laterally with irregular rugae in apical half. Hind coxa densely punctate and granulate, without scopa. Hind femur 3.6x longer than wide, with dense punctures. Hind tibia without denticular spurs apico-externally. Tarsomeres slender, 3 rd mid tarsomere c.1.8x longer than wide.

Metasoma strongly oxypygous, hypopygium short. Postpetiolus strongly widened, medi- an field with strong aciculation and some fine punctures. 2 nd tergite 0.78x as long as wide. Gastrocoelus impressed, with several ridges; thyridium slightly oblique, very wide, c.3.0x wider than the interval. 2 nd and 3 rd tergites with fine dense punctures, finely granulate, 2 nd tergite with longitudinal rugosity medially. Ovipositor sheath extending behind metasomal apex. Color: Black. Flagellomeres 7-13 and large spots on 6th and 7th tergites ivory. Mesosoma black, tegula reddish-brown or black. 2 nd tergite mainly red, gastrocoelus darkened; sides of 3 rd tergite reddish basally. Legs black; hind trochantellus completely and hind femur narrowly reddish at base; fore and mid femora apically and fore and mid tibiae and tarsi ± reddish; hind tibia reddish, infuscate in apical 1/3; hind tarsomere reddish-brown, with darkened tips. Wings almost hyaline; pterostigma ochreous.

Males unknown.

T a x o n o m i c a l r e m a r k:ThisnewspeciesbelongstogroupIsensuHILPERT (1992) and runs to Ichneumon boreellus THOMSON in his key. It can be differentiated by the black pronotum, black postpetiolus and 3 rd tergite and slenderer 1 st flagellomere.

Figures

Figs 17-18: Habitus of: (17) Ichneumon scopator nov.sp.; (18) I. thyridiator nov.sp.

Figs 61-62: Scutellum and propodeum of: (61) Ichneumon scopator nov.sp.; (62) I. thyridiator nov.sp. Figs 63-64: Postpetiolus and 2nd tergite of: (63) Ichneumon altaicurtulus nov.sp.; (64) I. berlovi nov.sp.

Figs 81-82: (81) Ichneumon thyridiator nov.sp.: Postpetiolus and 2nd tergite; (82) Ichneumon orientopodius nov.sp.: Moderately elongated hypopygium.