Ichneumon mandibulatus, Riedel, 2018

Riedel, Matthias, 2018, Contribution to the Siberian species of Ichneumon LINNAEUS (Hymenoptera, Ichneumonidae, Ichneumoninae), Linzer biologische Beiträge 50 (2), pp. 1509-1562 : 1521-1522

Ichneumon mandibulatus nov.sp. ( figs 8 , 29 , 43, 52, 71)

M a t e r i a l e x a m i n e d: Holotype: ♀ "S Siberia, Hakassia reg., Sallyghen-Taiga mt. reg., 2400 m, 10 vii 2005, leg. Osipov " (coll. Riedel).

D e s c r i p t i o n: Body length 13.5 mm. Antenna stout and almost filiform, with 36 flagellomeres; 1 st flagellomere 1.5x longer than wide, 4 th flagellomere square, widest flagellomeres c.0.68x as long as wide; preapical flagellomere 0.65x as long as wide. Temple moderately and roundly narrowed behind eye. Ocelli rather small, OOD 1.8. Occiput densely and coarsely punctate and granulate. Frons coarsely rugose-punctate. Face densely punctate, smooth between punctures. Clypeus with rather dense punctures, smooth between punctures. Mandible thickened, with parallel sides, teeth blunt, lower tooth much smaller than the upper one. Gena strongly widened ventrally, 1.5x as wide as eye, with scattered punctures in ventral 1/2. Malar space 1.0x as long as width of mandibular base and 1.3x as long as 1 st flagellomere. Genal carina complete, not interrupted ventrally; hypostomal carina narrow.

Mesosoma covered with brownish hairs. Mesoscutum densely punctate, smooth between punctures. Mesopleuron and metapleuron coarsely striate-punctate; coxal carina present. Scutellum slightly elevated, about as wide as long, with scattered punctures. Area superomedia trapezoid, widest frontally, c.1.2x longer than wide; costula weakly indicated. Area petiolaris without lateral border. Hind coxa coarsely punctate, without scopa, but with a longitudinal blunt ventro-internal edge (as in Ichneumon stramentarius GRAVENHORST ). Hind femur 3.4x longer than wide, with scattered punctures in ventral 1/3. Hind tibia with c.2 denticular spurs apico-externally. Tarsomeres slender, 3 rd mid tarsomere c.1.55x longer than wide.

Metasoma oxypygous, hypopygium short. Postpetiolus strongly widened, lateral field punctate and c.0.9x as wide as the median one, median field with fine regular aciculation. 2 nd tergite c.0.6x as long as wide. Gastrocoelus rather weakly impressed, with several ridges; thyridium transverse, c.0.7x wider than the interval. 2 nd and 3 rd tergites with fine dense punctures, granulate and ± opaque; 2 nd tergite with fine longitudinal rugosity medially. Ovipositor sheath slightly extending behind metasomal apex.

Color: Black. Flagellomeres 5-13 with reddish-yellow ring. Mandible centrally, collare and tegula partly red. Scutellum ivory. 2 nd and 3 rd tergites red; 5 th tergite with a small and 6 th and 7 th tergites with larger ivory spots. Coxae and trochanters, mid trochantellus, basal 2/3 of mid femur and hind femur except narrow red base blackish. Legs otherwise red; hind tibia diffusely yellowish subbasally. Wings with yellowish tint, pterostigma reddish.

Males unknown.

T a x o n o m i c a l r e m a r k Due to the edge on hind coxa, the new species belongs to group E 4 sensu HILPERT (1992) and runs to Ichneumon rufigena KRIECHBAUMER in his key. It differs by the parallel-sided thick mandible, trapezoid area superomedia and black head.

If one neglects the form of hind coxa, it runs to group G 4 sensu HILPERT (1992) and here to Ichneumon jugicola HEINRICH in his key. It can be differentiated by the form of mandible and the ventrally widened gena.

Figures

Figs 5-8: Habitus of: (5). Ichneumon hakassiacus nov.sp.; (6) I. inquinatops nov.sp.; (7) I. lanceolator nov.sp.; (4) I. mandibulatus nov.sp.

Figs 27-32: Head from dorsal of: (27) Ichneumon inquinatops nov.sp.; (28) I. lanceolator nov.sp.; (29) I. mandibulatus nov.sp.; (30) I. mesonotator nov.sp.; (31) I. nigrostigmaticus nov.sp.; (32) I. orientopodius nov.sp.