Virgichneumon perversus (KRIECHBAUMER, 1893)

Riedel, Matthias, 2024, The genus Virgichneumon HEINRICH in the West Palaearctic region (Hymenoptera, Ichneumonidae, Ichneumoninae), Linzer biologische Beiträge 56 (1), pp. 149-199 : 171-172

Virgichneumon perversus (KRIECHBAUMER, 1893) (figs 13, 35, 55, 72)

Holotype: (♀) 19; I. perversus m.; [rot] Holotypus Ichneumon perversus, DILLER 1976 ( ZSM), type studied.

D e s c r i p t i o n: ♀. Body length 8.5-10.0 mm. Flagellum with 34-37 segments, moderately lanceolate; 1 st flagellar segment 2.0-2.3× as long as wide; 10 th segment square; widest segments 1.3-1.5× as wide as long. Temple slightly and roundly narrowed behind eye (fig. 13). OED 1.2-1.4× and OOD 1.5× ocellar diameter. Face with rather dense punctures, clypeus with sparse punctures. Gena with very sparse punctures ventrally, about as wide as eye. MI 1.0. Genal carina reaching hypostomal carina close to mandibular base, hypostomal carina slightly elevated.

Notaulus impressed in frontal 0.2 of mesoscutum. Epicnemial carina moderately elevated behind fore coxa. Mesoscutum, mesopleuron and metapleuron with rather dense punctures, smooth and shining between punctures. Scutellum as wide as or slightly wider than long, with sparse punctures and with lateral carina in basal 0.2-0.3. Area superomedia heart-shaped, wider than long or longer than wide; in or posterior to its middle with costula (fig. 35). Hind coxa densely punctate, without scopa. Hind femur densely punctate, 3.4-3.6× as long as wide. External surface of hind tibia with several (6- 7) denticular spines.

Postpetiole without or with weak latero-median carina, punctate; median field slightly elevated, densely punctate. Gastrocoelus almost rectangularly impressed, smooth, sometimes confluent medially. Thyridium slightly oblique, 0.5× as wide as interval between thyridia (fig. 55). 2 nd tergite 1.2× as wide as long. 2 nd to 4 th tergites densely punctate, smooth and shining between punctures. Ovipositor sheath slightly extending beyond metasomal apex.

Color: black. Setae of mesoscutum grey. Flagellar segments 7/9-13 dorsally, sometimes spot on orbit at antennal grooves, spot of frontal orbit opposite to lateral ocellus, collar, spot of subtegular ridge, apical spot of scutellum and wide apical spots on 6 th and 7 th tergites ivory. Clypeus sometimes reddish laterally. Often petiole apically, postpetiole and 2 nd to 3 th tergites entirely and 4 th tergite basally or ± completely red, following tergites black. Coxae and trochanters black. Legs otherwise red; fore and mid femora ± darkened dorsally; hind tibia slightly infuscate apically; mid and hind tarsi reddish-brown. Pterostigma ochreous or brown.

♁. Body length 10.0- 10.5 mm. Flagellum with 36 segments; 1 st flagellar segment 2.1× as long as wide. Tyloids on flagellar segments 5-12/13, linear, indistinctly differentiated. Temple moderately and roundly narrowed behind eye. OED 1.0-1.1× and OOD 1.5-1.6× ocellar diameter. Frons with dense punctures and transverse rugosities; face densely rugose-punctate. Clypeus smooth and shining, with sparse punctures. MI 0.2. Seen from lateral, gena distinctly narrowed ventrally and rather densely punctate ventrally. Hypostomal carina slightly elevated.

Mesoscutum, mesopleuron and metapleuron densely punctate, smooth between punctures; speculum partly smooth. Epicnemial carina distinctly elevated and bilobed behind fore coxa. Scutellum moderately elevated, slightly wider than long, lateral carina in basal 0.3-0.5. Area superomedia heart-shaped, slightly longer than wide; costula reaching at 7/10 its length. Fore metatarsus with distinct apical tooth. Hind femur 3.4-3.7× as long as wide. External surface of hind tibia with several denticular spines.

Postpetiole densely punctate, without latero-median carina; median field not differentiated. Gastrocoelus impressed, but almost smooth. Thyridium slightly oblique, 0.7× as wide as interval between thyridia. 2 nd to 5 th tergites with dense punctures.

Color: black. Setae of mesoscutum brownish. Flagellum black, distal flagellar segments reddish ventrally. Palps partly, clypeus laterally, wide facial orbit and narrow frontal orbit up to vertex (fig. 72), sometimes spot of collar and hind edge of pronotum, spot of subtegular ridge, and posterolateral spots on scutellum ivory. Petiole black. Postpetiole ± and 2 nd to 5 th tergites entirely red; 6 th and 7 th tergites black. Coxae and trochanters black; legs otherwise red; fore and mid femora infuscate ventrally; fore and mid tibiae yellow frontally; hind femur red, baso-ventrally and apically ± infuscate; hind tibia red, black in apical 0.3; hind tarsus black. Pterostigma reddish-brown.

T a x o n o m i c a l r e m a r k s: The form of the gastrocoelus of this species resembles some members of the genus Barichneumon THOMSON but the long 1 st flagellar segment is typical for Virgichneumon (see RIEDEL 2014). It should be noted that the species has been usually misidentified in the past: Barichneumon perversus sensu RASNITSYN & SIYTAN (1981) belongs to a different Barichneumon species.

S t u d i e d m a t e r i a l: from Germany and Italy.