Mesochorus opacus SCHWENKE, 1999

Riedel, Matthias, 2018, The types of Mesochorus GRAVENHORST (Hymenoptera, Ichneumonidae, Mesochorinae) described by W. SCHWENKE and deposited in the Senckenberg Deutsches Entomologisches Institut, Beiträge Zur Entomologie = Contributions to Entomology 68 (1), pp. 1-29 : 11

18. Mesochorus opacus SCHWENKE, 1999

( Figs 17a–d )

Holotype: "() Oppach 1,3 km O 8.1993 275/93 H. Zoerner " [, no. 275/93, Germany: Saxony, 1.3 km E of Oppach, 8.1993, leg. K.H. Zoerner] ( SDEI).

Description: Missing: Left and right flagellomeres from 26 th on, right 4 th and 5 th fore tarsomeres. Body length 4.7 mm. 1 st flagellomere 6.1x longer than wide and 0.69x as long as the eye; 2 nd flagellomere 4.0x longer than wide. Temple very short and strongly narrowed behind eye, ca. 0.3x as long as the eye width. Ocelli very large, OOD 0.5. Face with coarse and dense punctures, with distinct central ridge, slightly convergent ventrally, facial orbit superficially punctate and shining, about as wide as the length of clypeus+face and 0.75x as wide as the eye length. Clypeus almost smooth. MI 0.2. Mandible with two equal teeth. Genal carina reaching the hypostomal carina far from mandibular base. Mesoscutum with fine scattered punctures; mesopleuron with fine and dense punctures dorsally and very scattered small hairpunctures ventrally; metapleuron with fine scattered punctures. Area basalis rectangular, 1.5x longer than wide; area superomedia 2.4x longer than wide and 1.4x longer than the area petiolaris, costula in frontal 3/10 of length of area superomedia; area petiolaris 0.8x as long as wide. Hind femur 4.2x longer than wide; hind metatarsus 0.49x as long as the hind tibia; hind claws with four basal teeth. Areolet pointed sessile, 2 nd recurrent vein slightly proximal to its middle; nervulus interstitial; pterostigma 3.3x longer than wide, radial vein in its distal 0.67. 1 st tergite 2.3x longer than wide; postpetiolus 1.25x longer than wide, smooth; 2 nd tergite 1.05x longer than wide, thyridium transversal-oval. Ovipositor sheath pilose, sabre-shaped, ventrally rounded, 5.3x longer than wide and 0.85x as long as the hind metatarsus, narrowed in the apical 3/10 of tibial length.

Colour: Black. Flagellum blackish, basal flagellomeres reddish-brown. Head with face blackish; mandible except teeth and malar space yellowish, clypeus reddish. Mesosoma blackish. Hind edge of pronotum, tegula and wing base cream-yellow, fronto-dorsal edge of the mesopleuron reddish-brown. Legs reddish; hind tibia yellow, brownish basally and in the apical 2/10 of tibial length. Metasoma black; 2 nd tergite yellowish in the apical 1/10 of tibial length. Pterostigma brownish.

Remark: The species is correctly placed in the key of the angustatus -group ( SCHWENKE, 1999: 72–73). SCHWENKE separated this taxon from Mesochorus rubeculus HARTIG mainly by its dark facial orbits. The colour of facial orbits is variable in M. rubeculus , and both species are synonymized here.

Valid name: Mesochorus rubeculus HARTIG, 1838

syn. nov. Mesochorus opacus SCHWENKE, 1999 .

Figures

Fig. 17a-d: Holotype of Mesochorus opacus SCHWENKE: a. face; b. mesosoma; c. metasoma; d. ovipositor sheath.