Mesochorus obscurus 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 : 10-11

17. Mesochorus obscurus SCHWENKE, 1999

( Figs 16a–d )

Holotype: "() Dessau 1,3 SO 15.9.1993 347/93 H. Zoerner " [, no. 347/93, Germany: Saxony-Anhalt, 1.3 km SE of the district Dessau of town Dessau-Rosslau, 15.9.1993, leg. K.H. Zoerner] ( SDEI).

Description: Missing: Right flagellum. Body length 3.1 mm. Flagellum with 26 flagellomeres; 1 st flagellomere 6.7x longer than wide and 0.62x as long as the eye; 2 nd flagellomere 4.0x longer than wide; preapical flagellomeres ca. 1.5x longer than wide. Temple strongly narrowed behind eye, ca. 0.5x as long as the eye width. OOD 1.0. Face narrow, coarsely punctate, sides convergent ventrally, 0.95x as wide as the length of clypeus+face and 0.85x as the eye length. Clypeus with coarse punctures. MI 0.2. Malar space striate. Mandible with two equal teeth. Genal carina reaching the hypostomal carina far from mandibular base. Mesoscutum with fine dense punctures apico-medially, with scattered punctures laterally; mesopleuron with fine punctures dorsally, almost smooth ventrally; metapleuron with very fine scattered punctures. Area basalis trapezoid, slightly longer than wide; area superomedia 1.9x longer than wide and 1.6x longer than the area petiolaris, costula in frontal 4/10 of length of area superomedia; area petiolaris 0.86x as long as wide. Hind femur 4.1x longer than wide; hind metatarsus 0.47x as long as the hind tibia. Claws without visible teeth. Areolet shortly sessile, 2 nd recurrent vein in its middle; nervulus slightly postfurcal (by 0.5x its width); pterostigma 3.1x longer than wide, radial vein in its distal 0.68. 1 st tergite 2.6x longer than wide; postpetiolus ca. 1.3x longer than wide, with central rim and some rugae; 2 nd tergite about as long as wide; thyridium transverse-oval. Stylet stabshaped, clubbed apically, 1.3x longer than the 2 nd hind tarsomere.

Colour: Black. Flagellum brownish yellow, basal two flagellomeres yellowish. Face reddish; wide facial orbit, wide spot opposite to antennal base, base of mandible, and malar space yellow. Orbits otherwise yellowish-red. Mesosoma black; pronotum reddish-brown; hind edge of pronotum, tegula and wing base yellow. 1 st tergite black; 2 nd tergite with yellow-red band in the apical 2.5/10 of tibial length; 3 rd tergite yellow-red basally and centrally, sides and hind margin brown; following tergites blackish, with dark-grey hind margins. Legs reddish-yellow; hind coxa and hind femur with some reddish-brown suffusion dorsally; hind tibia yellow, basally and in the apical 1/10 of tibial length (1x its width) brownish; hind tarsus except basal half of metatarsus brownish. Pterostigma pale brownish.

Remark: The inclusion of this species into the dispar - group is questionable because the ocelli are large, the areolet is only shortly sessile and the nervulus is slightly postfurcal. If one accepts this position, the species are correctly placed in the key for the dispar -group ( SCHWENKE, 1999: 48–51). Using the other key for males ( SCHWENKE, 1999: 115–118), this taxon would run to no. 58 ( Mesochorus caliginosus SCHWENKE ) but differs by its smaller size and smoothened mesopleuron.

Valid name: Mesochorus anhaltinus SCHWENKE, 2002 , new name for Mesochorus obscurus SCHWENKE, 1999 , preoccupied by DASCH, 1974.

Figures

Fig. 16a-d: Holotype of Mesochorus obscurus SCHWENKE: a. face; b. mesosoma; c. metasoma; d. ovipositor sheath.