Mesochorus frondosus 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 : 6-7

9. Mesochorus frondosus SCHWENKE, 1999

( Figs 9a–d )

Holotype: "() Dessau 7.5 km S 25.7 .88 K.H. Zoerner; 154/88 Waldwege" [, no. 154/88, Germany: Saxony-Anhalt, 7.5 km S of the district Dessau of town Dessau-Rosslau , on forest trails, 25.7.1988, leg. K.H. Zoerner] ( SDEI).

Description: Missing: Left flagellomeres from the 6 th on. Body length 2.5 mm. Flagellum with 23 flagellomeres; 1 st flagellomere 7.5x longer than wide and 0.59x as long as the eye; 2 nd flagellomere 5.0x longer than wide; preapical flagellomeres ca. 2.0x longer than wide. Temple long, moderately and roundly narrowed behind eye, 0.8x as long as the eye width. OOD 1.8. Face smoothened centrally, 1.05x as wide as the length of clypeus+face and 0.88x as wide as the eye length, with parallel sides. Clypeus with scattered coarse punctures, apical margin straight. MI 0.8. Mandible with two equal teeth. Facial orbit completely and widely and malar space widely striate. Genal carina reaching the hypostomal carina far from mandibular base. Mesosoma stout, ca. 1.5x longer than high. Mesoscutum almost smooth, with few fine hair-punctures; side of pronotum, mesopleuron and metapleuron smooth. Area basalis almost rectangular, slightly longer than wide; area superomedia ca. 1.7x longer than wide and 0.85x as long as the area petiolaris, costula in frontal 4/10 of length of area superomedia; area petiolaris 1.1x longer than wide. Hind femur 4.1x longer than wide; hind metatarsus 0.45x as long as the hind tibia; hind claws with few short basal teeth. Areolet shortly stalked, oblique, 2 nd recurrent vein slightly proximal to its middle; nervulus interstitial; pterostigma 2.9x longer than wide, radial vein in its distal 0.5; distal part of radial vein long, sinusoid. 1 st tergite 3.2x longer than wide, postpetiolus 1.3x longer than wide, smooth; 2 nd tergite 0.85x as long as wide; thyridium comma-shaped. Ovipositor sheath with scattered hairs, 7.1x longer than wide and 0.95x as long as the hind metatarsus; slightly narrowed and bent upwards apically.

Colour: Black. Face brown, with blackish central spot; facial orbit, mandible except teeth, malar space and gena yellow. Flagellum brownish. Mesosoma blackish; hind edge of pronotum, tegula and wing base yellow. 1 st sternite yellow-red; 1 st tergite black, dark reddish basally, narrowly yellow apically; 2 nd tergite black, yellow basally and in the apical 2/10 of tibial length; 3 rd tergite brown, yellow in the basal 0.3; following tergites blackish. Legs reddish-yellow; hind tibia yellow, pale brownish in apical 1.5/10 to 2/10 of tibial length (1–1.5x of tibial width). Pterostigma brownish.

Remark: This species is correctly placed in the key of the curvulus- group ( SCHWENKE, 1999: 35–37), but seen from dorsal, the temples are slightly shorter than the eye width.

Figures

Fig. 9a-d: Holotype of Mesochorus frondosus SCHWENKE:a. face; b. mesosoma; c. metasoma; d. ovipositor sheath.