Mesochorus dessauensis 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 : 4-5

5. Mesochorus dessauensis SCHWENKE, 1999

( Figs 5a–d )

Holotype: "() Dessau 4 km SW 19.9.85 K.H. Zoerner; 366/85 Taubeufer" [, no. 366/85, Germany: Saxony- Anhalt , 4 km SW of the district Dessau of town Dessau-Rosslau, shore of the river Taube, 19.9.1985, leg. K.H. Zoerner] ( SDEI).

Description: Missing: Left flagellomeres from 23 th on, right flagellomeres from 15 th on. Body length 4.0 mm. 1 st flagellomere 6.1x longer than wide and 0.64x as long as eye 2 nd flagellomeres 4.1x longer than wide; central flagellomeres ca. 2x longer than wide. Temple short, strongly narrowed behind eyes, 0.3x as long as the eye width. Ocelli very large, OOD 0.5. Face with superficial punctures, 1.05x wider than the length of clypeus+face and 0.8x as wide as the eye length, sides convergent ventrally. Mandible with two equal teeth. Malar space and ventral 0.3 of facial orbit striate. MI 0.2. Genal carina reaching the hypostomal carina far from mandibular base. Mesoscutum with fine superficial punctures; mesopleuron smoothened dorsally, with few fine hair-punctures ventrally; metapleuron smooth. Area basalis trapezoid, wider than long; area superomedia 1.7x longer than wide and 0.95x as long as the length of area petiolaris, costula in frontal 4/10 of length of area superomedia; area petiolaris 1.05x longer than wide. Hind femur 4.5x longer than wide; hind metatarsus 0.45x as long as the hind tibia; hind claws with two long visible tooth. Areolet shortly sessile, oblique, 2 nd recurrent vein proximal to its middle; nervulus interstitial; pterostigma 3.1x longer than wide, radial vein in its distal 0.62. 1 st tergite 3.1x longer than wide; postpetiolus 1.6x longer than wide, smooth; 2 nd tergite 0.95 as long as wide; thyridium roundish. Ovipositor sheath pilose, 8.4x longer than wide and 1.2x longer than the hind metatarsus, slightly bent upwards and moderately narrowed in the apical 3/10 of tibial length.

Colour: Black. Flagellum brownish-yellow. Face reddish; clypeus, inner orbit, mandible except teeth, malar space and gena cream-yellow; outer orbit yellow. Mesosoma brownish; hind edge of pronotum, tegula and wing base cream-yellow; mesoscutum with 4 yellow stripes which are confluent frontally; scutellum yellow, with brown central stripe. 1 st tergite black, reddish basally; 2 nd tergite black, with arched yellow band in the apical 2.5/10 of tibial length; 3 rd tergite yellowish-red in the basal 0.6, brownish apically; following tergites brown, with grey apical bands. Legs reddish-yellow; hind coxa with brownish spot dorsally; hind tibia cream-yellowish, brownish in apical 2/10 of tibial length (1.5x of tibial width). Pterostigma brown, proximal and distal corners hyaline.

Remark: Due to the brownish dorsal spots on hind coxae, this species runs to no. 14 ( Mesochorus callis SCHWENKE ) in the key for the orbitalis -group ( SCHWENKE, 1999: 62–63). It differs from M. callis SCHWENKE by its very large ocelli and reddish face.

Figures

Fig. 5a-d: Holotype of Mesochorus dessauensis SCHWENKE: a. face; b. mesosoma; c. metasoma; d. ovipositor sheath.