Mesochorus (Mesochorus) rufator, Riedel, 2023

Riedel, Matthias, 2023, Contribution to the taxonomy of the Southeast Asian Mesochorinae (Hymenoptera, Ichneumonidae), Zootaxa 5245 (1), pp. 1-72 : 29-30

Mesochorus (Mesochorus) rufator nov. sp.

( Fig. 5D , 11G , 19A , 23J )

Holotype. (♀) NW Vietnam: Tonkin, Hoang Lien N. R., 15 km W Sa Pa , c. 1900 m, 15–21.x.1999, Malaise traps, C. v. Achterberg, RMNH´99 (Leiden).

Etymology. The species name refers to the reddish body color.

Description. ♀: Body length 8.5 mm. Length of fore wing 7.7 mm.

Head. Flagellum with 47 flagellomeres; 1 st flagellomere 6.1 × longer than wide and 1.7 × longer than 2 nd flagellomere, 0.7 × as long as eye; 2 nd flagellomere 3.8 × longer than wide; preapical flagellomere 3.0 × longer than wide. Temple moderately and roundly narrowed behind eye, dorsally c 0.5 × as long as eye. OED 0.9 × and OOD 0.4 × ocellar diameter. Frons with sparse punctures and fine aciculation laterally. Face ( Fig. 11G ) coarsely punctate, with central longitudinal ridge in dorsal half, width 1.0 × combined length of face and clypeus and 0.9 × eye length; inner eye margins slightly divergent. Subantennal transverse carina dipped medially. Malar space and ventral 0.2 of facial orbit weakly striate. Malar space 0.3 × as long as width of mandibular base. Mandible with two equal teeth. Genal carina reaching hypostomal carina away from mandibular base, both carinae low.

Mesosoma . 1.6 × longer than high. Mesoscutum coarsely and densely punctate apico-centrally, lateral lobe with rather dense but superficial punctures. Scuto-scutellar groove, densely and finely punctate. Scutellum moderately convex, densely punctate, without lateral carina, not pointed apically. Mesopleuron and metapleuron with dense punctures, speculum smooth. Dorsal end of epicnemial carina separated from frontal margin of mesopleuron. Submetapleural carina lamelliform frontally. Propodeum (19A) completely carinate, except confluent area basalis and area superomedia. Area basalis rectangular, about as long as wide. Area superomedia 2.2 × longer than wide and 1.4 × longer than area petiolaris; anterior transverse carina (costula) reaching 3/10 of its length. Area petiolaris about as long as wide. Tarsi slender; distal fore tarsomere 3.3 × longer than wide. Hind femur 5.0 × longer than wide; hind metatarsus 0.5 × as long as hind tibia and 2.4 × longer than 2 nd hind tarsomere. Claws large, hind claw with 6 dense and short basal teeth. Areolet pointed frontally; vein 2m-cu slightly proximad its middle. Vein 1cu-a interstitial. Postnervulus intercepted basad its middle. Pterostigma 3.3 × longer than wide. Hind wing with 5 distal hamuli. Nervellus of hind wing slightly reclivous.

Metasoma. 1 st tergite slender, 3.1 × longer than wide. Postpetiolus with long central rim and some fine rugae. 2 nd tergite 1.2 × longer than wide. Thyridium transverse-oval. Ovipositor sheath ( Fig. 23J ) densely pilose, 9.2 × longer than wide, 0.4 × as long as hind tibia and 0.9 × as long as hind metatarsus, distinctly narrowed in apical 0.4.

Color. Body reddish. Palps, clypeus, mandible except teeth, malar space, ventral gena, facial orbit and ventral half of frontal orbit cream-yellow. Hind edge of pronotum and tegula cream-yellow. Propleuron, ventral pronotum, and mesosternum yellow. 2 nd tergite with narrow yellow hind margin. Fore and mid coxae and trochanters creamyellow, legs otherwise reddish-yellow. Pterostigma ochreous.

♁ unknown.

Taxonomical remark. This species belongs to the fulvus group sensu Schwenke (1999), e.g. mesosoma and metasoma reddish, without dark spots. It resembles Mesochorus tattakensis Uchida, 1933 . M. tattakensis differs from this new species by its larger size (10.0 mm), two weak paramedian yellow lines on mesoscutum, a yellow pterostigma and separated area basalis and area superomedia. It is possible that these differences reflect only intraspecific variations of one species.

Figures

FIGURE 5. Oriental Mesochorinae, habitus from lateral. A−Mesochorus paratenebris n. sp. HT, B−M. pictiloides n. sp. HT, C−M. pterostigmator n. sp., D−M. rufator n. sp. HT, E−M. sabahensis n. sp. HT, F−M. sapaensis n. sp. HT.

FIGURE 11. Oriental Mesochorinae, face from frontal. A− Mesochorus nigrofemur n. sp. HT (♀), B−M. nigrofemur n. sp. PT (♁), C−M. nigromaculatus n. sp. HT, D−M. paratenebris n. sp. HT, E−M. pictiloides n. sp. HT, F−M. pterostigmator n. sp., G−M. rufator n. sp. HT, H−M. sabahensis n. sp. HT.

FIGURE 19. Oriental Mesochorinae, propodeum from dorsal. A−Mesochorus rufator n. sp. HT, B−M. sabahensis n. sp. HT, C−M. sapaensis n. sp. HT, D−M. semifuscus n. sp. PT, E−M. semipunctatus n. sp. HT, F−M. siamensis n. sp. HT, G−M. stigmaticolor n. sp. HT, H−M. striatofacies n. sp. PT (♁), I−M. sumaterae n. sp. HT.

FIGURE 23. Oriental Mesochorinae, ovipositor sheath from lateral.A−Mesochorus longivalvator n. sp. HT, B−M. malaysiacus n. sp. HT, C−M. malucutus n. sp. HT, D−M. nigripleuris n. sp., E−M. nigrofemur n. sp. HT (♀), F−M. nigromaculatus n. sp. HT, G−M. paratenebris n. sp. HT, H−M. pictiloides n. sp. HT, I−M. pterostigmator n. sp., J−M. rufator n. sp. HT, K−M. sabahensis n. sp. HT, L−M. sapaensis n. sp. HT, M−M. semifuscus n. sp. HT, N−M. semipunctatus n. sp. HT.