Mesochorus (Mesochorus) brevipunctatus, Riedel, 2023

Riedel, Matthias, 2023, Contribution to the taxonomy of the Southeast Asian Mesochorinae (Hymenoptera, Ichneumonidae), Zootaxa 5245 (1), pp. 1-72 : 8-9

Mesochorus (Mesochorus) brevipunctatus nov. sp.

( Figs 8E , 17D , 22C )

Holotype. (♀) Indonesia: Sula Isl. , Mangole , near Buya, Schacht-trap 17, c 500 m, 2–22.iii.1995, C. v. Achterberg & Y. Yasir, RMNH (Leiden).

Etymology. The species name refers to the reduced punctuation of the facial orbit.

Description. ♀: Body length 4.4 mm. Fore wing 3.7 mm.

Head. Flagellum with> 9 flagellomeres (tips broken off); 1 st flagellomere 7.0 × longer than wide and 1.6 × longer than 2 nd flagellomere, 0.7 × as long as eye; 2 nd flagellomere 4.3 × longer than wide. Temple strongly and roundly narrowed behind eye, dorsally c 0.3 × as long as eye. OED 1.3 × and OOD 0.4 × ocellar diameter. Occipital carina widely absent medially. Frons with microsculpture and few sparse punctures. Face ( Fig. 8E ) with rather dense but partly sparse punctures paramedially, with short dorsal longitudinal ridge and slight lateral impressions below subantennal carina, width 1.0 × combined length of face and clypeus and 1.1 × eye length; inner eye margins parallel. Subantennal transverse carina dipped medially. Ventral half of facial orbit widely, malar space and mandible striate. Malar space 1.0 × as long as width of mandibular base. Mandible with two rather small equal teeth. Genal carina reaching hypostomal carina away from mandibular base, both carinae low.

Mesosoma . 1.6 × longer than high. Mesoscutum densely punctate postero-medially, lateral lobe with superficial punctures. Scuto-scutellar groove finely punctate. Scutellum moderately convex, without lateral carina, not pointed apically. Mesopleuron with dense punctures fronto-dorsally and sparse punctures ventrally. Dorsal end of epicnemial carina separated from frontal margin of mesopleuron. Metapleuron with fine sparse setiferous punctures. Submetapleural carina slightly lamelliform. Propodeum ( Fig. 17D ) completely carinate. Area basalis triangular, about as long as wide. Area superomedia 1.4 × longer than wide and 0.8 × as long as area petiolaris; anterior transverse carina (costula) reaching at 4/10 of its length. Area petiolaris large, 1.1 × longer than wide. Hind femur 4.4 × longer than wide; hind metatarsus 0.6 × as long as hind tibia and 2.9 × longer than 2 nd hind tarsomere; hind claw covered with dirt; teeth not visible. Areolet pointed frontally; vein 2m-cu distinctly proximad its middle. Vein 1cu-a interstitial. Postnervulus intercepted basad its middle. Pterostigma 3.3 × longer than wide. Hind wing with 4 distal hamuli.

Metasoma. 1 st tergite 2.4 × longer than wide. Postpetiolus smooth. 2 nd tergite about as long as wide. Thyridium comma-shaped. Ovipositor sheath ( Fig. 22C ) sparsely pilose, stick-shaped, 10.3 × longer than wide, 0.7 × as long as hind tibia and 1.1 × longer than hind metatarsus.

Color. Flagellum brownish; scape and pedicel reddish-yellow; two basal flagellomeres reddish. Head reddishyellow. Palps, malar space and wide facial orbit cream-yellow. Mesosoma reddish-yellow; propleuron, pronotum, tegula, mesopleuron and metapleuron cream-yellow. Propodeum pale yellow; area basalis, area externa and area dentipara reddish-yellow. 1 st tergite reddish-yellow, basally pale yellow, with brown stripes laterally. 2 nd tergite yellow, with V-shaped brown spot in basal half. Following tergites yellow. Ovipositor sheath pale brownish. Fore and mid coxae and all trochanters cream-yellow. Legs otherwise yellowish; hind tibia narrowly reddish-brown basally and in apical 0.2. Hind tarsus ochreous. Pterostigma pale brown.

♁ unknown.

Taxonomical remark. The metasoma of this new species has the basal tergites with some brown spots and apical tergites entirely yellow (declinans group sensu Schwenke, 1999). It is characterized by the reduced punctuation of the face, medially absent occipital carina, and the entirely reddish-yellow mesosoma with cream-yellow sides.

Figures

FIGURE 8. Oriental Mesochorinae, face from frontal. A−Orientochorus tonkinensis n. sp. holotype (HT), B−Astiphromma bicoloratus n. sp. HT, C−Mesochorus achterbergi n. sp. HT, D−M. annamensis n. sp. HT, E−M. brevipunctatus n. sp. HT, F−M. cariniscuta n. sp. HT, G−M. controversus n. sp. HT, H−M. diversidens n. sp. HT (♀).

FIGURE 17. Oriental Mesochorinae, propodeum from dorsal. A−Orientochorus tonkinensis n. sp. HT, B−Astiphromma bicoloratus n. sp. HT, C−Mesochorus annamensis n. sp. HT, D−M. brevipunctatus n. sp. HT, E−M. cariniscuta n. sp. HT, F−M. diversidens n. sp. HT (♀), G−M. fuscomaculatus n. sp. HT, H−M. halmaherae n. sp. HT, I−M. harlequinus n.sp. HT.

FIGURE 22. Oriental Mesochorinae, ovipositor sheath from lateral. A−Orientochorus tonkinensis n. sp. holotype (HT), B−Mesochorus annamensis n. sp. HT, C−M. brevipunctatus n. sp. HT, D−M. cariniscuta n. sp. HT, E−M. controversus n. sp. HT, F−M. diversidens n. sp. HT, G−M. flavator n. sp. HT, H−M. flavopronotalis n. sp. HT, I−M. fuscomaculatus n. sp. HT, J−M. halmaherae n. sp. HT, K−M. harlequinus n.sp. HT, L−M. kinabaluensis n. sp. HT, M−M. lamdongensis n. sp. HT, N−M. longimurus n. sp. HT.