Mesochorus (Mesochorus) harlequinus, Riedel, 2023

Riedel, Matthias, 2023, Contribution to the taxonomy of the Southeast Asian Mesochorinae (Hymenoptera, Ichneumonidae), Zootaxa 5245 (1), pp. 1-72 : 16-17

Mesochorus (Mesochorus) harlequinus nov. sp.

( Figs 3A , 9G , 16D , 17I , 21B , 22K )

Holotype. (♀) N Vietnam: Hoa Binh, Hang Kia Pà Cò N. R., 1027 m, N 20°44´35´´ E 104°56´23´´, 2.iii. –15.iv.2011, Exp. Mal. Tr. 1, C. v. Achterberg, RMNH´11 (Leiden).

Etymology. The species name refers to the very diverse color pattern of the body that reminds of the clothes of medieval harlequins.

Description. ♀: Body length 4.5 mm. Length of fore wing 4.1 mm.

Head. Flagellum with 33 flagellomeres; 1 st flagellomere 6.1 × longer than wide and 1.6 × longer than 2 nd flagellomere, 0.7 × as long as eye; 2 nd flagellomere 4.2 × longer than wide; preapical flagellomere 2.2 × longer than wide. Temple moderately and roundly narrowed behind eye, dorsally c 0.6 × as long as eye. OED 1.4 × and OOD 0.6 × ocellar diameter. Occipital carina complete medially. Frons smooth, with rectangular central elevation below anterior ocellus and some coarse punctures opposite to lateral ocellus. Face ( Fig. 9G ) coarsely punctate, with central elevation but without distinct longitudinal ridge, width 1.1 × combined length of face and clypeus and 1.1 × eye length; inner eye margins parallel. Subantennal transverse carina dipped medially. Malar space and ventral half of facial orbit striate. Malar space 0.9 × 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 densely punctate, partly rugose-punctate apico-centrally. Scuto-scutellar groove smooth. Scutellum slightly convex, finely punctate, without lateral carina, not pointed apically. Mesopleuron ( Fig. 16D ) densely punctate. Dorsal end of epicnemial carina separated from frontal margin of mesopleuron. Metapleuron with fine dense punctures. Submetapleural carina slightly low. Propodeum ( Fig. 17I ) completely carinate.Area basalis triangular, slightly longer than wide. Area superomedia 1.3 × longer than wide and 0.9 × as long as area petiolaris; anterior transverse carina (costula) reaching at 4/10 of its length. Area petiolaris 1.3 × longer than wide. Hind femur 4.8 × longer than wide; hind metatarsus 0.6 × as long as hind tibia and 2.6 × longer than 2 nd hind tarsomere; hind claw ( Fig. 21B ) with c 3 basal teeth, mid tooth very long, almost longer than its claw. Areolet shortly sessile frontally; vein 2m-cu slightly proximad its middle. Vein 1cu-a slightly postfurcal by 0.3 × its length. Postnervulus intercepted basad its middle. Pterostigma 3.1 × longer than wide. Hind wing with 4 distal hamuli. Nervellus of hind wing slightly reclivous.

Metasoma. 1 st tergite 3.0 × longer than wide. Postpetiolus with weak central impression and few fine rugae apically. 2 nd tergite 1.1 × wider than long. Thyridium roundish. Ovipositor sheath ( Fig. 22K ) stick-shaped, densely pilose, 10.8 × longer than wide, 0.6 × as long as hind tibia and 1.1 × as long as hind metatarsus

Color. Scape, pedicel and flagellum basally reddish-brown, brownish distally. Clypeus and face cream-yellow, with reddish-brown median stripe. Palps, mandible except teeth, malar space and gena cream-yellow. Vertical and frontal orbits yellowish. Frons medially, and occiput dorsally brown. Propleuron brownish. Pronotum creamyellow, with brown spot laterally. Mesoscutum yellowish, with three blackish stripes. Scuto-scutellar groove black. Scutellum yellow, with brown basal spot. Mesopleuron and metapleuron black. Propodeum yellow, with lateral brownish stripes. 1 st tergite mainly yellow, postpetiolus with brown lateral stripes. 2 nd tergite black, with large triangular pale-yellow spot in apical 3/4. 3 rd tergite pale yellow, brown laterally and apically. 4 th to 7 th tergites pale yellow, with brown transverse apical stripes. Ovipositor sheath brown. Fore and mid coxae and all trochanters cream-yellow; fore and mid legs otherwise yellow. Hind coxa yellow, with brown lateral stripe. Hind femur reddishbrown; hind tibia yellow, black in basal 0.2 and apical 0.3; hind tarsus except mainly yellow metatarsus brown. Pterostigma brown.

♁ unknown.

Taxonomical remark. With its sessile areolet, postfurcal vein 1cu-a, stick-shaped ovipositor and short area superomedia, this species belongs to the dispar group sensu Schwenke (1999). Besides its typical color pattern, it is characterized by its densely punctate mesopleuron and one very long tooth of hind claw.

Figures

FIGURE 3. Oriental Mesochorinae, habitus from lateral.A−Mesochorus harlequinus n. sp. HT, B−M. kinabaluensis n. sp. HT, C−M. lamdongensis n. sp., D−M. longimurus n. sp. HT, E−M. longistylus n. sp. HT, F−M. longivalvator n. sp. HT.

FIGURE 9. Oriental Mesochorinae, face from frontal. A− Mesochorus diversidens n. sp. paratype (PT) (♁), B−M. flavator n. sp. HT, C−M. flavopronotalis n. sp. HT (♀), D−M. flavopronotalis n. sp. PT (♁), E−M. fuscomaculatus n. sp. HT, F−M. halmaherae n. sp. HT, G−M. harlequinus n.sp. HT, H−M. kinabaluensis n. sp. HT.

FIGURE 16. Oriental Mesochorinae, mesopleuron from lateral. A−Orientochorus tonkinensis n. sp. HT, B−Mesochorus sulaensis n. sp. HT with juxtacoxal carina present, C−M. flavopronotalis n. sp. HT (♀), D−M. harlequinus n.sp. HT, E−M. malucutus n. sp. HT, F –M. pterostigmator n. sp. HT, G−M. tonkinesis n. sp. HT, H−M. vietnamensis 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 21. Oriental Mesochorinae, hind claw. A−Mesochorus stigmaticolor n. sp. HT, B−M. harlequinus n. sp. PT

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.