Mesochorus (Stictopisthus) halmaherae, Riedel, 2023

Riedel, Matthias, 2023, Contribution to the taxonomy of the Southeast Asian Mesochorinae (Hymenoptera, Ichneumonidae), Zootaxa 5245 (1), pp. 1-72 : 15-16

Mesochorus (Stictopisthus) halmaherae nov. sp.

( Figs 2F , 9F , 17H , 22J )

Holotype. (♀) Indonesia: S Halmahera, between Payahe & Gita Woda, Schacht-trap 6, c 30 m, 17.ii. –17.iii.1995, C. v. Achterberg, R. de Vries & Y. Yasir, RMNH´95 (Leiden).

Description. ♀: Body length 3.3 mm. Fore wing 2.8 mm.

Head. Flagellum with 31 flagellomeres; 1 st flagellomere 5.6 × longer than wide and 1.5 × longer than 2 nd flagellomere, 0.6 × as long as eye; 2 nd flagellomere 3.5 × longer than wide; preapical flagellomere 2.5 × longer than wide. Occipital carina complete medially. Temple moderately and roundly narrowed behind eye, dorsally c 0.5 × as long as eye. OED 2.0 × and OOD 0.7 × ocellar diameter. Frons almost smooth, with fine longitudinal ridge below anterior ocellus. Face ( Fig. 9F ) with sparse to rather dense punctures, width 1.0 × combined length of face and clypeus and 1.0 × eye length; inner eye margins slightly convergent ventrally. Subantennal transverse carina not dipped medially. Malar space and facial orbit not striate. Malar space 0.7 × as long as width of mandibular base. Mandible rather slender, with two equal teeth. Genal carina reaching hypostomal carina away from mandibular base, both carinae low.

Mesosoma . 1.6 × longer than high. Side of pronotum largely smooth. Notaulus indistinct. Mesoscutum with rather dense punctures apico-medially, punctures of lateral lobe very superficial. Mesopleuron with dense coarse punctures, speculum smooth. Dorsal end of epicnemial carina reaching frontal margin of mesopleuron. Metapleuron densely punctate; submetapleural carina slightly lamelliform; juxtacoxal carina absent. Scuto-scutellar groove 2.8 × wider than long, with c 6 longitudinal ridges. Scutellum slightly rounded in profile, with fine very sparse punctures. Propodeum ( Fig. 17H ) completely carinate. Area basalis trapezoid, confluent with area superomedia. Area superomedia 2.0 × longer than wide, with transverse rugae; anterior transverse carina (costula) reaching slightly distad its middle. Area petiolaris about as long as wide. Hind femur 3.7 × longer than wide; hind metatarsus 0.6 × as long as hind tibia and 3.0 × longer than 2 nd hind tarsomere; hind claw with two long basal teeth. Areolet shortly sessile frontally; vein 2m-cu in its middle. Vein 1cu-a postfurcal by 1.0 × its length. Postnervulus intercepted distad its middle. Pterostigma 3.0 × longer than wide. Distal part of RA (metacarp) long, about as long as width of pterostigma. Hind wing with 4 distal hamuli. Nervellus of hind wing vertical.

Metasoma. 1 st tergite 2.5 × longer than wide. Postpetiolus with longitudinal rugae. 2 nd tergite 1.2 × wider than long. Thyridium comma-shaped. Ovipositor sheath ( Fig. 22J ) with sparse setae, 7.4 × longer than wide, 0.5 × as long as hind tibia and 0.9 × as long as hind metatarsus, moderately bent upwards apically.

Color. Body mainly reddish-yellow. Flagellum brownish, basal flagellomeres ochreous; scape and pedicel reddish-yellow. Palps, mandible except teeth, malar space and ventral third of facial orbit cream-yellow. 1 st tergite brownish, basally yellow, partly reddish at apex. 2 nd tergite yellow, with V-shaped brown spot in basal 0.4. Following tergites yellow; 3 rd tergite with brownish spot in apical 0.3. Ovipositor sheath brown. Fore and mid coxae and trochanters cream-yellow; legs otherwise yellowish; hind tibia narrowly infuscate basally and apically; hind tarsus ochreous. Pterostigma brownish-hyaline.

♁ unknown.

Taxonomical remark. The species belongs to the subgenus Stictopisthus and is characterized by partly reduced punctuation of face, coarse punctures of mesopleuron and metapleuron, brown pterostigma, and confluent area basalis and area superomedia.

Figures

FIGURE 2. Oriental Mesochorinae, habitus from lateral. A−Mesochorus controversus n. sp. HT, B−M. diversidens n. sp. HT, C−M. flavator n. sp., D−M. flavopronotalis n. sp. HT, E−M. fuscomaculatus n. sp. HT, F−M. halmaherae 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 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.