Gnathochorisis sapaensis Varga, 2025

Varga, Oleksandr, 2025, First records of the genera Gnathochorisis Förster, 1869 and Symplecis Förster, 1869 (Hymenoptera, Ichneumonidae, Orthocentrinae) from Vietnam, Zootaxa 5647 (6), pp. 571-583 : 572

Gnathochorisis sapaensis Varga , sp. nov.

urn:lsid:zoobank.org:act:CD013F02-6E7B-4E89-A47E-5F307DD878D3

( Fig. 1 )

Material examined. Holotype: ♀, VIETNAM: Tonkin , Hoang Lien N. R., 15 km W Sa Pa, ca. 1900 m, Malaise traps, 15–21.x.1999, leg. C. v. Achterberg, RMHN’99, RMNH.INS.1722319 ( RMNH) . Paratype: 1 ♂, the same locality and date as for holotype, RMNH .INS.1722320 ( RMNH).

Diagnosis. Gnathochorisis sapaensis sp. nov. is characterized by the combination of the following characters: face orange, clypeus yellow ( Fig. 1C ); antenna with 21 flagellomeres, first flagellomere 3.0 × as long as wide; pronotum partly orange; metapleuron smooth ( Fig. 1G ); propodeum with area superomedia elongate, 1.4 × as long as wide ( Fig. 1E ); fore wing with vein 3rs-m present; first metasomal tergite 2.5 × as long as maximum width, with latero-median carinae present; second tergite granulate, 1.2 × as long as apical width ( Fig. 1H ); ovipositor 0.9 × as long as hind tibia.

Gnathochorisis sapaensis sp. nov. is similar to G. malaisei Humala, 2021 from Myanmar in having the metapleuron smooth, propodeum with area superomedia elongate, and fore wing with vein 3rs-m present, but differs by the shorter first flagellomere, which is 3.0 × as long as wide (5.3 × in G. malaisei ), dark frons (orbits yellow in G. malaisei ), and granulate second tergite of metasoma (longitudinally wrinkled anteriorly in G. malaisei ).

Description. Female. Holotype. ( Figs 1A, C, E–H ). Body length approximately 3.4 mm. Fore wing 2.9 mm.

Head ( Figs 1C, F–G ) smooth and densely pubescent. Antenna with 21 flagellomere, first flagellomere 3.0 × as long as wide. Face about 0.7 × as long as wide, sparsely punctate and with traces of granulation; eyes slightly divergent to clypeus, glabrous. Malar space long, 1.7 × the basal width of mandible; subocular sulcus present. Clypeus 0.8 × as long as wide, smooth. Mandible bidentate, not twisted, lower tooth shorter than upper tooth. Temples short and strongly narrowed behind eyes (dorsal view). Frons and vertex smooth and densely pubescent; length of the ocellar-ocular distance 1.3 × maximum diameter of lateral ocellus; occipital carina complete.

Mesosoma ( Figs 1E, G ) smooth and densely pubescent. Propleuron sparsely pubescent. Pronotum smooth; epomia present, but not reaching mesoscutum. Mesoscutum densely and evenly pubescent; notauli deep anteriorly, with vertical carina. Scutellum densely pubescent. Mesopleuron smooth, densely pubescent anteriorly and ventrally; epicnemial carina present; sternaulus deep on anterior 0.3 of mesopleuron. Metapleuron smooth, with some rugosities on the posterior edge; pleural and submetapleural carinae present. Propodeum smooth, carinated; area superomedia elongate, 1.4 × as long as wide, costulae present; area basalis not delimited by carinae anteriorly; apophyses present, but weak.

Legs relatively stout; hind femur 3.2 × as long as wide; third tarsomere of hind tarsus as long as fifth tarsomere; tarsal claws simple.

Wings. Fore wing with vein 2rs-m about 0.8 × the distance between 2rs-m and 2m-cu; vein 3rs-m present; vein 1cu-a opposite to M&Rs; hind wing with nervellus intercepted below the middle, inclivous; distal abscissa of Cu present.

Metasoma ( Fig. 1H ) granulate anteriorly and sparsely pubescent. First tergite 2.5 × as long as maximum width, granulate; latero-median carinae present. Second tergite 1.2 × as long as apical width, granulate. The remaining tergites smooth. Ovipositor 0.9 × as long as hind tibia.

Colour. Head black except face orange, clypeus, mandible (except apices), scape and pedicel yellow. Mesosoma black except propleuron ventrally, pronotum dorsally and ventrally, subtegular ridge orange, and tegula yellow. Fore and mid legs orange except coxae, trochanters and trochantelli yellow; hind leg orange except coxa largely, trochanter partly, femur except base, tibia except middle, and tarsus entirely fuscous. Metasoma with first tergite black; the remaining tergites brown, except second tergite apically, third tergite basally and apically yellow. Pterostigma and veins brown.

Male. Generally resembles female, but differs by the antenna with 22 flagellomeres, first flagellomere 3.8 × as long as wide; more abundant yellow colouration of head; shorter area superomedia, which is about 1.2 × as long as wide; and darker hind legs and third tergite of metasoma ( Figs 1B, D ).

Etymology. The specific epithet refers to the type locality closely situated to the city Sa Pa. Adjective.

Distribution. Vietnam.

Figures

FIGURE 1. Gnathochorisis sapaensis sp. nov. A, C, E–H—holotype female; B, D—paratype male; A–B—lateral view of habitus; C–D—frontal view of face; E—dorsal view of propodeum; F—dorsal view of head; G—lateral view of head, mesosoma and first metasomal tergite; H—dorsal view of metasomal tergites 1–2. Scale bars: 0.5 mm (A–B) and 0.1 mm (C–H).