Symplecis nudus 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 : 578-580

Symplecis nudus Varga , sp. nov.

urn:lsid:zoobank.org:act:64F02AC7-3E32-4AB6-AC46-3093D9B0F6D1

( Fig. 5 )

Material examined. Holotype: ♀, VIETNAM: Tonkin , Hoang Lien N. R., 10 km SW Sa Pa, ca. 1550 m, Malaise traps, 22–29.x.1999, leg. C. v. Achterberg, RMHN’99, RMNH.INS.1722326 ( RMNH) . Paratypes: 2 ♀♀, same locality and date as for holotype, RMNH .INS.1722327, RMNH.INS.1722328 ( RMNH). Other material: 1 ♀, idem, but, 15 km W Sa Pa , ca. 1900 m, Malaise trap, 15–21.x.1999, leg. C. v. Achterberg, RMHN’99, RMNH . INS.1722329 ( RMNH).

Diagnosis. Symplecis nudus sp. nov. is characterized by the combination of the following characters: face and clypeus dark brown ( Fig. 5B ); antenna with 18–19 flagellomeres, first flagellomere 5.7–5.9 × as long as wide ( Fig. 5H ); pronotum orange ( Fig. 5D ); mesoscutum largely glabrous except of few setae anteriorly and along notaular lines ( Fig. 5E ); propodeum with area superomedia absent ( Fig. 5F ); fore wing with vein 3rs-m present; hind wing with nervellus not intercepted ( Fig. 5G ); first metasomal tergite 2.4–2.5 × as long as maximum width; second tergite longitudinally wrinkled, 1.4–1.5 × as long as apical width ( Fig. 5I ); ovipositor 0.4–0.5 × as long as first tarsomere of hind tarsus.

Symplecis nudus sp. nov. is similar to S. hoangliensis sp. nov. in having the area superomedia absent, but differs by the entirely glabrous meoscutum (densely pubescent centrally in S. hoangliensis sp. nov.) and slightly longer second tergite of metasoma, which is 1.4–1.5 × as long as apical width (1.3 × in S. hoangliensis sp. nov.). Symplecis nudus sp. nov. is similar to the Afrotropical S. glabroscutum Varga, 2023 and Holarctic S. glabra Dasch, 1992 in having entirely glabrous mesoscutum, but differs from both species by the not intercepted nervellus of the hind wing (intercepted below the middle in S. glabroscutum and S. glabra ). In addition, S. nudus sp. nov. differs from in S. glabroscutum by the slenderer antenna, with first flagellomere 5.7–5.9 × as long as wide (4.8 × in S. glabroscutum ) and darker second tergite of metasoma (entirely yellow in S. glabroscutum ). Symplecis nudus sp. nov. differs from S. glabra also by the reduced carination of the propodeum (area basalis and area superomedia enclosed by the carinae in S. glabra ).

Description. Female. ( Fig. 5 ). Body length approximately 2.9–3.0 mm. Fore wing 2.2–2.3 mm.

Head ( Figs 5B–D, H ) smooth and sparsely pubescent. Antenna with 18–19 flagellomeres, first flagellomere 5.7–5.9 × as long as wide. Face about 0.85–0.9 × as long as wide, smooth and sparsely pubescent; eyes strongly convergent to clypeus, glabrous. Malar space 0.3–0.4 × the basal width of mandible; subocular sulcus absent. Clypeus 0.7 × as long as wide, weakly granulate. Mandible bidentate, not twisted, lower tooth shorter than upper tooth. Temples short and strongly narrowed behind eyes (dorsal view). Frons and vertex smooth; length of the ocellar-ocular distance 1.1 × maximum diameter of lateral ocellus; occipital carina complete.

Mesosoma ( Figs 5D–F ) smooth and densely pubescent. Propleuron densely pubescent. Pronotum smooth and glabrous, weakly wrinkled posteriorly; epomia present, but not reaching mesoscutum. Mesoscutum sparsely pubescent anteriorly and along notaular lines; notauli deep anteriorly, with vertical carina. Scutellum smooth. Mesopleuron smooth, densely pubescent dorsally and ventrally; epicnemial carina present; sternaulus deep on anterior 0.4 of mesopleuron. Metapleuron shiny, with traces of granulation, and with longitudinal carina in lower third; pleural and submetapleural carinae present. Propodeum smooth, with traces of granulation, lateral longitudinal and apical transverse carinae present; apophyses present, but weak.

Legs relatively slender; hind femur 4.8–5.2 × as long as wide; third tarsomere of hind tarsus 1.1–1.2 × as long as fifth tarsomere; tarsal claws simple.

Wings ( Fig. 5G ). Fore wing with vein 2rs-m about 0.9–1.0 × the distance between 2rs-m and 2m-cu; vein 3rs-m present; vein 1cu-a weakly basad to M&Rs; hind wing with nervellus not intercepted, vertical; distal abscissa of Cu absent.

Metasoma ( Fig. 5I ) longitudinally wrinkled anteriorly and sparsely pubescent. First tergite 2.4–2.5 × as long as maximum width, longitudinally wrinkled laterally; latero-median carinae present, but weak. Second tergite 1.4–1.5 × as long as apical width, longitudinally wrinkled. The remaining tergites smooth. Ovipositor short, about 0.15 × as long as hind tibia and 0.4–0.5 × as long as first tarsomere of hind tarsus.

Colour. Head brown-black except mandible (except apices), scape and pedicel yellow. Mesosoma black except propleuron, pronotum, tegula and subtegular ridge orange. Fore and mid legs orange except coxae, trochanters and trochantelli yellow; hind leg orange except coxa apically, trochanter and trochantellus partly femur and tibia partly and tarsus entirely brownish. Metasoma with tergites 1–2 black; the remaining tergites brown, except second tergite apically, third tergite narrowly basally and apically yellow. Pterostigma and veins brown.

Male. Unknown.

Etymology. ‘Nudus’ from Latin means ‘naked’. The new species is named after the glabrous mesoscutum. Adjective.

Distribution. Vietnam.

Remark. One female has relatively longer first flagellomere, about 7.0 × as long as wide, but otherwise is similar to the holotype. This specimen has both antennae missing except for the first few flagellomeres, thus it was not included in the type seria.

Figures

FIGURE 5. Symplecis nudus sp. nov., holotype female. A—lateral view of habitus; B—frontal view of face; C—dorsal view of head; D—lateral view of head and mesosoma; E—dorsal view of mesoscutum; F—dorsal view of propodeum; G—lateral view of wings; H—frontal view of flagellomeres 1–2; I—dorsal view of metasomal tergites 1–3. Scale bars: 0.5 mm (A) and 0.1 mm (B–I).