Polysphincta xena Khalaim, 2024

Khalaim, Andrey I., Ruíz-Cancino, Enrique & Coronado-Blanco, Juana María, 2024, Darwin wasps of the subfamily Pimplinae (Hymenoptera: Ichneumonidae) of Mexico: Polysphincta genus-group, Zootaxa 5458 (2), pp. 151-196 : 182-183

7. Polysphincta xena Khalaim , sp. nov.

Material examined. Holotype female ( TAMU), Mexico, Chiapas, 4 km W of San Cristobal [de las Casas], San Felipe [Ecatepec], 2200 m, oak-grass woodlands, 24–28.viii.1990, coll. R. Jones.

Description. Female). Body length about 7.8 mm.

Head in dorsal view with genae strongly narrowed behind eyes. Mandible twisted and strongly tapered towards apex, with lower tooth very small and short, the upper tooth much longer than the lower. Clypeus very weakly convex, with lower margin truncate centrally. Malar space about half as long as basal mandibular width. Face about as broad as high (measured from clypeal sulcus to the level of insertion of antenna), with median longitudinal convexity. Frons with distinct median longitudinal impression extending downwards from anterior ocellus. Lateral ocellus separated from eye by 0.75× its own maximum diameter. Face subpolished, weakly shining, impunctate. Frons polished, impunctate. Vertex polished, almost impunctate (with a few very small punctures peripherally). Gena polished, with very fine and sparse punctures.

Pronotum polished, impunctate, with medium-sized shelf-like projection. Epomia distinct. Mesoscutum polished, bare and impunctate. Notaulus very shallow, virtually absent. Scutellum convex, not laterally carinate. Epicnemial carina distinct, reaching to level of lower corner of pronotum. Mesopleuron polished, almost impunctate (with a few very small punctures centrally). Metapleuron convex, polished, with very fine and sparse punctures anteriorly. Submetapleural carina absent. Propodeum without carinae, with posterolateral impressions near hind margin, almost entirely polished and impunctate, posterolaterally with fine and sparse punctures. Pleural carina absent, but metapleuron separated from propodeum behind propodeal spiracle by furrow.

Fore wing length 5.8 mm. Vein 1cu-a (nervulus) somewhat distad base of M&RS (basal vein). Hind wing with nervellus distinctly intercepted in posterior 0.35, distal section of CU very weakly pigmented.

Metasoma with first tergite weakly and evenly broadened posteriorly, about 1.4× as long as posteriorly broad, weakly convex dorsally in lateral view; lateromedian carina distinct in anterior 0.35 of tergite; lateral longitudinal carina more or less developed, rounded in front of spiracle. First sternite weakly convex ventrally in lateral view, without projection. Tergites 2–4 subquadrate or very weakly elongate. Ovipositor short, slender, weakly upcurved apically, 0.9× as long as hind tibia and 0.95× as long as first and second metasomal tergites combined.

Head black, lower 0.6 of clypeus yellow. Mandible white with teeth brown. Mouthparts white. Antenna dark brown, scape and pedical ventrally with yellow marks. Propleuron and pronotum black, both near bases of fore coxae orange, pronotum also with upper posterior part widely orange and extreme posterior corner white. Mesoscutum, scutellum and postscutellum orange, mesoscutum with anterolateral sides widely white. Mesopleuron and metapleuron entirely orange. Propodeum black, posterolaterally slightly paler. Tegula white. Wings hyaline. Pterostigma pale brown. Legs predominantly white; hind coxa orange with white mark on outer side; all femora and tibiae partly orange; mid and hind tarsomeres brownish apically; hind femur with weak brownish marks subapically on anterior and posterior sides; hind tibia with weak brownish subbasal mark and partly darkened with brown apically. Metasomal tergites dark reddish brown, tergites 2–5 with posterior margins black. Sternites 2–5 with sclerotized lateral parts brown.

Male. Unknown.

Etymology. The name of this species is an arbitrary euphonious combination of letters, with no special meaning.

Distribution. Mexico (Chiapas).

Comparison. Polysphincta xena sp. nov. is only species of the genus in the Mexican fauna which has anterolateral sides of mesoscutum widely yellow and lacks submetapleural carina in combination. The new species is also characterized by having distinct epomia, pronotum with a medium-sized mediodorsal shelf-like projection, nervellus with distinct angulation in posterior 0.35, first sternite without projection ventrally, and a short ovipositor.

In the key to the Costa Rican species of Polysphincta ( Gauld et al. 1998: 42) , the new species runs to P. maskoi Gauld and P. purcelli Gauld in couplet 5, but may be distinguished from either by its first sternite without projection ventrally.