Piasites nigricollis, Bordera & Santos, 2022

Bordera, Santiago & Santos, Bernardo F., 2022, A review of Piasites Seyrig (Hymenoptera, Ichneumonidae, Cryptinae), with description of seven new species, Journal of Hymenoptera Research 90, pp. 23-57 : 23

Piasites nigricollis sp. nov.

Figs 2A , 6 , 12E , 13D, F 14C

Diagnosis.

Piasites nigricollis sp. nov. can be distinguished from all other Piasites species by the combination of the following characters: pronotum shallowly and longitudinally strigose, ventrally smooth (Figs 6C , 13D ); mesoscutum evenly convex, mostly smooth and shiny with fine punctures on median lobe (Figs 6C, D , 13D ); mesopleuron mostly smooth and shiny, shallowly rugulose punctate at dorsal anterior corner, ventral anterior part shallowly punctate (Figs 6C , 13D ); propodeum strongly rugose punctate (Figs 2A , 13D ); propleuron, anterior part of pronotum and mesoscutum brownish black, ocular orbits completely white cream (Figs 6C, D , 13D ). Additionally, male with metapleuron smooth to shallowly rugulose punctate (Fig. 13F ).

Description.

Female. Fore wing length about 6.8 mm.

Head. In dorsal view, moderately narrowed behind eyes, about 0.55 × as long as wide. Gena in dorsal view rounded, weakly swollen. Posterior ocellus separated from eye about 1.55 × its maximum diameter. Distance between posterior ocelli 1.1 × their diameter. Occipital carina complete, evenly curved dorsally. Face smooth and shiny, slightly convex in the central part with very fine setiferous punctures. Clypeal suture weak, only present laterally. Clypeus about 1.6 × as broad as medially long, very convex with relatively long setae in the central part, prominent in lateral view, ventral margin rounded, with a very weak median denticle. Malar space about 0.8 × as long as basal mandibular width. Mandible 1.60 × as long as basal width; dorsal tooth distinctly longer than ventral one. Antenna with 28 flagellomeres, strongly tapered towards apex; flagellomeres from f11 to apex conspicuously flattened ventrally; f1 about 8.6 × as long as its maximum width.

Mesosoma. Pronotum shallow and longitudinally strigose, ventrally becoming smooth; epomia strong and relatively long, straigth, crossing the anterior depression of pronotum. Mesoscutum 1.05 × as long as wide, evenly convex, predominantly smooth and shiny, with fine and dense setiferous punctures on median lobe, lateral parts smooth; notaulus deep and narrow, with very small and inconspicuous transverse keels. Scutellum rugulose anteriorly, smooth posteriorly, lateral carinae strong, reaching 0.7 its anterior length. Mesopleuron predominantly smooth and shiny, shallowly rugulose punctate at dorsal anterior corner, ventral anterior part shallowly punctate; sternaulus deep, with very small transverse keels; epicnemial carina very weak, reaching the subtegular ridge. Metapleuron shallowly transverse strigose punctate; juxtacoxal and submetapleural carinae strong and complete. Propodeum strongly rugose punctate; anterior and posterior transverse carinae complete, centrally angled towards anterior part, parallel; posterior transverse carina forming two low lateral crests. Hind leg with femur about 6.1 × as long as high. Areolet pentagonal, about 0.7 × as high as wide, relatively small, 0.7 × as high as abscissa of vein 2m-cu above bulla. Hind wing with vein cu-a about 0.5 × length of first abscissa of CU.

Metasoma. T1 about 2.45 × as long as posteriorly broad, granulate, strongly curved dorsally in lateral view, dorso-lateral carina very weak, only present at postpetiole. T2 about 0.85 × as long as posteriorly broad, finely granulate as the following tergites. Ovipositor sheath about 0.55 × as long as hind tibia.

Colour. Body mostly orange. Head yellow cream; mandibular teeth, ocellar triangle and central part of occiput, scape and pedicel brownish black; f1-3 orange, following flagellomeres dark brown, f5-10 white. Mesosoma with propleuron, dorso-lateral part of pronotum and anterior part of mesoscutum, brownish black; subventral spot on pronotum and subtegular ridge yellow cream. T4 dorsally, and anterior part of T5 and T6, black; posterior part of tergites T5 and T6 and following tergites yellow cream. Wings hyaline, slightly yellowish, pterostigma yellow.

Male. Fore wing length about 7.7 mm. Head. Posterior ocellus separated from eye about 1.45 × its maximum diameter. Distance between hind ocelli about 1.15 × maximum diameter of posterior ocellus. Clypeus about 1.65 × as broad as medially long. Malar space about 0.7 × as long as basal mandibular width. Antenna with at least 24 flagellomeres, flagellum not enlarged subapically; flagellomeres from f17 to apex flattened ventrally; f1 about 6.0 × long as its maximum width. Mesosoma. Scutellum anteriorly punctate. Metapleuron shallowly rugolose punctate. Posterior transverse carina of propodeum evenly curved centrally. Hind leg with femur about 5.45 × as long as high. Areolet about 0.7 × as high as wide, 0.75 × as high as abscissa of vein 2m-cu above bulla. Hind wing with vein cu-a 0.55 × as long as first abscissa of CU. Metasoma. T1 about 3.2 × as long as posteriorly broad. T2 about 1.2 × as long as posteriorly broad. Colour. As in female, but antenna with white band from apex of f7 to f15. Other features as in female.

Etymology.

From the Latin collum, meaning “neck”, in reference to the black-coloured pronotum and anterior part of mesoscutum.

Material examined.

1 ♀ 1 ♂. Holotype: Madagascar • ♀; Ivondro; Museum Paris; VII-40; A Seyrig; MNHN . Paratype: Madagascar • 1♂; same collection data as for holotype; VIII-40; MNHN .

Figures

Figure 2. Propodeum of Piasites, dorsal view, females (II): A P. nigricollis sp. nov. (holotype) B P. orbitalis sp. nov. (holotype) C P. lineatus sp. nov. (paratype) D P. seyrigi sp. nov. (paratype). Scale bars: 0.3 mm.

Figure 6. Piasites nigricollis sp. nov., female (holotype): A habitus, lateral view B head, front view C head and mesosoma, lateral view D head and mesoscutum, dorsal view E metasoma, dorsal view F front wing, areolet and vein 2 m-cu. Scale bars: 1 mm (A); 0.5 mm (C, E); 0.3 mm (B, D, F).

Figure 12. Piasites species, habitus of males, lateral view: A P. carinatus B P. quasimodus sp. nov. (paratype) C P. seyrigi sp. nov. (paratype) D P. perinetensis sp. nov. (paratype) E P. nigricollis sp. nov. (paratype). Scale bars: 1 mm.

Figure 13. Piasites species, males A-E head and mesosoma, lateral view: A P. carinatus B P. quasimodus sp. nov. (paratype) C P. seyrigi sp. nov. (paratype) D P. nigricollis sp. nov. (paratype) E P. perinetensis sp. nov. (paratype) F-G metapleuron: F P. nigricollis sp. nov. (paratype) G P. perinetensis sp. nov. (paratype). Scale bars: 0.5 mm (A-E); 0.2 mm (F, G).