Mesoleptidea nigra Li & Sun, 2024

Li, Tao, Li, Bin & Sun, Shu-Ping, 2024, Three new species of Mesoleptidea Viereck (Hymenoptera, Ichneumonidae) from China, Zootaxa 5397 (2), pp. 251-263 : 252-256

Mesoleptidea nigra Li & Sun , sp. nov.

Figures 1–14

Material examined. Holotype, Female, CHINA: National Forest Park of Mt Wawu, Hongya , Sichuan Province, N 29°40´, E 102°59´, 1180 m; 13 September 2019, IT by Gui-Ru Kang, CBDPC.

Diagnosis. Clypeus almost shiny, with weak, indistinct punctures. Scutellum trapezoidal. Tergite 1 uniformly arched ( Fig. 12 ). Tergite 2 1.3 × as long as posterior width ( Fig. 13 ). Tergite 3 longer than its maximum width. Ovipositor sheath distinctly narrowed posteriorly. Face and clypeus whitish yellow. Mesosoma and metasoma almost entirely black.

Description. Female ( Fig. 1 ). Body length about 9.7 mm. Fore wing about 8.0 mm. Ovipositor sheath about 0.5 mm.

Head. Face approximately 1.5 × as wide as long, shining with fine granular microsculpture and dense setae, median portion evenly convex ( Fig. 2 ). Clypeus 2.7 × as wide as long, convex from basal to subapical portions, shining with sparse setae; apical margin truncate ( Fig. 2 ). Mandible large and long, with dense setae medially; lower tooth as long as upper tooth ( Fig. 2 ). Malar space shiny, about 0.6× as long as basal width of mandible ( Fig. 4 ). Gena evenly convergent backward, with fine granular microsculpture and dense setae ( Fig. 4 ). Vertex with the same texture as gena ( Fig. 3 ). Postocellar line approximately 0.6 × as long as ocular-ocellar line. Frons slightly concave, with the same texture as vertex. Antenna with 37 flagellomeres; ratio of length from first to fifth flagellomeres: 2.3:1.3:1.2:1.1:1.0. Occipital carina complete, genal carina joining hypostomal carina above base of mandible.

Mesosoma. Pronotum shiny, dorsal half of concavity with fine oblique wrinkles and ventral half with irregular wrinkles; dorsal margin with dense setae ( Fig. 5 ). Epomia absent. Mesoscutum convex, shiny, with dense setae; posteromedian part with coarsely granulate ( Fig. 6 ). Notaulus distinct on anterior portion of mesoscutum. Scuto-scutellar groove deep, shiny, with fine setae. Scutellum distinctly convex, shiny, with dense setae ( Fig. 6 ). Mesopleuron almost flat, shiny; median portion with fine indistinct irregular wrinkles; speculum shiny ( Fig. 5 ). Dorsal end of epicnemial carina closing anterior margin of mesopleuron, reaching to subtegular ridge. Metapleuron slightly convex, shiny, with fine granular microsculpture; submetapleural carina strong. Wings hyaline ( Fig. 7 ). Fore wing vein 1cu-a distal to M&RS by 0.2 × length of 1cu-a. Areolet forming an oblique triangle, with short petiole, receiving vein 2m-cu almost at its lower posterior corner ( Fig. 8 ). Postnervulus intercepted almost at middle. Hind wing vein 1-cu 4.0 × as long as cu-a. Ratio of length of hind tarsomeres from first to fifth: 4.1:2.2:1.6:1.0:1.3 ( Fig. 9 ). Propodeum convex, shagreened, with dense long setae; basal median portion deeply reniform concave; median portion with irregular fine wrinkles; apico-median portion shiny, with longitudinal 0.2 of propodeum ( Fig. 10 ).

Metasoma. Tergite 1 approximately 7.6 × as long as anterior width, 3.7 × as long as posterior width ( Fig. 11 ); shiny, with fine reticulate texture and dense setae; latero-median carinae absent; dorso-lateral carinae interrupted after spiracle ( Fig. 12 ); ventro-lateral carinae complete; spiracle circular, located at middle of tergite. Tergite 2 approximately 1.8 × as long as anterior width, 1.3 × as long as posterior width; shagreened, anterior and posterior margins shiny; thyridium almost circular, concave ( Fig. 13 ). Tergite 3 shiny, with evenly dense micro-setae ( Fig. 13 ). Ovipositor sheath 7.0 × as long as its width ( Fig. 14 ). Ovipositor strong, compressed, with subapical dorsal notch.

Coloration ( Fig. 1 ). Black, except the following: face except upper median dark brown spot, clypeus, mandible except dark reddish brown teeth, malar space, lower portion of gena, maxillary and labial palpi, antenna except dorsal of scape and pedicel and basal half of flagellum brown to dark brown, upper-posterior corners of pronotum, antero-lateral portion of mesoscutum, tegulae, fore and mid legs, lateral margins of tergites 2–6, sternites 2–6 except lateral longitudinal bands dark brown, whitish yellow. Apical margin of hind coxa, trochantellus, tibia and tarsus brown; trochanter dark brown; femur reddish brown. Wings slightly infuscate. Pterostigma except median portion yellowish brown, veins and ovipositor sheath dark brown. Body with yellowish brown setae.

Male. Unknown.

Distribution. CHINA: Sichuan ( Fig. 42 ).

Etymology. The specific name is derived from the mesosoma being almost entirely black.

Differential diagnosis. The new species is similar to M. stalii (Holmgren, 1858) from Europe, but can be distinguished from the latter by the following combination of character states: fore wing with vein 1cu-a distal to M&RS by 0.2 × length of 1cu-a; tergite 1 uniformly arched, slightly shagreened ( Figs 11, 12 ); face whitish yellow; mesosoma almost entirely black; and hind leg black. Mesoleptidea stalii differs as follows: fore wing with vein 1cua opposite M&RS; tergite 1 almost straight, smooth; face black; pronotum, mesoscutum with large yellow flecks; posterior portion of scutellum yellow; and hind coxa red to red brown.

Figures

FIGURE 42. Distribution map of Mesoleptidea species of China (map from: http://bzdt.ch.mnr.gov.cn).

FIGURES 1–3. Mesoleptidea nigra Li & Sun, sp. nov., ♀, holotype (CBDPC). 1 Habitus, lateral view. 2 Head, anterior view. 3 Head, dorsal view. Scale bars: 1 = 2.0 mm; 2 = 0.3 mm; 3 = 0.2 mm.

FIGURES 4–9. Mesoleptidea nigra Li & Sun, sp. nov., ♀, holotype (CBDPC). 4 Head, lateral view. 5 Mesosoma, lateral view. 6 Mesoscutum and scutellum, dorsal view. 7 Fore wing. 8 Areolet. 9 Hind tarsus. Scale bars: 4–6= 0.3 mm; 7, 9 = 0.5 mm; 8 = 0.2 mm.

FIGURES 10–14. Mesoleptidea nigra Li & Sun, sp. nov., ♀, holotype (CBDPC). 10 Propodeum. 11 Tergite 1, dorsal view. 12 Tergite 1, lateral view. 13 Tergites 2–3, dorsal view. 14 Apical portion of metasoma, lateral view. Scale bars: 10–12, 14 = 0.3 mm; 13 = 0.5 mm.