Stenaoplus albistriatus, Riedel, 2023

Riedel, Matthias, 2023, Notes on Ichneumoninae (Hymenoptera, Ichneumonidae) from southern China, with descriptions of one new genus and twelve new species, Contributions to Entomology 73 (2), pp. 223-248 : 223

Stenaoplus albistriatus sp. nov.

Figs 44-47

Type material.

Holotype: (♀) China, Yunnan, Gongshan 10 km NW, 27.798°N, 98.583°E, 2100 m elev., 12.VI.2009, leg. Blank, Liston & Taeger.

Etymology.

The species name refers to the apical whitish (Latin “albus”) bands of the tergites.

Description.

Female. Body length 10 mm. Flagellum with 32 segments, slender and bristle-shaped; 1st flagellar segment 5.0 × as long as wide; widest segments about square. Temple distinctly and roundly narrowed behind eye. OED 1.0 × and OOD 1.1 × ocellar diameter. Frons finely rugose-punctate. Face densely punctate, shining. Clypeus moderately convex, 2.1 × as wide as long, densely punctate; apical margin sharp and slightly rounded. Mandible long, strongly narrowed behind base, with two small teeth; ventral tooth smaller than dorsal tooth and distinctly bent inwards (by 75°). Malar space 0.8 × as long as width of mandibular base. Gena densely punctate ventrally. Genal carina reaching hypostomal carina far from mandibular base, both carinae low.

Notaulus impressed on anterior 0.4 of mesoscutum. Mesoscutum with fine and dense punctures and distinct granulation, dull. Mesopleuron and metapleuron densely and finely rugose-punctate; speculum partly smooth; juxtacoxal carina indicated by fine rugae. Scutellum distinctly raised medially, almost pyramidal in profile, slightly wider than long, with dense punctures and complete lateral carina. Propodeum rugose-punctate, spiracle slit-shaped. Area basalis without lateral carina, not bulging medially and without median tubercle. Area superomedia trapezoid (wider frontally than posteriorly), about as long as wide. Costula absent. Apical transverse carina with denticular elevation at posterolateral edge of area dentipara, but without distinct apophysis. Area petiolaris with transverse rugae and distinct lateral carina. Hind coxa finely and densely punctate, without scopa. Legs slender; hind femur densely punctate, 4.7 × as long as wide. External surface of hind tibia without denticular spines. Tarsal claws simple. Areolet quadrangular, pointed frontally; vein 2m-cu reaching its middle. Vein 1cu-a postfurcal by 2 × its width.

Metasoma oxypyygous. Postpetiole moderately widened, without latero-median carina, finely rugulose and dull. Gastrocoelus slightly impressed, granulate. Thyridium very large, oblique, 3.5 × as wide as interval between thyridia. 2nd to 4th sternites with median fold. 2nd tergite 1.2 × as wide as long. 2nd and 3rd tergites finely and densely rugose-punctate, dull. Following tergites with superficial punctures, ± shining. Ovipositor sheath slender, clearly reaching beyond metasomal apex (by length of 3rd hind tarsomere).

Colour. Black with extensive yellow colouration. Flagellar segments 8-12 ivory. Yellow are palps, mandible, except teeth, clypeus, face, gena, complete orbits, scape ventrally, frontal and upper margins of pronotum, round central spot of mesoscutum, subtegular ridge, large spot of mesopleuron, upper division of metapleuron, scutellum, postscutellum, spot covering apical metapleuron, area dentipara and area posteroexterna and apical bands of all tergites. Fore- and mid-coxae and trochanters yellow; hind coxa black with yellow dorsal spot, hind trochanter black, with yellow stripe; legs otherwise reddish; 4th and 5th hind tarsomeres brownish. Wings hyaline; pterostigma yellowish.

Male. Unknown.

Remarks.

This new species is a member of the genus Stenaoplus Heinrich as re-defined by Heinrich (1968b: 1110-1111) and runs to that genus in the key of Oriental Ichneumoninae ( Townes et al. 1961). It is characterised by the modified mandible which is distinctly narrowed behind base and slender medially and distally and resembles the mandibular form found in Benyllus Cameron, by its almost pyramidal scutellum and by a short blunt denticular lamella at the postero-lateral edge of area dentipara. From other known Oriental Stenaoplus species, it can be differentiated by the modified structure of the mandible and the colour pattern of the metasoma with yellowish posterior bands on all tergites.

Figures

Figures 44 - 47. Stenaoplus albistriatus sp. nov. HT: 44. Face, frontal view; 45. Head, dorsal view; 46. Propodeum, dorsal view; 47. Basal tergites dorsal view.