Arge planifrons Gussakovskij, 1935

21. Arge planifrons Gussakovskij, 1935

( Fig. 30 View FIGURE 30 )

Arge planifrons Gussakovskij, 1935: 237 (key), 280 (description), 407 (key), 425–426 (description), ♀; Taeger et al. 2010: 136.

Current status. Arge planifrons Gussakovskij, 1935 .

Type locality. China, Sichuan, Kangting.

Holotype: ♀, <golden circle> // Сычуань, ТацЗинлу [ China, Sichuan, Kangting , 30°02'N 101°57'E], 24.05.[18]93, Потанинъ [leg. G.N. Potanin] // Arge planifrons sp. nov., ♀, Gussakovskij det. // DEI-GISHym 89443 // GoogleMaps HOLOTYPUS, Arge planifrons Guss., 1935 , ♀, teste A. Taeger 2018 // Zoological Institute St. Petersburg INS_HYM_0001927 [ ZISP] .

Description. Female ( Fig. 30 View FIGURE 30 ). Body length 8.4 mm; fore wing length 8.4 mm.

Colour. Body black; head, thorax and apex of abdomen with blue-green, other parts with blue metallic lustre. Flagellum reddish. Fore tibiae and tarsi dark brown. Middle and hind tibiae yellow-white. Two apical tarsomeres of middle tarsus, most part of hind tarsus except base of first tarsomeres and apex of hind tibiae up to preapical spurs black. Wings hyaline, under pterostigma with dark spot. Vein C and base of vein A yellow, rest of veins and pterostigma brown. Pubescence yellowish-white.

Head. Head behind eyes strongly constricted. Distance between eyes 1.2 × vertical diameter of eye; eye with vertical diameter 1.8 × its horizontal diameter. Postocellar area not convex, with lateral furrows. POL: OCL: OOL as 1.3: 1.0: 1.6. Medial fovea broad, flat, with rounded pit in upper part, open towards frontal area. Lateral carinae sharp, nearly parallel, almost not converging downwards. Supraclypeal area not convex, shining, evenly punctuated, without median carina. Malar space nearly equal diameter of frontal ocellus. Clypeus smooth, shiny, sparsely punctate, with distinct medial semi-circular notch on ventral margin. Labrum with weakly concave ventral margin.

Antennae. Antennal length 1.4 × maximum head width; flagellum weakly curved at base, thickened toward apex, apex broadly rounded; its setae short, dense, closely adherent.

Thorax. Mesopleurae in lower part with glabrous band; scutellum flat, narrowly broadly at apex.

Legs. Middle and hind tibia with preapical spurs; tibial spurs simple. Basal tarsomeres of hind tarsus longer than next three combined.

Wings. In fore wing, cell 3Rs with anterior margin about equal to posterior margin, expanded to external margin. Vein 3r-m roundly curved. Veins B and M of fore wing join up at same point on vein R. Membrane of cell 1Rs densely covered with long setae. Wing margin between veins M and Cu not ciliate, without glabrous band along margin.

Abdomen. Abdomen almost parallel. Tergites in basal half shining, glabrous, in apical part densely pubescent. Saw sheath 1.7 × as long as wide, simple, parallel-sided, angularly at apex (ventral view); in lateral view triangular, tapered at apex, distinctly convex on ventral margin.

Lance in lateral view slightly convex, strongly tapered towards apex, medially with clearly visible annuli. Maximum width of lance equal to lancet width. Carina of apical part of dorsal margin with small indistinct denticles, remaining part of dorsal margin with longitudinal shallow fossa. Lancet with straight dorsal and slightly convex ventral margin. Annuli straight and perpendicular, in apical part indistinct. Annular spines (ctenidia) short, simple, several times shorter than width of annulus. Ventral margin with 18 well-distinct, strongly sclerotised serrulae. Serrulae triangular, oblique, with broadly rounded apex and small denticles. Between serrulae one long and straight pore canals of marginal sensilla.

Remark. The original description is given on a single specimen ( holotype). The males are unknown.