Holotype, ♀ (ZUH), “S. China: Hunan, nr Zhangjiajie, Badagong Mts, Tian Ping Mt., 9–13.vii.2009, 550 m, Xi-Ying Li, RMNH’10”, “CVA4241, sp. 7”. Paratype, 1 ♂ (RMNH), same locality label data.

Vein 1r-m of hind wing 0.7–1.0 times as long as vein 1-M (Fig. 352); posterior groove of pronotal side and anterior groove of metapleuron crenulate (Fig. 351); ventral half of posterior groove of pronotal side crenulate; first tergite normal; medio-posterior depression of mesoscutum present (Fig. 353); vein m-cu of fore wing slightly longer than vein 2-SR+M (Fig. 352); basal cell of hind wing wide and vein 1r-m of hind wing 0.8-1.0 times as long as vein 1-M (Fig. 352); second and third tergites smooth (Fig. 354).

Holotype, ♀, length of body 2.5 mm, of fore wing 2.6 mm.

Head. Antenna with 24 segments and as long as fore wing; third segment 1.3 times as long as fourth segment, length of third, fourth and penultimate segments 2.5, 2.0 and 1.6 times their width, respectively (Figs 356, 357); length of maxillary palp 0.9 times height of head; labial palp segments normal; occipital carina rather close to hypostomal carina and dorsally absent; hypostomal carina narrow; length of eye in dorsal view 3.8 times temple; frons slightly depressed behind antennal sockets and glabrous, smooth; face smooth, medially elevated (Fig. 358); width of clypeus 2.1 times its maximum height and 0.55 times width of face; clypeus rather convex, slightly protruding forwards and largely smooth (except for some punctures) and its ventral margin slightly concave and obtuse (Fig. 358); hypoclypeal depression rather large (Fig. 360); malar suture deep; length of malar space 0.6 times basal width of mandible; mandible triangular and with narrow ventral carina (Fig. 359).

Mesosoma. Length of mesosoma 1.2 times its height; dorsal pronope large, deep and round (Fig. 362); pronotal side largely smooth, but posterior groove entirely crenulate and oblique groove with some crenulae (Fig. 351); epicnemial area mainly smooth dorsally, with some minute punctures; precoxal sulcus medially oblique and moderately crenulate (Fig. 351); rest of mesopleuron smooth; pleural sulcus smooth; mesosternal sulcus deep and finely crenulate; anterior groove of metapleuron crenulate; notauli absent on disc, only anteriorly with pair of short smooth impressions (Fig. 353); meso-scutum glabrous and strongly shiny; medio-posterior depression of mesoscutum round and medium-sized in a shallow longitudinal impression (Fig. 353); scutellar sulcus widely crenulate; scutellum slightly convex medially, smooth; propodeum with short medio-longitudinal carina and irregular coarsely reticulate-rugose (Fig. 353).

Wings. Fore wing (Fig. 352): pterostigma triangular; 1-R1 ending at wing apex and 1.5 times as long as pterostigma; r:3-SR:SR1 = 2:23:32; 2-SR:3-SR:r-m = 14:23:6; r slender; 1-M and SR1 slightly curved; m-cu far postfurcal; cu-a interstitial; first subdiscal cell closed, CU1b rather long; apical third of M+CU1 sclerotized. Hind wing (Fig. 352): M+CU:1-M:1r-m = 3:2:2; cu-a straight; m-cu present as faint unpigmented trace.

Legs. Length of femur, tibia and basitarsus of hind leg 4.5, 9.0 and 7.0 times as long as wide, respectively; hind femur with long and tibia with medium-sized setae (Fig. 355).

Metasoma. Length of first tergite 1.1 times its apical width, its surface convex and densely reticulate-rugose, its dorsal carinae united at apex of tergite (in paratype at basal 0.3), straight (Fig. 354); second suture slightly indicated; second and third tergites smooth; length of setose part of ovipositor sheath 0.06 times fore wing and 0.2 times length of hind tibia (Fig. 361).

Colour. Black; antenna (but scapus yellowish laterally and ventrally) and metasoma (except first tergite) ovipositor sheath and pterostigma dark brown; clypeus and mandible largely chestnut-brown; palpi, tegulae and legs (but hind tarsus and telotarsi darkened) pale yellow; veins brown; wing membrane subhyaline.

Variation. The male paratype has length of fore wing 2.7 mm, antenna with 29 similar short antennal segments and 1.1 times as long as fore wing (Fig. 357), inner apex of hind tibia dark brown and vein 1r-m of hind wing 0.8 times as long as vein 1-M.

Molecular data. COI, 16S, 28S (CVA4241).

*China (Hunan).

Unknown.

Name derived from “obliquus” (Latin for “slanting”), because of the more or less oblique carinae of the propodeum.

The new species runs in the key by Chen and Weng (2005) to Opius aquacaducus Chen & Weng, 2005. Rogadopsis obliqua differs by having the width of the clypeus 2.1 times its height (about 3.1 times in Opius aquacaducus), the medio-posterior depression of the mesoscutum round (teardrop-shaped), the propodeum mainly irregularly coarsely reticulate-rugose (densely punctate), the length of malar space 0.6 times the basal width of mandible (0.9 times), the length of the eye in dorsal view 3.8 times the temple (equal) and the antenna with 24–29 segments (34–36 segments).

The long vein m-cu of the fore wing is shared with Rhogadopsis sculpta (Chen & Weng, 2005) comb. n., but Rhogadopsis sculpta has the anterior half of the notauli linearly impressed and nearly smooth, face laterally and dorsally yellowish-brown; malar space shorter, vein r of fore wing oblique, second submarginal cell of fore wing is more elongate.