Holotype of Opius vittata, ♀ (FAFU), “[China:] Fujian, Jiangle, Longqi Mt., 10.VII.1994, Wu Zhi-shan” and 3 ♀ + 1 ♂ topotypic paratypes collected 10–14.VII.1994.

4 ♀ (RMNH, ZUH), “S. China: Hunan, Changsha, garden Hunan Agr. Univ., 80 m, 31.V.2009, Xi-Ying Li, RMNH’09”; 2 ♀, “S. China: Hunan, nr Zhangjiajie, Badagong Mts, Tian Ping Mt., 9-13.VII.2009, 550 m, Xi-Ying Li, RMNH’10”; 1 ♀, “S. China: Hunan, nr Zhangjiajie, Badagong Mts, Bamaoxi, 2-3.VI.2009, 540 m, Xi-Ying Li, RMNH’09”.

Vein SR1 of fore wing 3.4-4.0 times as long as vein 3-SR; clypeus depressed ventrally and narrow sickle-shaped (Fig. 233); mesosoma (except black meso-scutum) orange-brown; second and third metasomal tergite micro-sculptured and propodeum smooth; hypopygium of ♀ obtuse apically or nearly so and 0.1–0.2 times as long as metasoma; labrum normal, without large space below clypeus (Fig. 233); hind femur about 4.5 times as long as wide.

Specimen from Changsha, ♀, length of body 1.2 mm, of fore wing 1.4 mm.

Head. Antenna with 23 segments and 1.4 times as long as fore wing; third segment 1.1 times as long as fourth segment, length of third, fourth and penultimate segments 3.8, 3.5 and 2.5 times their width, respectively (Fig. 236); length of maxillary palp 0.8 times height of head; labial palp segments moniliform; occipital carina moderately far removed from hypostomal carina (Fig. 234) and dorsally absent; hypostomal carina narrow; length of eye in dorsal view 1.8 times temple; frons slightly evenly convex and glabrous, smooth; face smooth, medially hardly elevated (Fig. 233); width of cly-peus 3.5 times its maximum height and 0.6 times width of face, depressed ventrally and sickle-shaped (Fig. 233); clypeus slightly convex, distinctly protruding forwards, smooth except for a few punctures and its ventral margin thick and slightly concave; hypoclypeal depression wide (Fig. 233); malar suture shallow, linear; mandible slender triangular and somewhat narrowed submedially, with a narrow ventral carina (Fig. 234).

Mesosoma. Length of mesosoma 1.1 times its height; dorsal pronope obsolescent, pit-shaped; pronotal side smooth and posterior groove absent; epicnemial area smooth dorsally; precoxal sulcus medially superficially impressed, smooth as rest of mesopleuron; pleural sulcus smooth (Figs 225, 226, 227); mesosternal sulcus deep and narrow and smooth; notauli absent on disc, only anteriorly with pair of short smooth impressions (Fig. 230); mesoscutum glabrous and strongly shiny; medio-posterior depression of mesoscutum absent; scutellar sulcus narrow and finely crenulate; scutellum slightly convex medially; surface of propodeum smooth, except for crenulae posteriorly (Fig. 230).

Wings. Fore wing (Figs 228, 229): pterostigma elongate elliptical; 1-R1 reaching wing apex and 1.1 times as long as pterostigma; r:3-SR:SR1 = 2:12:48; 2-SR:3-SR:r-m = 8:12:4; r slender; 1-M straight and SR1 nearly straight; m-cu and cu-a slightly postfurcal; 1-CU1 hardly widened; first subdiscal cell open, CU1b absent; apical fifth of M+CU1 sclerotized. Hind wing (Fig. 229): M+CU:1-M:1r-m = 2:4:1; cu-a straight; m-cu absent; basal cell very narrow.

Legs. Length of femur, tibia and basitarsus of hind leg 4.5, 7.3 and 4.5 times as long as wide, respectively; hind femur and tibia with medium-sized setae (Fig. 232).

Metasoma. Length of first tergite 0.9 times its apical width, its surface flattened and coriaceous, matt and dorsal carinae developed in basal 0.4 of tergite (Fig. 231); second suture obsolescent; second and following tergites smooth; length of setose part of ovipositor sheath 0.07 times fore wing and 0.2 times length of hind tibia (Fig. 235).

Colour. Yellowish-brown; antenna (but scapus yellowish), stemmaticum, mesoscutum, pronotum dorsally, ovipositor sheath, third and following tergites, pterostigma and veins dark brown; palpi, mandible, tegulae and legs (but hind tibia apically, hind tarsus and telotarsi darkened) pale yellow; scutellum and metanotum brown; wing membrane subhyaline.

Variation. Length of body 1.2-1.4 mm, of fore wing 1.4-1.6 mm, antenna of ♀ with 23 (1) segments; vein SR1 of fore wing 3.4-4.0 times as long as vein 3-SR; thirds tergite smooth or superficially granulate; metasoma sometimes nearly completely yellowish-brown dorsally; melanistic specimens with body largely dark or chestnut brown occur (Figs 226, 227).

Molecular data. COI, 16S, 28S (CVA4239).

*China (Hunan).

Unknown.

Name derived from “depressus” (Latin for “pressed down”), because of the narrow depressed clypeus.

Phaedrotoma depressa runs in the key by Chen and Weng (2005) to Opius clusilis Weng & Chen, 2005. Phaedrotoma depressa differs by having the mandible gradually narrowed and nearly symmetrical (abruptly narrowed and asymmetrical in Opius clusilis), the head roundly narrowed behind eyes in dorsal view (directly narrowed), the mandible hardly widened basally (mandible distinctly widened), length of the first tergite 0.9 times its apical width (1.4 times) and length of the third antennal segment 3.8 times its width (2.6 times). Phaedrotoma rugulosa (Chen & Weng, 2005) comb. n. comes very close but has a higher clypeus (narrower), slenderer third and fourth antennal segments of ♀, T3-6 membranous and depressed posteriorly. Examination of the holotype of Opius vittatus Chen & Weng, 2005 (a junior homonym) showed that this is the same species as Phaedrotoma depressa despite it is not keying out to it.