Xiphovelia vietnamica sp. nov.

(Figs. 1, 2, 9, 10, 11, 12, 13, 18)

Type material. Holotype: apterous male, VIETNAM, Quang Binh Prov., Minh Hoá district, Hong Hoá (17°47'N, 105°55'E), 29.V.2015, coll. Zhen Ye (NKUM). Paratypes: 2 apterous males, 1 apterous female, same data as holotype (NKUM).

Diagnosis. X. vietnamica sp. nov. is similar to X. glauca Esaki & Miyamoto, 1959, with the connexiva in females erect and the posterior half with relatively long bristles (Fig. 2). However, this species can be distinguished by the relatively small body size (body length: apterous male 1.50–1.52 and apterous female 1.65; in X. glauca, body length: apterous male 1.70–1.80 and apterous female 1.90–2.00). In males of X. vietnamica sp. nov., the metanotum has a pair of distinctly silvery hair markings (Fig. 1) and abdominal segment VIII (Fig. 12) is about 1.35 times as long as wide (in X. glauca, the metanotum does not have a pair of distinctly silvery hair markings and abdominal segment VIII is about 1.25 times as long as wide). In females of X. vietnamica sp. nov., the ventral surface of the legs are almost whitish.

Description. Apterous male (Fig. 1). Colour: ground colour brownish; head dorsum blackish, ventrally grayish, clypeus shining yellow, labrum shining black, rostrum yellowish brown with black apex; antennal segments I–III brownish, IV brown; pronotum with a clear yellow-brown transverse band, meso- and metanotum black, with a pair of rounded, silvery hair markings distinct on both nota (Fig. 1); legs yellowish with apices of femora, tibiae and tarsi weakly infuscated (Figs. 9–11), apical half of fore femur ventrally with blackish patches (Fig. 9); abdomen dorsally black, medial parts of mediotergites V–VII, lateral parts of mediotergite II and laterotergites III and VI with silvery hair markings (Fig. 1); abdominal segment VIII and pygophore yellowish, each weakly infuscated apically (Figs. 12–13). Structural characteristics: body length 1.50–1.52 (holotype: 1.50), greatest width 0.65–0.66 (holotype: 0.65), body flat and oval, bearing short, grayish or silver, appressed pubescence; head short and wide, head length: 0.30–0.31, head width: 0.52–0.53, about 1.73 times head length; posteriorly inserted into medially concave anterior margin of pronotum; labrum triangular; eyes globose, laterally reaching beyond anterior pronotal angles and adjacent to anterior margin of pronotum; antenna about 0.54 times as long as body, lengths of antennal segments I–IV: 0.17, 0.18, 0.21, 0.30, segment I stout, segments II–IV relatively slender but not flagelliform; pronotum short and transverse, width: 0.55–0.56, length: 0.10–0.11, about 5.5 times as wide as long; mesonotum transverse and largest of nota, broadly fused with metanotum medially; legs with mainly decumbent, short setae except middle tibia ventrally with relatively long, erect setae (Fig. 10); fore femur (Fig. 9) straight and thick in middle, fore tibia (Fig. 9) slightly curved in apically, length of grasping comb 0.12, about 0.32 times tibia length; middle trochanter (Fig. 10) longest and most slender of trochanters, middle femur (Fig. 10) almost straight and thinnest of femora; middle tibia (Fig. 10) thickened in middle, with row of about 7–8 long erect bristles along inner margin; leaf-like pretarsal claws and ventral arolium emanating from middle tarsal segment II subapically; hind femur (Fig. 11) stout and narrowed toward both ends, hind tibia (Fig. 11) straight and longer than that of middle leg; lengths of leg segments (trochanter, femur, tibia and tarsus): fore leg: 0.17, 0.40, 0.38 and 0.18, middle leg: 0.22, 0.51, 0.44 and 0.43 (0.18+0.26), hind leg: 0.16, 0.50, 0.51 and 0.25 (0.08+0.17); abdomen dorsally narrowed caudad, connexiva narrow and slightly raised. Genital segments: abdominal segment VIII (Fig. 12) about 1.35 times as long as wide, posterior margin with short, sparse, erect, black-brown hairs; pygophore (Fig. 13) swollen ventrally and with a relatively small, broad, ear-like process on each side; paramere rudimental and small.

Apterous female (Fig. 2). Body slightly longer and greatly wider than male, ventral surface of legs almost whitish, other coloration and markings similar to that of male; body length: 1.65, greatest width: 0.84; structure of head including antennae as in male, head length: 0.34, head width: 0.54, about 1.59 times head length, antenna about 0.51 times as long as body, lengths of antennal segments I–IV: 0.19, 0.20, 0.21, 0.30; pronotum width: 0.56, length: 0.10, about 5.60 times as wide as long; legs similar to those of male except fore tibia without grasping comb, lengths of leg segments (trochanter, femur, tibia and tarsus): fore leg: 0.19, 0.40, 0.35 and 0.20, middle leg: 0.24, 0.55, 0.46 and 0.46 (0.20+0.26), hind leg: 0.20, 0.53, 0.55 and 0.30 (0.10+0.20); connexiva broader than in male, hind portion erect and posterior half with relatively long bristles (Fig. 2); genital segments retracted into abdomen.

Macropterous male and female: unknown.

Etymology. The specific name is derived from the type locality (Vietnam).

Distribution. Vietnam (Quang Binh) (Fig. 18).