Description:
Male: Head width is 2.6 times greater than its length, and wider than the thorax. The vertex behind the ocelli abruptly curves. The frons is smooth with longitudinal grooves. The gena has longitudinal grooves arranged in a fan shape. The compound eyes are smooth. The distance between the posterior ocelli and the anterior ocellus is less than the distance between the posterior ocellus and the compound eye.
The antenna has 12 segments. Beginning from the third segment, there are long hair whorls (the length of the hairs is approximately 4 times greater than the width of the antennal segment, except for the last two segments). Furthermore, antennal segments from the fourth segment onwards are spindle-shaped, segments 5 and 11 have one thickened area, and segments 6-10 have two thickened areas. The scape is 4.5 times longer than the second antennal segment and 4.5 times longer than the radicle.
The second antennal segment does not have long, thick hair whorls. Its length is 5 times greater than its width, and longer than the third antennal segment. The second and third antennal segments do not have thickened bumps. The third antennal segment has 2 long hair whorls, and its length is 3 times greater than its width. Antennal segments 4, 5, 11 and 12 each have one long hair whorl. Segments 6-10 each have 2 long hair whorls. The hairs forming the hair whorls of segments 11 and 12 are shorter than the hairs on the preceding segments. The lengths of antennal segments 3-12 are as follows: 6: 11: 14: 15: 15: 10: 10: 10: 6: 6. Antennal segments 6-10 are generally very long; segments 6-9 are 8 times longer than their width. Segment 10 is 5 times longer than its width. Segments 11 and 12 are twice as long as their width.
The thorax has approximately the same length and width. The posterior half of the mesoscutum has two short longitudinal grooves. The scutellum is rounded and lacks protuberances. The forewing is broad, more than 2.5 times longer than its width, and 2.5 times longer than the width of the thorax. The marginal vein of the forewing is almost 3 times longer than the stigmal vein.
The abdomen’s shape, the relationship between segments, and the venation are similar to those of Xenomerus forax Kozlov et Le.
The body is black. The scape and the second antennal segment are brownish-yellow; the remaining antennal segments are dark brown. The coxae are brown, and the remaining leg segments are brownish-yellow.
Size:
Body length 1.1mm.
Distribution:
Vietnam: Hoa Binh.
Type specimen:
1 male (holotype), Hoa Binh (Kim Boi, Thuong Tien) (forest) 8/11/1978 (Le Xuan Hue).