Female: The head is approximately 1.5 times wider than its length. The vertex is posterior to the ocelli and compound eyes, without an abrupt bend. The postocular space is wide, its width equaling half the width of the compound eye. The posterior ocelli are close to the edge of the compound eye, with the distance between them equal to the diameter of the ocellus. The vertex and frons have a small honeycomb-like texture with small, white hairs. The frons above the antennal fossa is not concave. The cheeks have venation similar to that on the vertex, without fan-shaped venation. The compound eyes are oval-shaped, slightly rounded, with a length greater than their width (10:8). The length of the compound eye exceeds the length of the cheek.
The antennae are 12-segmented and clavate (club-shaped). The scape (first antennal segment) is approximately 5.5 times longer than wide and 3 times longer than the second antennal segment. The second antennal segment is longer than the third. The third antennal segment is wider than the second. The fourth antennal segment is wider than long, and subsequent segments widen gradually. The antennal club consists of 6 segments; the total length of the club segments is 4 times greater than their greatest width.
The thorax is longer than wide; the mesoscutum (mid-dorsal plate of the thorax) lacks a longitudinal groove. The surface of the thorax has venation similar to that on the vertex. The pronotal shoulders (sides of the prothorax) are flat; the humeral angles (shoulder angles) lack spines and are not pointed. The venation on the thorax resembles that on the vertex; the hairs at the base of the mesoscutum are smaller, finer, and denser than the hairs on the mesoscutum itself. The forewings are 2.7 times longer than wide.
The abdomen is as wide as the thorax and approximately 2.5 times longer than wide. The second tergite (dorsal abdominal segment) is slightly longer than the first tergite. The third tergite is longer and wider than the other tergites. The fourth tergite is longer than the second. The second and fifth tergites have the same length; the posterior tergites are about 2 times longer than the sixth tergite.
The body is black. The scape is brown; the remaining antennal segments range from dark brown to black; the compound eyes are whitish, tinged with yellow. The wings are slightly dull white, and the wing veins are brown. The legs are yellowish-brown.
Male: Similar to the female in shape and color. The male differs from the female by having 10-segmented antennae, without a club.
Size:
The body is approximately 4 mm long.
Distribution:
Vietnam: Thai Nguyen.
Type Material:
- 1 Female (holotype), Thai Nguyen (Phu Luong), 18/4/1986 (V. Triapitxun); paratypes: 15 Males, same location, 16-23/4/1986 (A. Sarkov and V. Triapitxun).