Description:
Female: Head width is twice the length. The vertex behind the posterior ocelli does not abruptly bend, and there is no transverse ridge. The temple behind the compound eye is narrow. The posterior ocelli are close to the edge of the compound eye, with the distance between them not less than the diameter of the ocelli. The frons above the antennal scrobes is not concave, without transverse striations, and mostly smooth. The compound eyes are oval, with the length greater than the width (10:7). At 56x magnification, the compound eyes have short hairs. The vertex and gena have small granular texture. The antennae have 11 segments and are clavate. The scape is four times longer than its width. Antennal segment 2 is twice as long as its width and longer than segment 3. Segments 4 and 5 are longer than wide, with each segment shorter than segment 3. Segment 6 is shorter than segment 5, with the width greater than the length. The clava has 5 segments, and the total length of the claval segments is about three times their greatest width.
The thorax has equal length and width. The mesoscutum lacks a median groove and has small granular texture. The scutellum is mostly smooth. The forewing is approximately 2.5 times longer than its width and twice as wide as the thorax. The forewing has a postmarginal vein longer than the stigmal vein. The hindwing is normally narrow, with short posterior fringe hairs, the greatest length of which is no more than half the width of the wing.
The abdomen is 1.6 times longer than its width. Abdominal tergite 1 is about twice as wide as it is long. Tergite 2 is longer and wider than the other abdominal tergites, nearly as long as it is wide, and three times longer than tergite 1. The following tergites are progressively shorter and narrower. The ovipositor is exposed. The first tergite and the base of the second tergite have short longitudinal striations; the remaining part of the second tergite and the other tergites are smooth.
The body is black. The antennae are dark brown, with the scape yellowish-brown. The forelegs are black, the remaining leg segments are pale yellow.
Male: Similar to the female in shape and color. Antennae have 12 segments, filiform, with the terminal segments black, and the remaining antennal segments and legs yellow. The abdomen is ovate.
Size:
Body length approximately 0.7 mm.
Ecology:
Parasitic in the eggs of Chilo suppressalis (rice stem borer) and Scirpophaga incertulas (yellow rice stem borer).
Distribution:
Vietnam: Vinh Phuc, Quang Ninh, Hanoi, Ha Tay, Quang Nam, Binh Dinh, Long An.
Type Material:
Consists of numerous male and female specimens stored at the Institute of Ecology and Biological Resources (Hanoi).