Drepanosticta siu

Male : A small Drepanosticta closely resembling D. bifida in general appearance, with a predominantly castaneous-brown colour pattern. Head with bluish-white labrum, mandibles, and anteclypeus; anterior margin of the labrum brownish black. The remaining parts of the head are brownish black, with transverse markings near the median ocellus and along the eyes. Antennae brownish black with pale pedicellus. The prothorax is castaneous. The posterior lobe bears paired processes that arise from a broad base and project backwards, but differ from D. bifida by the structure of the process and the absence of a subterminal ventral triangular projection. The synthorax is brown with darker and paler markings. Legs are dirty yellow with black markings at the joints. Wings are hyaline with brown venation and brown pterostigma. The abdomen is mostly castaneous-brown, with segments 8–10 dark brownish black. Segments 3–7 have pale basal annules and pale markings. Male anal appendages are diagnostic: the superior appendages are long and slender, with the upper margin hollowed and a very short denticle halfway along the inner side; the inferior appendages surpass the superior appendages and are straight except for a tapering tip curved inward. Female : Similar to the male, but the posterior pronotal processes are more delicate. Abdominal segments 9–10 are short, and the valves and terminal appendages are approximately as long as the anal appendages. The stylus is dark and slender.