Pseudagrion nigrofasciatum

Male : Pseudagrion nigrofasciatum is a blue-and-black species closely related to P. bengalense and P. microcephalum. The male has a blue head with a broad transverse black fascia extending across the ocelli and connecting with the eyes, enclosing large pale postocular spots. The synthorax is blue with extensive black markings; the antehumeral stripes are broad basally but narrowed posteriorly, while the lateral surface has a distinctive broad black fascia along the second lateral suture. The abdomen is mostly blue with black markings; segment 2 has a large squarish dorsal spot, and segments 3–6 have complete, strongly constricted black dorsal markings. Segments 8–9 are almost entirely blue. The superior anal appendages are deeply excavated with a rounded dilation before the middle, while the inferior appendages possess an acute median tooth. Female : The female is generally darker and less brightly coloured than the male. The head is yellowish-brown with a transverse dark marking and pale postocular spots. The synthorax is brown, without bluish or greenish intermingling, and is characterized by a broad black M-shaped dorsal marking. Unlike P. bengalense, the female lacks a black stripe on the posterior side of the synthorax. The abdomen is mainly dark brown to black with reduced pale markings; segment 2 bears a vase-shaped marking, while segments 3–9 have complete black dorsal markings. The anal appendages are vestigial and the vulvar scales are short.