About Paracercion melanotum (Selys, 1876)
Paracercion melanotum is a medium-sized damselfly. Males of this species have deep blue eyes. Their thorax is black on the dorsal side, with very broad azure blue antehumeral stripes; in the related species Paracercion calamorum, these stripes are very narrow or missing entirely. The lateral sides of the thorax are blue, with a fine black line on the upper part of each lateral suture. Unlike P. calamorum, Paracercion melanotum has no pruinescence. Its wings are transparent, and the pterostigma is yellow, framed by thick black nervures. Its abdomen is azure blue, with broad black dorsal marks extending up to segment 7. Segment 2 has a distinct broad dorsal spot shaped like a thistle-head, connected narrowly to a fine apical ring. This marking can be used to distinguish Paracercion melanotum from species in the genus Pseudagrion. Segment 10 has a narrow mid-dorsal black streak. Females have dull green coloration. Their abdomen follows the same pattern as the male abdomen, but the lateral ground colour is yellowish red. Segments 8 and 9 are broadly black on the dorsum, and only the apical border of segment 10 is blue. This damselfly breeds in shallow lakes, ponds, and paddy fields in lowland areas, and perches on floating vegetation.
