Palaiargia optata

Male : Palaiargia optata is a medium-sized blue-and-black species lacking pale postocular spots. The head bears a broad pale transverse band across the frons, while the synthorax is predominantly black with complete blue antehumeral stripes and broad lateral blue markings. The abdomen is long and slender, mostly black with well-developed blue markings on the basal and posterior segments. The male is readily distinguished by its characteristic anal appendages, in which the ventral portion of the tenth abdominal segment is shortened and the stout inferior appendages are inserted well posteriorly, giving the terminal appendages a distinctive appearance. Female : The female closely resembles the male in colour pattern, differing only in minor details. The labrum is largely green, bordered by a black line, while the frons bears a pale green transverse band divided medially by a fine black line. The synthorax has complete light green antehumeral stripes and broad lateral markings, with an additional small blue-green spot below the first lateral suture. The abdomen is deep black with light blue markings, including paired blue spots on segment 8 and a continuous blue dorsal stripe on segment 9. The anal appendages are short, triangular, and slightly flattened, while the genital valves are black with bright yellow on the apical two-thirds.