Idiocnemis chloropleura

Male : Idiocnemis chloropleura is a relatively large member of the inornata-group. It is distinguished by its very prominent pronotal tubercles and strongly upcurved inferior anal appendages, a combination unique among closely related species. The head bears distinct postocellar spots, while the superior appendages are incurved apically and equipped with a small inner hook on the distal third. The ligula possesses narrow terminal lobes and a characteristic distal median cleft. The wings have 15–18 postnodal crossveins in the forewing and 11–16 in the hindwing, with the arculus positioned at or distal to Ax2. These structural characters readily separate the species from I. strumidens, I. fissidens, and other northern New Guinea representatives of the inornata-group. Female : The female resembles the male but is generally paler in coloration. The pronotal tubercles are not enlarged, although the pronotal fossae are marked with a pair of black spots. The posterior pronotal lobe is bow-shaped, only slightly elevated, and the antehumeral stripe is reduced to a characteristic exclamation-mark shape. The synthoracic markings are less distinct than in the male, while the pterostigma is rhombic and the arculus lies distal to Ax2. The valvae extend only slightly beyond the posterior margin of abdominal segment 10. The shape of the pronotum provides one of the most reliable characters for identifying females of this species.