aorsa -group

The name of this group is maintained from the original classification by Stichel (1902). Opoptera staudingeri, O. aorsa, O. hilaris, O. arsippe and O. bracteolata form a monophyletic group supported by three unambiguous character changes (Fig. 3 C): in dorsal view, anterior edge of tegumen markedly concave (character 19:1, Fig. 5 F); presence of projected ‘flaps’ on lateral edges of sterigma (35:1, Fig. 6 D–F); intersegmental sac between seventh abdominal sternite and sterigma with two lateral pockets (37:1, Fig. 6 F). Although I was unable to borrow females of O. arsippe and O. bracteolata for examination, based on the above distribution of character changes I predict that characters 35:1 (or variation thereof) and 37:1 will also be found in these species.

The grouping of O. aorsa, O. hilaris, O. arsippe and O. bracteolata is supported by two unambiguous character changes (Fig. 3 C): presence of a HW tail at vein M3 (character 9:1; Fig. 1 E); Lateral uncus wings expanded laterally to form two dorsolateral keels (28:2, Fig. 5 D, H). Furthermore, these four species have an angular FW apex due to a small depression of the wing membrane at vein M3 (character 2:2; Fig. 1 D).

Two other character changes are also of interest within this group. Opoptera bracteolata is the only member of the aorsa -group in which the males possess a thin hairpencil inside the HW discal cell (12:1, a secondary gain). Opoptera arsippe is the only species in the genus in which the scent organ at HW vein Cu2 constitutes a shallow depression (15:1, Fig. 1 L) and not a ‘scent-pocket’ (15:2, Fig. 1 K; see Discussion).