Opeatocerata nhamunda sp. nov.

(Figs 138–144)

Diagnosis. Anterior cercus with a proclinate dorsal projection in lateral view (Fig. 140) and descendant plate subrectangular in posterior view (Fig. 142); posterior cercus with rounded apex in lateral view (Fig. 140); phallus subcylindrical (Fig. 144).

Description. Male (Fig. 138). Head: Face parallel-sided, dark brown with gray pruinescence visible in ventral view, about 5X longer than lower width. Ocellar tubercle protuberant, dark brown with gray pruinescence; ocelli brown. Antenna brown with black bristles; postpedicel about 2X longer than pedicel; stylus about 2.5X longer than postpedicel. Proboscis yellow, shorter than head height. Thorax yellow, shiny (Fig. 138). Legs yellow, except for hind femur and tibia with brown apical ring and all tarsomeres 4–5 black; hind tibia with anterodorsal and posterodorsal and anteroventral rows of longer bristles; hind tarsus with anterodorsal and posterodorsal rows of longer bristles. Wing (Fig. 139) hyaline, pterostigma, brown, conspicuous, about 2.4X longer than wide. Halter yellow. Abdomen yellow, shiny (Fig. 138); tergite 8 divided in two subrectangular plates; sternite 8 divided in two trapezoidal plates. Terminalia: Anterior cercus with a proclinate dorsal projection in lateral view (Fig. 140), with posterior margin slightly concave in dorsal view (Fig. 141); descendant plate subrectangular in posterior view (Fig. 142). Posterior cercus with rounded apex in lateral view (Fig. 140), with pointed dorsal subbasal process in dorsal view (Fig. 141). Hypoproct subrounded in lateral view (Fig. 140) and comma-shaped in posterior view (Fig. 142). Epandrial ventral lobe slightly bilobate at apex (Fig. 140), spiniform bristles mesially on dorsal lobe and longer bristles apically on ventral lobe (Fig. 140). Hypandrium longer than wide, with rounded apex, without long bristles. Phallus subcylindrical, longer than hypandrium (Fig. 144). Subepandrial sclerite wider than long, U-shaped (Fig. 143). Bacilliform sclerite folded and longer than subepandrial sclerite (Fig.143). Specimen length: 2.6 mm; wing length: 3.2 mm. Female. Unknown.

Geographical distribution. Brazil (Pará) (Fig. 211).

Type material. HOLOTYPE ♂, labelled: Brasil, Pará, Rio Nhamundá, 01º37’11”S – 57º37’34”W 25 m; 17–20.v.2008. J.A. Rafael e equipe. Malaise (INPA).

Holotype condition. Good; right wing mounted on microslide; abdomen in microtube with glycerin.

Etymology. The specific epithet is a noun in apposition and refers to the Nhamundá River, the locality where the specimen was collected.

Remarks. Opeatocerata nhamunda sp. nov. is similar to O. lopesi, by the anterior cercus with subrectangular descendant plate (Figs 105, 142), posterior cercus with rounded apex (Figs 103, 140) and dorsal subbasal pointed projection (Figs 104, 141), and epandrial lobe bilobate (Figs 103, 140). Differs from the latter by the posterior cercus without submedian projection (Fig. 141), phallus without dorsal appendix and spiniform projections (Fig. 144) and hypandrium with rounded apex. Opeatocerata lopesi has the posterior cercus with a submedian subtriangular projection (Fig. 104), phallus with dorsal subapical narrow appendix (Fig. 107) and spiniform projection, conspicuous ventrally (Fig. 108), and hypandrium with V-shaped apex (Fig. 108).