Chvalaea Papp & Földvári

Ale-Rocha, R., 2006, First description of species of Chvalaea Papp & Földvári from the Neotropical Region (Diptera, Hybotidae, Ocydromiinae), Zootaxa 1167, pp. 17-30 : 18-19

Chvalaea Papp & Földvári

Diagnosis

Antennae inserted above the middle of head; basal flagellomere long with a bristlelike terminal bare arista. Frons short. Eyes distinctly separated on frons and meeting below antennae in both sexes. Pterostigma on costal cell; anal lobe reduced; cell dm emitting two veins. Tarsomeres with short robust black protuberances on ventral surface; pulvilli lacking. Abdominal sclerites heavily sclerotized and punctate. Male sclerites of eighth abdominal segment fused, forming a broad ring as long as preceding segment, with small circular membranous area on ventral surface. Male terminalia hidden in eighth segment; cerci broad. Female cerci hidden in eighth segment.

Male terminalia description. Small, rotated approximately 90 0 to right, asymmetrical and retracted in eighth abdominal segment ( Figs. 5, 6). Epandrium deeply cleft dorsally; epandrial lamellae united dorsally by narrow sclerotized basal connection ( Figs. 9, 24, 28), occasionally this region indistinct, membranous ( Fig. 13). Surstyli articulated, elongate, cylindrical, ventro­dorsally directed. Hypandrium elongate, rather symmetrical, with distal margin slightly convex ( Figs. 8, 14, 21, 27); dorsal bridge sclerotized. Bacilliform sclerites elongate, bearing setae; subepandrial sclerite broadly articulated with dorsal bridge. Phallus elongate, biarticulated, bent inside of hypopygium; phallic shaft gradually arched, cylindrical; distiphallus expanded basally, with simple ribbon­like, long terminal appendage ( Fig. 15); basiphallus­distiphallus articulation projected outside of epandrium, visible on left side of cerci ( Figs. 7, 12, 23, 29); ejaculatory apodeme fused to base of phallus ( Fig. 15). Cercus broad. Hypoproct broad and articulated with subepandrial sclerite ( Figs. 9, 13, 24, 28).

Remarks

Chvalaea belongs to the Ocydromiini on the basis of a short cell cu p with truncate apex, short proboscis directed downwards, terminalia asymmetrical rotated through 90º, epandrium with a pair of articulated surstyli, phallus biarticulated, ventral apodeme and postgonites lacking. The presence of a biarticulated phallus plus the lost of postgonites and a ventral apodeme are synapomorphies of the tribe Ocydromiini as defined by Sinclair & Cumming (2000). The Ocydromiini is a cosmopolitan tribe, and is the only tribe of Ocydromiinae present in the Neotropical Region.

On the basis of the antennae placed above middle of head, face long, eyes contiguous on the face, frons short with dichoptic eyes, Rs long and anal lobe undeveloped, Chvalaea appears related to Oropezella Collin. However , the hypandrium is similar to that of Ocydromia ( Chvála 1983, fig. 519), and the long distiphallus in ribbon form is similar to Leptopeza ( Chvála 1983, fig. 533), Hoplopeza ( Rafael 1995, fig 9) and Leptodromiella ( Chvála 1983, fig. 546). The terminalia hidden or retracted within the eighth segment, as well as the hypoproct in the form of a broad plate appear to be apomorphic characters of Chvalaea .

Geographical distribution

Neotropical ( Brazil, Peru, Costa Rica, Guatemala, Bolivia, Ecuador, Chile), Oriental, Palearctic and Australasian Regions (modified from Sinclair & Cumming 2000).