Rheotanytarsus Thienemann & Bause, 1913

Dantas, Galileu P. S., Huamantinco Araujo, Ana A. & Hamada, Neusa, 2020, A new species of Rheotanytarsus Thienemann & Bause (Diptera: Chironomidae) from Peruvian Andes, with updated key to South American species, Zootaxa 4722 (2), pp. 195-200 : 198-199

Key to males of South American Rheotanytarsus Thienemann & Bause species

(adapted from Andersen & Kyerematen 2001)

1. Median volsella with apical setiform lamellae fused into a plate; wing length <2 mm ............................... 2

1’. Median volsella with apical setiform lamellae not fused into a plate; wing length> 2 mm ............................ 4

2. Median volsella with rounded apical plate.................................................................. 3

2´. Median volsella with distinct petal-like apical plate. ( Andersen & Kyerematen 2001, Figures 9–12)..................................................................................................... R. pelus (Roback, 1960)

3. Superior volsella somewhat oval, about the same size as median volsella; wing length about 1.75 mm. (Reiss 1972, Figure 12)............................................................................. R. lamellatus Reiss, 1972

3´. Superior volsella subtriangular, shorter than median volsella; wing length about 1.10 mm. ( Andersen & Kyerematen 2001, Figures 1 –8)................................................. R. pantanalensis Andersen & Kyerematen, 2001

4. Median volsella distinctly longer than superior volsella; gonostylus broadest basally, with abruptly tapered apical half. (Reiss 1972, Figure 11).................................................................... R. globosus Reiss, 1972

4´. Median volsella about the same size as the superior volsella; gonostylus broadest subbasally, evenly tapering toward apex. ( Figure 1 )............................................................................... R. amaru sp. n.

Figures

FIGURE 1. Rheotanytarsus amaru sp. n., Adult male:A. Head, in frontal view. B. Thorax, in lateral view. C. Wing. D. Hypopygium, in dorsal view. E. Hypopygium in dorsal view, with tergite IX removed.