Risa, Becker, 1907

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2023, Phylogeny and Taxonomy of the Risa Genus-group (Diptera: Ephydridae), with Description of a New Genus from Australia, Records of the Australian Museum (Rec. Aust. Mus.) 75 (1), pp. 1-23 : 5

Key to genera of the Risa group

1 Costa long, extended to vein M; crossvein dm–cu present ( Fig. 8 ). Mouthparts moderately geniculate, length of labellum slightly more than half haustellum ( Figs 5 , 10 ); reclinate fronto-orbital seta well developed, subequal to lateral vertical seta ( Figs 3–4 , 20 ) ........................ Notorisa gen. nov.

—— Costa short, extended to vein R 4+5; crossvein dm–cu absent ( Fig. 9 ). Mouthparts distinctly geniculate, labellum equal to haustellum ( Figs 23–25 , 28 , 35, 37 , 40–41 ); reclinate frontoorbital seta reduced or lacking ( Figs 21–22 ) ......................................... ( Risa Becker )............. 2

2 Face with a medial carina, in lateral view carina rounded; scutellar disc lacking setulae; costal section III (between R 2+3 and R 4+5) bearing c. 10–35 setulae along anterior margin ...................... subgenus Achaetorisa Papp

—— Face usually with a conspicuous, medial carina, in lateral view carina pointed (carina inconspicuous in R. kotrbae ); scutellar disc bearing a few, scattered setulae; costal section III (between R 2+3 and R 4+5) bearing c. 70–80, densely spaced setulae ...........................subgenus Risa Becker

Figures

Figures 6–9. Photographs of Notorisa mcalpinei sp. nov. (6–8) and Risa longirostris Becker (9). (6) Head, thorax and abdomen, anterooblique view. (7) Head, lateral view. (8) Wing. (9) Wing. Scale bars = 0.5 mm.

Figures 2–5. Photographs of Notorisa mcalpinei sp. nov. (2) Habitus, dorso-oblique view. (3) Head and thorax, dorsal view. (4) Head, anterior view. (5) Head and thorax, lateral view. Scale bars = 0.5 mm.

Figures 10–15. Photographs of Notorisa mcalpinei sp. nov. (10–14) and Risa longirostris Becker (15). (10) Proboscis, lateral view. (11) Labrum, posterior view. (12) Cibarium, posterior view. (13) Terminal female abdominal segments, ventral view. (14) Ventral receptacle, lateral view. (15) Ventral receptacle, lateral view. Scale bars = 0.2 mm (10–11), = 0.1 mm (12–13), = 0.05 mm (14–15).

Figures 20–25. Line drawing of frons and associated setae, dorsal view. (20) Notorisa mcalpinei sp. nov. (21) Risa longirostris Becker. (22) R. asiatica Ozerov. (23–25) Line drawing of head, lateral view. (23) R. longirostris Becker. (24) R. brevicornis Papp. (25) R. longicornuta Papp.

Figures 26–33. Photographs of Risa longirostris Becker (26–27, 29–31, 33) and Risa brevirostris sp. nov. (28, 32). (26) Head, anterooblique view. (27) Same, anterior view. (28) Proboscis, lateral view. (29) Rostrum, anterior view (microscopic photograph). (30) Same, lateral view. (31) Labellum, posterior view. (32) Labellum, anterior view. (33) Terminal female abdominal segments, anterior view. Scale bars = 0.2 mm (26–27), = 0.1 mm (28–30, 33), = 0.05 mm (31–32).

Figures 34–37. Line drawing and photographs of Risa. (34) Terminal female abdominal segments of R. brevirostris sp. nov., anterior view. (35) Habitus of R. brevicornis (Papp), antero-oblique view. (36) Head of R. brevirostris sp. nov., lateral view. (37) Habitus of R. salsolae (Mathis & Zatwarnicki), antero-oblique view. Scale bars = 0.1 mm (34), = 0.2 mm (35, 37).

Figures 38–41. Photographs of Risa brevirostris sp. nov. (38–39) and R. longirostris Becker (40–41). (38) Head, anterior view. (39) Same, dorso-oblique view. (40) Habitus, lateral view. (41) Head, antero-oblique view. Scale bars = 0.1 mm (38–39), = 0.2 mm (40–41).