Podonomus

Siri, Augusto & Donato, Mariano, 2012, Two new species of Podonomus (Diptera: Chironomidae: Podonominae) of the Brundin’s decarthrus group from Ventania system, Argentina, Zootaxa 3548, pp. 39-54 : 51-52

Key for the South American Podonomus pupae of the Brundin’s decarthrus group. Adapted from the Podonomus Brundin’s key (1966). Only valid species are included.

1 Anal lobe with 5 lateral wavy setae....................................................................... 2

- Anal lobe with 6 or more lateral wavy setae................................................................. 3

2 Respiratory atrium of TH oval and robust; plastron plate with more or less parallel sides ( Fig. 30 ); abdominal segments III–VIII with mid anterior dark marking with 2–4 rows of very short spines fused by its bases ( Fig. 33 )................................................................................................... P. quinquesetosus sp. n.

- Respiratory atrium of TH with more or less parallel sides, plastron plate subtriangular; abdominal segments without anterior marking ( Figs 9 , 11 Roque & Trivinho-Strixino 2004)............................ P. pepinelli Roque et Trivinho-Strixino

3 Plastron plate of TH dome shaped and circular; length of plastron plate / total length of TH higher than 0.75............. 4

- Plastron plate of TH not dome shaped; if it circular, length of plastron plate / total length of TH lower than 0.50........... 5

4 Plastron plate with tubercles and ridges, without supporting structure............................... P. fittkaui Brundin

- Plastron plate without tubercles or ridges, but with supporting structure in lower wall of the plastron plate................................................................................................... P. orbiculatus Brundin

5 Plastron plate large, longer than stalk...................................................................... 6

- Plastron plate small, shorter than stalk.................................................................... 14

6 Segment VIII narrower than segment VII................................................................... 7

- Segment VIII as wide as segment VII..................................................................... 13

7 Dorsal setae in the mid section of segments III–VII surrounded by group of strong tubercles ( Figs 13, 14 )............... 8

- Dorsal setae in the mid section of segments III–VII not surrounded by group of strong tubercles ( Figs 32, 34 ), weakly devel- oped if tubercles present................................................................................ 9

8 Atrium of TH more or less parallel sided, slightly narrowed apically; furrow with aeropyles short ( Brundin 1966, Fig. 238).......................................................................................... P. besti Brundin

- Atrium of TH widened near apex; furrow with aeropyles long.................................... P. tehuelche sp. n.

9 Distal portion of the respiratory atrium surrounded by large, well delimited marked field............. P. rivulorum Brundin

- Distal portion of respiratory atrium not surrounded by marked field............................................. 10

10 Stalk of horn covered with very regular, wide polygonal meshes prolonged into short spines distally................... 11

- Stalk of horn covered with very irregular longish meshes distally prolonged into slender spines....................... 12

11 Furrow with aeropyles at distal end of the respiratory atrium shorter than apex of atrium............. P. bipartitus Brundin

- Furrow with aeropyles at distal end of respiratory atrium longer than apex of the atrium............... P. c h i le n s i s Brundin

12 Plastron plate longer than broad....................................................... P. magellanicus Brundin

- Plastron plate about as long as broad.......................................................... P. illesi Brundin

13 Plastron plate of horn of moderate size, comparatively narrow, stalk well developed, about half as long as plate................................................................................................ P. radonichi Brundin

- Plastron plate large, much wider than strongly reduced stalk, stalk about one tenth as long as the plate...................................................................................................... P. decarthrus Edwards

14 Plastron plate round, with deep incisures basally; pores arranged in radial pattern................... P. montanus Brundin

- Plastron plate somewhat broader than long, without incisures; pores arranged in polygonal groups.... P. oreophilus Brundin

Figures

FIGURES 29 – 35. Podonomus quinquesetosus sp. n. Pupa: 29, frontal apotome; 30, thoracic horn, draw and photograph; 31, cephalothoracic setation; 32, entire abdomen, dorsal view; 33, detail of spines in the anterior region of abdominal segment IV; 34, abdominal setation of segment IV: dorsal (up), ventral (down); 35, segments VII – VIII and anal lobe, draw and photograph. Scale bars = 100 μm, except for Figs 31, 32 = 200 μm.

FIGURES 7 – 9. Podonomus tehuelche sp. n. Female: 7, antenna; 8, wing; 9, genitalia: a—ventral view, draw and photograph, b—dorsal view, c—lateral view, draw and photograph. Scale bars = 100 μm.

FIGURES 10 – 15. Podonomus tehuelche sp. n. Pupa: 10, frontal apotome; 11, thoracic horn: a—draw and photograph, b—furrow of plastron plate with aeropyles (arrow indicating the aeropyles); 12, cephalothoracic setation; 13, entire abdomen, dorsal view; 14, abdominal setation of segment IV: dorsal (up), ventral (down); 15, segments VII – VIII and anal lobe. Scale bars: Figs 10, 11, 14, 15 = 100 μm; 12, 13 = 200 μm.