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

Key for the South American Podonomus male of the Brundin’s decarthrus group. Adapted from the Podonomus Brundin’s key (1966)

1. Eyes hairy........................................................................................... 2

- Eyes bare............................................................................................ 3

2. Gonostylus strongly flattened, broad disc-like; lacking subapical lobe; 6 spine-like setae close to the apical lobe................................................................................................ P. discistylus Wirth

- Gonostylus not flattened like broad disc; with short and rounded subapical lobe; without spine-like setae close to the apical lobe............................................................................. P. quinquesetosus sp. n.

3. “ t ” seta of subapical lobe of gonostylus present.............................................................. 4

- “ t ” seta of subapical lobe of gonostylus absent, but often 2 or 3 setae in the same position present..................... 6

4. “ t ” seta of subapical lobe very long and thin, longer than subapical lobe; apical lobe distinctly longer than subapical; “ p ” seta long and stout............................................................................ P. besti Brundin

- “ t ” seta of subapical lobe short, shorter than subapical lobe; length of apical lobe and “ p ” seta variable.................. 5

5. Apical and subapical lobes of gonostylus long and slender; “ t ” seta of subapical lobe basally situated; antenna reduced and female-like; wing reduced................................................................ P. c h i le n s i s Brundin

- Apical and subapical lobes of gonostylus short; “ t ” seta of subapical lobe situated apically; antenna not reduced and not female-like; wing not reduced.......................................................... P. valdesianus Brundin

6. Gonocoxite dorsobasally with high longitudinal ridge......................................................... 7

- Gonocoxite lacking longitudinal ridge..................................................................... 8

7. Gonostylus strongly flattened and squarish.............................................. P. magellanicus Brundin

- Gonostylus of normal type ............................................................. P. longispinus Brundin

8. Antennal plume reduced................................................................ P. radonichi Brundin

- Antennal plume not reduced............................................................................. 9

9. Subapical lobe of gonostylus long........................................................ P. bipartitus Brundin

- Subapical lobe of gonostylus short or reduced, spine-like..................................................... 10

10. Gonostylus with very long “ p ” seta reaching far beyond tip of apical lobe.......................... P. edwardsi Brundin

- Gonostylus with inconspicuous “ p ” seta, never reaching tip of apical lobe........................................ 11

11. Subapical lobe reduced, short triangular and spine-like....................................................... 12

- Subapical lobe short, rounded, never reduced triangular nor spine-like........................................... 14

12. Length of apical and subapical lobes subequal, subapical lobe very close to apical one ( Brundin 1966, Figs 198 and 200).. 13

- Subapical lobe smaller than apical, subapical lobe more or less separated from apical one ( Fig. 6 )........ P. tehuelche sp. n.

13. Inner margin of gonocoxite abruptly contracted on apical half, forming marked angle............... P. decarthrus Edwards

- Inner margin of gonocoxite contracted on apical half, forming smooth angle.......................... P. kuscheli Wirth

14. Subapical lobe very broad, more or less triangular, dorsally covered with microtrichia except its tip.... P. rivulorum Brundin

- Subapical lobe rounded at tip, as broad as apical lobe, never covered with microtrichia................................................................................... P. fittkaui Brundin , P. montanus Brundin , and P. illesi Brundin

Figures

FIGURES 2 – 6. Podonomus tehuelche sp. n. Male: 2, head; 3, antenna, 4, wing; 5, hypopygium, dorsal view, draw and photograph; 6, gonostylus. Scale bars = 100 μm, except for Fig. 6 = 20 μm.