Mesorhaga Schiner urn:lsid:zoobank.org:act: 2D4EF16C-BFCA-4126-A535-305FE0B46543

Mesorhaga Schiner, 1868: 217 .

Type species: Mesorhaga tristis Schiner, monotypy.

Aptorthus Aldrich, 1893: 48 .

Type species: Aptorthus albiciliatus Aldrich, 1893 (subsequent designation by Coquillett, 1910: 509). Synonymized by Aldrich (1900): 531.

Identification key to males of South American Mesorhaga

For notes on other Neotropical species and a key for Mesoamerican and Caribbean species, see Bickel (2007).

1 Femora mostly or entirely black.......................................................................... 2

- Femora yellow....................................................................................... 5

2 Wing vein M 1 with gentle curve (Naglis 2000, fig. 1b); fore and mid tibiae with rows of conspicuous setae (Naglis 2000, fig. 1a); cercus with three digitiform projections at apex (Naglis 2000, figs 1c–d) (Brazil: Amazonas)......... M. saetosa Naglis

- Wing vein M 1 distinctly curved, almost right angle bend (see Fig. 12); fore and mid tibiae without conspicuous rows of setae; cercus without remarkable projections (Fig. 16) or with apical notch (Bickel 2007, fig. 1f)........................... 3

3 Ventral occiput with long black setae; wing membrane hyaline; halter black; all legs entirely black (Venezuela).................................................................................................. M. tristis Schiner

- Ventral occiput with short whitish setae, wing membrane with dark brown cloud along anterior margin; halter black or yellow; apex of fore and mid femora, all tibiae and base of tarsi yellow................................................. 4

4 Cercus with some long, lateral setae near medial bend of appendage, apex with notch (Bickel 2007, fig. 1f) (Peru, Ecuador and Venezuela)............................................................................ M. funebris Parent

- Cercus without long, lateral setae at middle of appendage, apex homboid (Figs 15 and 16) (Brazil: Piauí)..................................................................................................... M. gomesi sp. nov.

5 Wing membrane with grayish cloud on apical fourth, between end of R 2+3 and M 1, wing vein M 1 distinct curved, almost right angle bend (Becker 1922, fig. 146) (Paraguay).................................................. M. laeta Becker

- Wing membrane hyaline, wing vein M 1 both distinctly (right angle) or gently curved................................ 6

6 Thorax with 2 pairs of acrostichal setae; surstylus much shorter than epandrial lobe (Naglis 2000, fig. 2b–c) (Brazil: Amazonas)............................................................................. M. aurata Naglis

- Thorax with 3 pairs of acrostichal setae; surstylus as long as epandrial lobe (Figs 7, 8, 23, 24, 31, 32)................... 7

7 Wing vein M 1 distinct curved, almost right angle bend (Fig. 4); apex of cercus not noticeably enlarged and covered by setae similar in length (Figs 22–24) (Brazil: Piauí)................................................ M. parnasete sp. nov.

- Wing vein M 1 gently bent towards apex (Figs 20, 28); apex of cercus noticeably enlarged, with 2–3 larger setae at apex (Figs 23, 24, 31, 32)........................................................................................ 8

8 Fore tarsomere 5 slightly expanded; apex of cercus with small subrectangular expansion (Brazil: Piauí).................................................................................................... M. danbickeli sp. nov.

- Fore tarsomere 5 as broad as preceding segments; apex of cercus triangular (Brazil: Piauí)............. M. laetitia sp. nov.