Systenus, Loew, 1857

Ramos-Pastrana, Yardany, Merchan-Vargas, Geraldine Lucia & Soares, Matheus M. M., 2024, First record of the genus Systenus Loew (Diptera: Dolichopodidae) from Colombia, with description of four new species, Zootaxa 5514 (3), pp. 257-272 : 258-259

Key to species of Systenus from Colombia (males)

1 Metepimeron dark (e.g. Figs 1A, 2A); abdominal tergites 1–3 mostly metallic green (e.g. Figs 1E, 2E).................. 3

- Metepimeron yellow ( Figs 5C, 6A); abdominal tergites 1–3 partly yellow ( Figs 5C, 6A)............................. 2

2 Femur III entirely yellow ( Fig. 5C); abdominal tergite 3 dorsally metallic green, tergites 4–5 wholly metallic green ( Fig. 5C); surstylus slightly curved ventrally at apex ( Fig. 5D)............................................ S. flaviatus Naglis

- Femur III yellow with dark brown apex ( Fig. 6A); abdominal tergite 3 mostly yellow ( Fig. 6A), with T-shaped macula dorsally, tergites 4–5 dark brown; surstylus abruptly curved ventrally at apex ( Fig. 6B)..................... S. naranjensis Bickel

3 Antenna wholly dark brown ( Fig. 3A, B); femora mostly dark brown ( Fig. 3A)....................... S. fuscus sp. nov.

- Antenna partly orangish yellow ( Figs 1B, 2B, 4B); femora yellow ( Figs 2A, 4A)................................... 4

4 It 3 white ( Fig. 5E); wing apex brown: posterior wing membrane reduced near apex, with vein M 1 ending on posterior margin ( Fig. 5E)........................................................................... S. maculipennis Bickel

- It 3 yellow ( Figs 2A, 4A); wing apex unmodified, membrane hyaline or brownish ( Figs 1D, 2D)....................... 5

5 Postpedicel wholly orangish yellow at basal 1/2 ( Fig. 6C); abdominal segment 7 forming peduncle shorter than epandrial capsule ( Fig. 6C); cercus rectangular, shorter than epandrial capsule ( Fig. 6D)......................... S. parkeri Bickel

- Postpedicel partly brownish at basal 1/2 ( Figs 1B, 2B, 4B); abdominal segment 7 forming peduncle longer than epandrial capsule ( Figs 1A, 2A, 4A); cercus digitiform, as long or longer than epandrial capsule ( Figs 1F, 2F, 4F)................. 6

6 Palpus mostly brown ( Fig. 1B); wing membrane light brown ( Fig. 1D); cercus about 2X longer than epandrial capsule ( Fig. 1F).................................................................................... S. bickeli sp. nov.

- Palpus yellow ( Fig. 2B); wing membrane hyaline ( Fig. 2D); cercus as long or only slightly longer than epandrial capsule ( Figs 2F, 4F)......................................................................................... 7

7 Surstylus longer than cercus and epandrial capsule, ventral edge nearly straight, only slightly narrowed and curved ventrally at apex ( Fig. 5B)............................................................................ S. beatae Naglis

- Surstylus shorter or as long as cercus and epandrial capsule and abruptly narrowed towards apex ( Figs 2F, 4F)........... 8

8 Coxa III mostly yellow ( Fig. 4A); surstylus as long as cercus, wide, abruptly narrowed at apex, with 1 basodorsal acute process ( Fig. 4F, G)............................................................................ S. grossus sp. nov.

- Coxa III mostly brown ( Fig. 2A); surstylus shorter than cercus, narrow, slightly narrowed at apex, with 1 basodorsal acute process and 1 apicoventral acute process ( Fig. 2F)......................................... S. colombiensis sp. nov.