Setostylus, Matile, 1990

Qi, Lei, Huang, Junhao, Wu, Hong & Wang, Qingyun, 2022, Two new species of Setostylus Matile, 1990 (Diptera: Keroplatidae) from China, Zootaxa 5165 (3), pp. 443-450 : 448-449

Key to the species of Setostylus (based on male adults)

1. Two ocelli.......................................................................................... 2

- Three ocelli......................................................................................... 3

2. Flagellomere 14 with an antennal apicule; gonocoxites with anterior margin not emarginated ( Matile 1990: Fig. 919)............................................................................... S. singularis (Lane) [Neotropical]

- Flagellomere 14 without an antennal apicule; gonocoxites with anterior margin distinctly emarginated ( Matile 1990: Fig. 922)............................................................................ S. bifidus Matile [Neotropical]

3. Wing without pattern.................................................................................. 4

- Wing with distinct patterns............................................................................. 9

4. Scutellum without bristles.............................................................................. 5

- Scutellum covered with bristles.......................................................................... 6

5. Tergite 9 longer than wide ( Matile 1990: Fig. 936); tarsus I 1.5 times longer than the tibia. S. rufobrunneus Matile [Oriental]

- Tergite 9 wider than long ( Matile 1990: Fig. 937); tarsus I 2.5 times longer than the tibia..... S. bispinosus Matile [Oriental]

6. Scutum with pattern................................................................................... 7

- Scutum without pattern; flagellomere 14 cordiform apically ( Papp et al. 2006)................ S. alienus Papp [Oriental]

7. Scutum with two stripes............................................................................... 8

- Scutum with three stripes; tergite 9 subpentagonal ( Fig. 2 ).............................. S. tridigitus sp. n. [Oriental]

8. Scape and pedicel dark brown; palpus brown; tergites 2–4 somewhat transparent ( Fig. 4 )...... S. triumphus sp. n [Oriental]

- Scape and pedicel reddish brown; palpus reddish brown; tergites 2–4 with a large yellow basal spot on both sides ( Matile 1990)......................................................................... S. stubbsi Matile [Oriental]

9. Posterior margin of tergite 9 emarginated................................................................. 10

- Posterior margin of tergite 9 rounded.................................................................... 11

10. R+M fusion longer than the stem of median fork; gonostylus dorsomedially with a small, semi-transparent, posterodorsallyprojecting tooth ( Huerta & Fitzgerald, 2020: Figs 2 , 3D )........................ S. xoxo Huerta & Fitzgerald [Nearctic]

- R+M fusion equal to half the stem of median fork; gonostylus dorsomedially without tooth ( Matile 1990: Fig. 921)................................................................................ S. pictipennis Matile [Neotropical]

11. Goncoxites with posterior margin emarginated............................................................. 12

- Goncoxites with posterior margin not emarginated, with two submedian tubercles ( Ševčík et al. 2021: Fig. 14A)..................................................................... S. fangshuoi Ševčík, Hippa & Burdíková [Oriental]

12. Wing with light brown fumose along costal edge near apex ( Huerta & Fitzgerald, 2020)..................................................................................................... S. bellulus (Williston) [Neotropical]

- Wing with light brown fumose along costal edge near anterior apical portion of wing to distinctly marked with brown more broadly............................................................................................ 13

13. Palpus yellow....................................................................................... 14

- Palpus reddish brown; halteres with yellowish stem and black knob ( Edwards 1931)...... S. innotatus (Edwards) [Oriental]

14. Costa reaching slightly beyond one-third distance from vein R 4+5 to M 1;gonostylus with a minute projection on dorsoapical part, arcuate projection ventrally ( Sasakawa & Tamu 1961: Figs 1–2 ).......... S. abdominalis (Sasakawa & Tamu) [Palaearctic]

- Costa reaching almost midway between R 4+5 to M 1; gonostylus without projection ( Xu et al. 2007: Figs 5 –6).......................................................................... S. chinensis Cao, Evenhuis & Zhou [Palaearctic]

Figures

FIGURE 1. Setostylus tridigitus sp. n., holotype, male, lateral view.

FIGURE 2. Setostylus tridigitus sp. n., holotype. a. head (frontal view), antennae removed; b. wing; c. antenna; d–e. thorax (d. lateral view; e. dorsal view); f–h. terminalia (f. vertral view, with a close-up of gonostylus in the upper right; g. dorsal view; h. lateral view). Slide No. DHS-8-85.

FIGURE 3. Setostylus triumphus sp. n., holotype, mlae, lateral view.

FIGURE 4. Setostylus triumphus sp. n., holotype. a. head (frontal view), antennae removed; b. wing; c. antenna; d–e. thorax (d. lateral view; e. dorsal view); f–h. terminalia (f. vertral view, with a close-up of gonostylus in the upper right; g. dorsal view; h. lateral view). Slide No. LWS-5-59.

FIGURE 5. Neighbor-joining (NJ) tree of the genus Setostylus (Matile) based on mitochondrial gene maker (COI) with Kimura 2-parameter (K2P) model.