Hercostomus, Loew, 1857

Grichanov, Igor Ya., 2020, New species of Hercostomus Loew, 1857 from Afrotropics (Diptera: Dolichopodidae) and key to Afrotropical fauna, European Journal of Taxonomy 722, pp. 16-36 : 32-34

Key to Afrotropical species of Hercostomus (males)

1. R4+5 and M1+2 inconspicuously or slightly convergent; fore tarsomere 3 neither flattened nor widened; fore tarsomeres 4–5 simple ............................................................................................... 2

– R4+5 and M1+2 distinctly convergent; fore tarsomere 3 compressed and widened, rarely simple; if fore tarsomere 3 simple, then fore tarsomeres 4–5 flattened and widened ....................................... 4

2. Lower postocular setae black; cercus regularly subtriangular, black ( Grichanov 2004: fig. 24); body 2.3–2.6 mm [ Republic of the Congo, Equatorial Guinea] ............... H. intercedens Grichanov, 2004

– Lower postocular setae white; cercus elongate, narrow, with basoventral lobe yellow ( Fig. 1A ; Grichanov 1999: fig. 19) ................................................................................................................... 3

3. Mid and hind femora each with ventral row of erect cilia, about as long as diameter of femur ( Fig. 1 С); body 3.6 mm [ Namibia] .......................................................... H. brandbergensis sp. nov.

– Mid and hind femora without long ventral cilia; body 3.0– 4.5 mm [ Cameroon, DR Congo, South Africa, Tanzania, Uganda] ............................................................... H. nectarophagus Curran, 1924

4. Fore tarsomere 3 simple, fore tarsomeres 4–5 flattened and widened, fore tarsomere 4 white and fore tarsomere 5 deep black ( Fig. 2 С); body 2.4 mm [ Tanzania] ............................ H. fedotovae sp. nov.

– Fore tarsomere 3 compressed and widened, fore tarsomere 4 usually black and fore tarsomere 5 usually white ..................................................................................................................................... 5

5. Fore tarsomere 2 as long as fore tibia; fore tarsomere 3 equal to tarsomere 5 ( Grichanov 2004: fig. 22); body 4.3 mm [ Tanzania] ........................................................ H. heinrichi Grichanov, 2004

– Fore tarsomere 2 much shorter than fore tibia; fore tarsomere 3 usually not equal to tarsomere 5 ... ........................................................................................................................................................... 6

6. Fore tarsomeres 3–4 shortened; tarsomere 3 not longer than tarsomere 5; cercus with large basolateral lobe bearing several short setae; cercus with long narrow apex bearing several long setae ............ 7

– Fore tarsomeres 4–5 shortened; tarsomere 3 longer than tarsomere 5; cercus various, rarely with drawn-out apex ............................................................................................................................... 10

7. Fore tarsomere 4 with short dorsal lobe; tarsomere 3 nearly equal to tarsomere 5 ( Grichanov 1999: fig. 39); body 5.0 mm [ Tanzania, Zimbabwe] .................................... H. patellitarsis (Parent, 1934)

– Fore tarsomere 4 without lobe; tarsomere 5 at least twice longer than tarsomere 3 ......................... 8

8. Fore tibia mostly brown, white and swollen in distal ¼; fore tarsomere 2 white ( Grichanov 2004: fig. 18); body 5.1 mm [ Tanzania] .............................................................. H. freidbergi Grichanov, 2004

– Fore tibia yellow; fore tarsomere 2 mostly black [ Tanzania] ........................................................... 9

9. Fore tarsomere 2 with row of hooked cilia; tarsomere 5 3 times longer than tarsomere 3 ( Grichanov 1999: fig. 40); body 3.8 mm ................................................................. H. enghoffi Grichanov, 1999

– Fore tarsomere 2 with simple setulae; tarsomere 5 2 times longer than tarsomere 3 ( Grichanov 1999: fig. 41); body 3.7 mm ..................................................................... H. selikhovkini Grichanov, 1999

10. Cercus with long basolateral lobe, longer than cercus ( Figs 3F , 4F ) [ South Africa] .......................11

– Cercus with short basolateral lobe, shorter than cercus .................................................................. 12

11. Male face 2.7 times as high as wide in middle; fore tarsomere 3 strongly widened, 2 times longer than wide ( Fig. 3C ); body 4.9–5.5 mm ............................................................... H. sanipass sp. nov.

– Male face 4.9 times as high as wide in middle; fore tarsomere 3 weakly widened, at least 4 times longer than wide ( Fig. 4C ); body 3.6–4.1 mm ............................................... H. koshelevae sp. nov.

12. Cercus with large mushroom-like process bearing fan of at least 5 long strong setae; setae at least as long as cercus .................................................................................................................................. 13

– Cercus with short narrow process or low prominence at base, bearing at most 3 strong setae ...... 18

13. Anal lobe of wing with broad and deep postero-proximal emargination (e.g., Fig. 5A ; Grichanov 2004: fig. 15) ................................................................................................................................... 14

– Posterior wing margin evenly convex ............................................................................................ 16

14. Postpedicel 2.5–3 times longer than high; fore tarsomeres 4–5 with mostly black accumbent setulae; body 3.4–3.5 mm [ Ethiopia] ............................................................... H. kefaensis Grichanov, 2004

– Postpedicel slightly longer than high .............................................................................................. 15

15. Fore tarsomeres 4 and 5 dark, with fringe of white erect hairs, 1.5–2 times longer than diameter of tarsomeres ( Grichanov 2004: fig. 14); body 3.6 mm [ Ethiopia] ........... H. balensis Grichanov, 2004

– Fore tarsomere 4 with strong basodorsal black spine formed of 3 mostly fused bristles, with brush of white erect hairs; fore tarsomere 5 clear white, with dorsal fringe of white erect hairs, not longer than diameter of tarsomere ( Fig. 5 C ); body 4.9 mm [ Kenya] ............................ H. vikhrevi sp. nov.

16. Fore tarsomere 3 ¼ or 2 ⁄ 5 length of tarsomere 2 ( Grichanov 1999: Fig. 42); cercus with only several long cilia in distal part; basolateral process of cercus comparatively small, ¼ length of cercus, with 5–6 long setae ( Grichanov 1999: fig. 13); body 4.3 mm [ Kenya] ...... H. yakovlevi Grichanov, 1999

– Fore tarsomere 3 3 ⁄ 5 – ¾ length of tarsomere 2; cercus densely covered with long hairs in distal part; basolateral process of cercus large, with at least 10 long setae ...................................................... 17

17. Fore tarsomere 3 strongly widened, about 3 times longer than wide ( Grichanov 1999: fig. 44); basolateral process of cercus with about 20 long setae ( Grichanov 1999: fig. 12); body 4.6 mm [ Yemen] ...................................................................................................... H. scotti Grichanov, 1999

– Fore tarsomere 3 weakly widened, at least 4 times longer than wide ( Grichanov 1999: fig. 46); basolateral process of cercus with about 10 long setae ( Grichanov 1999: fig. 11); body 3.5–4.1 mm [ Ethiopia, Kenya, Uganda] ..................................................................... H. ozerovi Grichanov, 1999

18. Cercus with 2 lateroventral processes; fore tarsomere 3 strongly widened; segment 7 of abdomen at least ¼ longer than epandrium ........................................................................................................ 19

– Cercus with one basolateral prominence; fore tarsomere 3 usually weakly widened; segment 7 of abdomen equal to or shorter than epandrium ................................................................................. 20

19. Fore tarsomere 3 nearly equal in length to tarsomere 2 ( Grichanov 1999: fig. 45); distoventral process of cercus narrow, as wide as basoventral process ( Grichanov 2011b: fig. 72); body 3.0 mm [ South Africa] ...................................................................................................... H. perturbus Curran, 1924

– Fore tarsomere 3 approximately half as long as tarsomere 2 ( Grichanov 1999: fig. 48); mid-ventral process of cercus wide, 2 times wider than basoventral process ( Grichanov 1999: fig. 15); body 3.5 mm [ DR Congo, Kenya, Tanzania] ..................................................... H. wittei Grichanov, 1999

20. Fore tarsomere 3 half as long as tarsomere 2 or shorter; fore tarsomere 1 shorter than tarsomere 2; epandrium slightly projected apicoventrally; cercus with long and narrow distal part .................. 21

– Fore tarsomere 3 ¾ length of tarsomere 2; fore tarsomere 1 longer than tarsomere 2; epandrium strongly projected apicoventrally; cercus relatively broad ............................................................. 22

21. Fore tarsomere 2 slightly longer than tarsomere 1 and 2 times longer than tarsomere 3 ( Grichanov 1999: fig. 43); mid tibia without ventral seta; body 4.6 mm [ Cameroon] .......................................... .................................................................................................................. H. tobiasi Grichanov, 1999

– Fore tarsomere 2: 2 times longer than tarsomere 1 and 4 times longer than tarsomere 3 ( Grichanov 2004: fig. 30); mid tibia with ventral seta at ¾; body 4.5 mm [ Tanzania] .......................................... .................................................................................................................... H. ngozi Grichanov, 2004

22. Cercus truncated at apex, with distinct basolateral prominence bearing 2–3 strong setae ( Grichanov 1999: fig. 17); body 3.4 mm [ Uganda] ............................................. H. mostovskii Grichanov, 1999

– Cercus somewhat projected apicoventrally, with dorsal subapical tubercle and indistinct basolateral prominence ( Grichanov 1999: fig. 16); body 3.4 mm [ Cameroon, Uganda] .......................................................................................... H. krivosheinae Grichanov, 1999

Figures

Fig. 1. Hercostomus brandbergensis sp. nov., ♂, paratype (NMNW). A. Habitus. B. Antenna. C. Mid femora, anterior view. D. Hypopygium, right lateral view. E. Distoventral appendages of epandrium. F. Cercus, surstylus and distal lobe of postgonite.

Fig. 2. Hercostomus fedotovae sp. nov., ♂, holotype (ZMUM). A. Habitus. B. Antenna. C. Fore tarsus. D. Distal appendages of epandrium. E. Hypopygium, left lateral view. F. Hypopygium, right lateral view.

Fig. 3. Hercostomus sanipass sp. nov., ♂, paratype, no date (NMSA). A. Habitus. B. Antenna. C. Fore tibia and tarsus. D. Hypopygium, right lateral view. E. Distoventral appendages of epandrium. F. Cercus.

Fig. 4. Hercostomus koshelevae sp. nov., ♂, holotype (MNSA; A–C); ♂, paratype, Town Bush (MNSA; D–F). A. Habitus. B. Antenna. C. Fore tarsus. D. Hypopygium, right lateral view. E. Distoventral appendages of epandrium. F. Cercus.

Fig. 5. Hercostomus vikhrevi sp. nov., ♂, holotype (ZMUM). A. Habitus. B. Antenna. C. Fore tarsus. D. Hypopygium, right lateral view. E. Distoventral appendages of epandrium. F. Cercus.