Hercostomus baishanzuensis

Tang, Chufei, Zhang, Lili & Yang, Ding, 2014, New species of Hercostomus baishanzuensis group from Tibet (Diptera: Dolichopodidae, Dolichopodinae), Zootaxa 3881 (6), pp. 549-562 : 550-551

Key to species (males) of Hercostomus baishanzuensis group

(modified from Yang et al. 2011)

1 Acr present.......................................................................................... 2

– Acr absent.......................................................................................... 25

2 First flagellomere elongated, at least 2 times longer than wide................................................. 3

– First flagellomere not elongated, less than 2 times width..................................................... 9

3 Postocular bristles black............................................................................... 4

– Mid and lower postocular bristles pale yellow................................... H. caixiae Zhang, Yang et Grootaert

4 Basal segment of arista short, 0.3 times as long as apical portion of arista ( Yang et al 2011, fig. 434)............................................................................................... H. curvilobatus Yang et Saigusa

– Basal segment long, 0.5–1.0 times as long as apical portion of arista............................................ 5

5 Arista arising at middle of the first flagellomere............................................................ 6

– Arista arising near the base of the first flagellomere......................................................... 7

6 Phallus specialized, hazelnut-shaped at tip ( Fig. 21 )......................................... H. nuciformis sp. nov.

– Phallus not strongly modified ( Yang et al. 2011, fig. 431)............................ H. baishuihensis Yang et Saigusa

7 Fore tibia with 1 weak apical bristle......................................................... H. spatiosus Yang

– Fore tibia without apical bristle......................................................................... 8

8 Arista arising at basal third of first flagellomere; inner epandrial lobe small ( Yang et al. 2011, fig. 440).............................................................................................. H. jingxingensis Yang et Saigusa

– Arista arising at basal fourth of first flagellomere; inner epandrial lobe long and finger-shaped ( Yang et al. 2011, fig. 447).............................................................................. H. qinlingensis Yang et Saigusa

9 Coxae not all black................................................................................... 10

– Coxae all wholly black................................................................................ 13

10 Fore coxa brownish ( Fig. 9)........................................................... H. pailongensis sp. nov.

– Fore coxa yellow................................................................................... 11

11 Mid and hind coxae black............................................................... H. fanjingensis Wei

– Mid coxa blackish to black except at base, hind coxa yellow................................................. 12

12 Antenna dark yellow, first flagellomere black except base; fore tibia with 1 short ventral apical bristle (longer than width of fore tibia); outer epandrial lobe long and narrow ( Yang et al. 2011, fig. 443)............. H. longilobatus Yang et Saigusa

– Antenna black; fore tibia with 1 long apical ventral bristle (nearly as long as fore tarsomeres 1); outer epandrial lobe wide ( Yang et al. 2011, fig. 441)...................................................... H. latilobatus Yang et Saigusa

13 Basal segment of arista short, shorter than 0.3 times length of apical portion of arista.............................. 14

– Basal segment of arista long, about 0.4–0.6 times length of apical portion of arista................................ 16

14 Fore tibia with apical bristle........................................................................... 15

– Fore tibia without apical bristle......................................................... H. xinjianganus Yang

15 Male cercus brown ( Fig. 5 ).......................................................... H. galonglaensis sp. nov.

– Male cercus mainly brown, but yellowish at base ( Fig. 4)....................................... H. flavus sp. nov.

16 Mid and lower postocular bristles light yellow............................................................ 17

– All postocular bristles black........................................................................... 18

17 First flagellomere 1.7 times longer than wide, arista arising from middle; cercus nearly square ( Yang et al. 2011, fig. 432)........................................................................................... H. basalis Yang

– First flagellomere as long as wide, arista arising subapically; cercus nearly triangular ( Yang et al. 2011, fig. 450).................................................................................... H. subtruncatus Yang et Saigusa

18 Male cercus with short to long digitations................................................................ 19

– Male cercus only with short digitations.................................................................. 20

19 First flagellomere blunt at tip; inner epandrial lobe short and thin ( Yang et al. 2011, fig. 444). H. masunagai Yang et Saigusa

– First flagellomere sharp at tip; inner epandrial lobe long and strong ( Yang et al. 2011, fig. 435)................................................................................................... H. curviphallus Yang et Saigusa

20 Inner epandrial lobe long, nearly as long as outer epandrial lobe ( Yang et al. 2011, fig. 453).......... H. xizangensis Yang

– Inner epandrial lobe not obvious or very short............................................................ 21

21 Fore tibia with 1 long obvious ventral apical bristle........................................................ 22

– Fore tibia without obvious ventral apical bristle........................................................... 23

22 First flagellomere 1.8 times longer than wide, sharp at tip; femora blackish to black ( Yang et al. 2011, fig. 439)............................................................................................... H. hunanensis Yang

– First flagellomere 1.4 times longer than wide, blunt at tip; femora dark yellow ( Yang et al. 2011, fig. 438)............................................................................................ H. hubeiensis Yang et Saigusa

23 Inner epandrial lobe weak ( Yang et al. 2011, fig. 445).................................. H. medialis Yang et Saigusa

– Inner epandrial lobe obvious.......................................................................... 24

24 Femora black, but tip yellowish brown.............................................. H. serratus Yang et Saigusa

– Femora yellow, somehow dark at dorsum..................................................... H. dentalis Yang

25 Fore tibia with apical bristles.......................................................................... 26

–......................................................................... Fore tibia without apical bristle 29

26 Fore tibia with 3 apical bristles ( Fig. 1)...................................................... H. bisetus sp. nov.

– Fore tibia with 1 apical bristle......................................................................... 27

27 Hypandrium thick, with spinous digitations on base ( Yang et al. 2011, fig. 429)........... H. apicispinus Yang et Saigusa

–........................................................... Hypandrium without spinous digitations on base 28

28 Legs mainly black; outer epandrial lobe short and thick; male cercus with short digitations ( Yang et al. 2011, fig. 430)................................................................................. H. baishanzuensis Yang et Yang

– Legs mainly yellow; outer epandrial lobe long and narrow; male cercus with long digitations ( Yang et al. 2011, fig. 442)............................................................................. H. longidigitatus Yang et Saigusa

29 Legs mainly black.................................................................................. 30

– Legs mainly yellow....................................................................... H. nudus Yang

30 Phallus with 1 large, sharp dorsal tooth ( Fig. 14 )........................................... H. deltodontus sp. nov.

– Phallus without tooth ( Yang et al. 2011, fig. 451).................................. H. subtruncatus Yang et Saigusa

Figures

FIGURES 20 – 21. Hercostomus nuciformis sp. nov., male. 20. Antenna, scale bar = 0.2 mm; 21. Genitalia, lateral view, scale bar = 0.3 mm. Abbreviations: epn = epandrium, hyp = hypandrium, ph = phallus, sur = surstylus, lat = epandrial lobe, pos = postgonite, cer = cercus.

FIGURES 5 – 6. Hercostomus galonglaensis sp. nov. 5. Male; 6. Female. Scale bar = 1.0 mm.

FIGURES 13 – 15. Hercostomus deltodontus sp. nov., male. 13. Antenna, scale bar = 0.2 mm; 14. Genitalia, lateral view, scale bar = 0.5 mm; 15. Male cercus, scale bar = 0.5 mm. Abbreviations: epn = epandrium, hyp = hypandrium, ph = phallus, sur = surstylus, lat = epandrial lobe, pos = postgonite.