Cryptochetum Rondani, 1875

Xi, Yuqiang & Yin, Xinming, 2020, Three new Cryptochetum Rondani, 1875 (Diptera: Cryptochetidae) from Yunnan Province, China and an identification key to Chinese species, European Journal of Taxonomy 605 (605), pp. 1-15 : 2-3

Key to species of Cryptochetum Rondani, 1875

1. Ocellar triangle small, separated from antennal base; costal vein (C) extending to vein M 1 ........... 2

– Ocellar triangle large, reaching antennal base; costal vein (C) extending to vein R 4+5 or slightly beyond apex of wing ......................................................................................................................... 3

2. Wing crossvein dm-m curved inward ( Fig. 22 ) .............................. C. curvatum Yang & Yang, 1996

– Wing crossvein dm-m perpendicular ( Fig. 23 ) ................................ C. deltatum Yang & Yang, 1996

3. Wing vein R 4+5 terminating at apex of wing ..................................................................................... 4

– Wing vein R 4+5 terminating before apex of wing, located between R 4+5 and M 1 .............................. 9

4. Wing vein M 1 between r-m and dm-m crossveins as long as dm-m crossvein ( Fig. 24 ) ...................................................................................... C. tianmuense Yang & Yang, 2001

– Wing vein M 1 between r-m and dm-m crossveins longer than dm-m crossvein .............................. 5

5. Wing vein M 1 between r-m and dm-m crossveins 2.0 × as long as dm-m crossvein ( Fig. 25 ) .......................................................................................... C. acutulum Yang & Yang, 1996

– Wing vein M 1 between r-m and dm-m crossveins <2.0 × as long as dm-m crossvein .................... 6

6. Wing vein M 1 between r-m and dm-m crossveins 1.2 × as long as dm-m crossvein ( Fig. 9 ) ..................................................................................................... C. glochidiatusum sp. nov.

– Wing vein M 1 between r-m and dm-m crossveins 1.5 × as long as dm-m crossvein ....................... 7

7. Antennal postpedicel slightly acute apically ( Fig. 26 ) .................. C. zalatilabium Xi & Yang, 2015

– Antennal postpedicel slightly blunt apically ..................................................................................... 8

8. Knob of haltere dark brown; distal portion of M 4 (part beyond crossvein dm-m) 2.0 × as long as dm-m crossvein ( Fig. 3 ) ......................................................................... C. euthyiproboscise sp. nov.

– Knob of haltere dark yellow; distal portion of wing vein M 4 (part beyond crossvein dm-m) 1.5 × as long as dm-m crossvein ( Fig. 17 ) ................................................................. C. longilingum sp. nov.

9. Costal wing vein (C) extending beyond end of vein R 4+5; vein M 1 between r-m and dm-m crossveins virtually as long as dm-m crossvein ( Fig. 27 ) ......................... C. kunmingense Yang & Yang, 1996

– Costal wing vein (C) extending to end of vein R 4+5; vein M 1 between r-m and dm-m crossveins shorter than dm-m crossvein ........................................................................................................... 10

10. Apex of wing situated medially between veins R 4+5 and M 1 ...........................................................11

– Apex of wing closer to vein R 4+5 than to vein M 1 ........................................................................... 13

11. Wing vein M 1 between r-m and dm-m crossvein as long as vein M 4 (part beyond dm-m crossvein) ( Fig. 28 ) ................................................................................ C. fanjingshanum Yang & Yang, 1988

– Wing vein M 1 between r-m and dm-m crossvein shorter than vein M 4 (part beyond dm-m crossvein) ........................................................................................................................................ 12

12. Distal portion of wing vein M 4 (part beyond dm-m crossvein) 1.7 × as long as dm-m crossvein; dm-m crossvein virtually straight ( Fig. 29 ) .................................. C. maolanum Yang & Yang, 1996

– Distal portion of wing vein M 4 (part beyond dm-m crossvein) 3.0 × as long as dm-m crossvein; dm-m crossvein slightly curved ( Fig. 30 ) ...................................... C. shaanxiense Xi & Yang, 2015

13. Mid section of dm-m crossvein appreciably curved ....................................................................... 14

– Mid section of dm- m crossvein perpendicular .............................................................................. 15

14. Antennal postpedicel wide and flat, margin inclined apically ( Fig. 31 ) ............................................. ........................................................................................................... C. yunnanum Xi & Yang, 2015

– Antennal postpedicel slightly narrow and short, margin blunt and rounded apically ( Fig. 32 ) ............................................................................. C. nonagintaseptem Yang & Yang, 1998

15. Ocellar triangle approximately in equilateral triangle .................................................................... 16

– Ocellar triangle approximately in obtuse triangle .......................................................................... 17

16. Apex angle of ocellar triangle slightly wider than distance between antennae; body slightly smaller (body length 1.5 mm) ( Fig. 33 ) .................................................... C. medianum Yang & Yang, 1998

– Apex angle of ocellar triangle slightly narrower than distance between antennae; body slightly larger (body length 3.5 mm) ( Fig. 34 ) ........................................................ C. sinicum Yang & Yang, 1996

17. Apical angle of ocellar triangle slightly wider than distance between antennae; antennal postpedicel acute apically ( Fig. 35 ) ........................................................... C. acuticornutum Yang & Yang, 1998

– Apical angle of ocellar triangle nearly equal to distance between antennae; antennal postpedicel with apical margin inclined inward ( Fig. 36 ) ....................................... C. beijingense Yang & Yang, 1996

Figures

Figs 22–29. Wings of eight species of Cryptochetum. 22. C. curvatum Yang & Yang, 1996. 23. C. deltatum Yang & Yang, 1996. 24. C. tianmuense Yang & Yang, 2001. 25. C. acutulum Yang & Yang, 1996. 26. C. zalatilabium Xi & Yang, 2015. 27. C. kunmingense Yang & Yang, 1996. 28. C. fanjingshanum Yang & Yang, 1988. 29. C. maolanum Yang & Yang, 1996. Scale bar = 0.1 mm

Figs 8–10. Cryptochetum glochidiatusum sp. nov., holotype, ♂ (CR122). 8. Head, lateral view. 9. Head, dorsal view. 10. Wing, dorsal view. Scale bar = 0.1 mm.

Figs 1–3. Cryptochetum euthyiproboscise sp. nov., holotype, ♂ (CR101). 1. Head, lateral view. 2. Head, dorsal view. 3. Wing, dorsal view. Scale bar = 0.1 mm.

Figs 15–17. Cryptochetum longilingum sp. nov., holotype (CR154), ♂. 15. Head, lateral view. 16. Head, dorsal view. 17. Wing, dorsal view. Scale bar = 0.1 mm.

Figs 30–36. Wings of seven species of Cryptochetum. 30. C. shaanxiense Xi & Yang, 2015. 31. C. yunnanum Xi & Yang, 2015. 32. C. nonagintaseptem Yang & Yang, 1998. 33. C. medianum Yang & Yang, 1998. 34. C. sinicum Yang & Yang, 1996. 35. C. acuticornutum Yang & Yang, 1998. 36. C. beijingense Yang & Yang, 1996. Scale bars = 0.1 mm.