Macrurohelea

Spinelli, Gustavo R., Ronderos, Maria M. & Grogan, William L., 2022, Five new species in the predaceous midge genus Macrurohelea Ingram & Macfie from Argentina, and descriptions of the previously unknown males of M. kuscheli Wirth and M. monotheca Spinelli & Grogan (Diptera: Ceratopogonidae), Zootaxa 5093 (4), pp. 445-464 : 446-447

Key to Macrurohelea of the Neotropical region

(females of M. similis Spinelli & Grogan , M. morenoi n. sp. and M. ventanensis n. sp., and the males of M. fuscipennis Spinelli & Grogan and M. wirthi Spinelli & Grogan are unknown)

1. Females............................................................................................. 2

- Males............................................................................................. 15

2. One spermatheca......................................................................................3

- Two spermathecae ( Figs. 4 , 11 , 29 )....................................................................... 4

3. Large species (wing length 2.05 mm); wing with intercalary vein in cell r 3; wing membrane infuscated, veins dark brown............................................................................. M. monotheca Spinelli & Grogan

- Medium-size species (wing length 1.59–1.74 mm); wing without intercalary vein in cell r 3; wing membrane hyaline, veins pale.......................................................................... M. gentilii Spinelli & Grogan

4. Legs with numerous long bristly setae......................................................... M. setosa Wirth

- Legs with vestiture of short setae......................................................................... 5

5. Large species (wing length 2.70 mm); anal lobe of wing well developed, broad............. M. thoracica Ingram & Macfie

- Smaller species (wing length 0.94–1.80 mm); anal lobe of wing poorly developed.................................. 6

6. Tarsal claws with bifid tips..................................................... M. paracaudata Grogan & Wirth

- Tarsal claws with entire pointed tips...................................................................... 7

7. Wing with intercalary vein in cell r 3 ( Fig. 28 )............................................................... 8

- Wing without intercalary vein in cell r 3 ( Figs. 3 , 10 )......................................................... 10

8. Intercalary vein very faint, not forked ( Fig. 28 )................................................... .. M. sirii n. sp.

- Intercalary vein forked................................................................................. 9

9. Flagellomeres 9–13 greatly elongate, antennal ratio1.61................................. M. wirthi Spinelli & Grogan

- Flagellomeres 9–13 very short, antennal ratio 1.00..................................... M. caudata Ingram & Macfie

10. Proximal 1/3 of wing membrane whitish hyaline, clearly contrasting with distal 2/3 darkly infuscated............................................................................................ M. fuscipennis Spinelli & Grogan

- Wing membrane hyaline or slightly infuscated, but uniformly pigmented (only slightly darkest on distal ½ of cell r 3 in M. donatoi n. sp.)....................................................................................... 11

11. Small species (wing length 0.94 mm); flagellomeres 9–13 very short (antennal ratio 0.59)............... M. kuscheli Wirth

- Larger species (wing length 1.27–1.80 mm); flagellomeres 9–13 elongate (antennal ratio1.10–1.36)................... 12

12. Thorax, excluding legs, dark brown, legs and abdomen yellowish ( Figs. 2, 4 ).......................... M. bassoi n. sp.

- Thorax and abdomen with same coloration................................................................ 13

13. Halter pale; spermathecae spheroidal with short necks.................................... M. irwini Grogan & Wirth

- Halter light or dark brown; spermathecae ovoid with long, slender necks........................................ 14

14. Wing membrane infuscated brown, slightly darkest on distal ½ of cell r 3 ( Fig. 10 ); spermathecae large (longest 80–82 µm long) with necks ca. 20 µm long................................................................. M. donatoi n. sp.

- Wing membrane uniformly lightly infuscated; spermathecae smaller (longest 53 µm long) necks ca. 15 µm long....................................................................................... M. yamana Spinelli & Grogan

15. Tip of parameres with hooked, slender process ( Figs. 41 , 49 ).................................................. 16

- Tip of parameres without hooked process ( Figs. 37, 39 , 43, 45 , 47 )..............................................17

16. Antennal flagellomeres 4–9 fused ( Fig. 15 ); second radial cell 0.95–1.76x longer than first; distal portion of aedeagus heavily sclerotized, slender, with bifid tip ( Fig. 42 ).................................................... M. kuscheli Wirth

- Antennal flagellomeres 4–9 separated ( Fig. 33 ); second radial cell twice as long as first ( Fig. 35 ); distal portion of aedeagus lightly sclerotized, ending in a quadrate hyaline process ( Figs. 36 , 50 )........................... M. ventanensis n. sp.

17. Legs with numerous long bristly setae.......................................................... M. setosa Wirth

- Legs with vestiture of short setae........................................................................ 18

18. Gonostylus bent abruptly subapically at 90°.......................................... M. gentilii Spinelli & Grogan

- Gonostylus curved or straight, but not bent abruptly subapically at 90°.......................................... 19

19. Aedeagus Y-shaped or V-shaped, basal arch stout or slender, distal portion short or elongate ( Figs. 46 , 48 ).............. 20

- Aedeagus triangular or tongue-shaped ( Figs. 38, 40 , 44 , 50 )................................................... 23

20. Large species (wing length 2.20 mm); aedeagus Y-shaped, with slender basal arch and distal portion elongate, slender; scutum, scutellum and post-scutellum golden brown; anal lobe of wing well developed, broad....... M. thoracica Ingram & Macfie

- Smaller species (wing length 0.80–1.74 mm); aedeagus with stout basal arch and distal portion short; scutum, scutellum and post-scutellum dark brown; anal lobe of wing poorly developed............................................... 21

21. Sternite 9 with posteromedian excavation......................................... M. paracaudata Grogan & Wirth

- Sternite 9 without posteromedian excavation ( Figs. 25 , 32 )................................................... 22

22. Aedeagus V-shaped, very broad basally, broader than bases of parameres, distal portion triangular, divided medially, apices slightly divergent ( Fig. 46 ); distal portion of parameres stout, nearly straight, slightly divergent distally, apex rounded ( Fig. 45 )................................................................................... M. morenoi n. sp.

- Aedeagus Y-shaped, moderately narrow basally, slightly narrower than bases of parameres, distal portion slender, apex entire, pointed ( Fig. 48 ); distal portion of parameres slender, apices tapered, divergent, with pointed tips ( Fig. 47 ).... M. sirii n. sp.

23. Gonostylus abruptly curved at mid-length, distal ½ highly modified with basomesal hump and broad foot-shaped apex ( Fig. 7 ); distal portion of parameres with bulbous tips ( Figs. 7 , 37 )......................................... M. bassoi n. sp.

- Gonostylus curved or nearly straight, distal ½ not modified ( Figs. 14 , 21 ); distal portion of parameres nearly straight, slender or stout, without bulbous tip ( Figs. 39 , 43 )................................................................ 24

24. Parameres disjunct ( Figs. 39 , 43 ); gonostylus moderately curved with broad tip ( Figs. 14 , 21 )....................... 25

- Parameres entire; gonostylus greatly curved with pointed tip.................................................. 27

25. Distal portion of parameres disjunct at mid-length.................................... M. yamana Spinelli & Grogan

- Distal portion of parameres disjunct subapically ( Figs. 39 , 43 )................................................. 26

26. Apicolateral process of tergite10 with short inner peg; sternite 9 with narrow shallow posteromedian excavation; gonostylus 0.85 length of gonocoxite ( Fig. 14 ); aedeagus with convex lateral margins and slender basal arms ( Fig. 40 ).................................................................................................... M. donatoi n. sp.

- Apicolateral process of tergite 10 without short peg; sternite 9 with deep posteromedian excavation; gonostylus 0.69 length of gonocoxite ( Fig. 21 ); aedeagus with straight lateral margins and stout basal arms with truncate apices ( Fig. 44 )...................................................................................... M. monotheca Spinelli & Grogan

27. Gonostylus nearly straight, moderately short (length 0.50 mm); distal portion of parameres with tips bent 90°............................................................................................ M. irwini Grogan & Wirth

- Gonostylus greatly curved, elongate (length 0.77–0.85 mm); distal portion of parameres tapering near apex with slightly bent pointed tips......................................................................................... 28

28. Cerci elongate, extending beyond tergite 10; aedeagus triangular, basal arch extending ½ of total length, tip pointed; distal portions of parameres divergent.................................................... M. similis Spinelli & Grogan

- Cerci shorter, not extending beyond tergite 10; aedeagus with very shallow basal arch, tip truncate; distal portions of parameres parallel....................................................................... M. caudata Ingram & Macfie

Figures

FIGURES 1–7. Macrurohelea bassoi n. sp. Allotype female, 1–4. Holotype male, 5–7. 1, 5 head. 2 thorax. 3, 6 wing. 4 tip of abdomen. 7 genitalia. Scale bars = 0.05 mm.

FIGURES 8–14. Macrurohelea donatoi n. sp. Allotype female, 8–11. Holotype male, 12–14. 8, 12 head. 9 thorax. 10, 13 wing. 11 tip of abdomen. 14 genitalia. Scale bars = 0.05 mm.

FIGURES 26–32. Macrurohelea sirii n. sp. Allotype female, 26–29. Holotype male, 30–32. 26, 30 head. 27 thorax. 28, 31 wing. 29 tip of abdomen. 32 genitalia. Scale bars = 0.05 mm.

FIGURES 37–42. Macrurohelea bassoi n. sp. Holotype male, 37–38. Macrurohelea donatoi n. sp. Holotype male, 39–40. Macrurohelea kuscheli Wirth, male, 41–42. 37, 39, 41 parameres. 38, 40, 42 aedeagus.

FIGURES 47–50. Macrurohelea sirii n. sp. Holotype male, 47–48. Macrurohelea ventanensis n. sp. Holotype male, 49–50. 47, 49 parameres. 48, 50 aedeagus.

FIGURES 43–46. Macrurohelea monotheca Spinelli & Grogan, male, 43–44. Macrurohelea morenoi n. sp. Holotype male, 45–46. 43, 45 parameres. 44, 46 aedeagus.

FIGURES 15–21. Macrurohelea kuscheli Wirth, male, 15–18. Macrurohelea monotheca Spinelli & Grogan, male, 19–21. 15, 19 head. 16 thorax. 17, 20 wing. 18-21 genitalia. Scale bars = 0.05 mm.

FIGURES 33–36. Macrurohelea ventanensis n. sp. Holotype male. 33 head. 34 thorax. 35 wing. 36 genitalia. Scale bars = 0.05 mm.

FIGURES 22–25. Macrurohelea morenoi n. sp. Holotype male. 22, head. 23 thorax. 24 wing. 25 genitalia. Scale bars = 0.05 mm.