Key to the Genera of Adult Ceratopogonidae in Costa Rica

The following key includes genera either known from or suspected of being in Costa Rica. A few others, presently known only from more southerly areas in the Neotropical Region are also included (Fittkauhelea, Leptohelea, Nannohelea, Lanehelea, Sphaerohelea, Clastrieromyia).

This key is intended to work for both alcohol and slide mounted material. I have indicated in bold type those character states which are best seen with a compound microscope (i.e. with slide mounted material), although with skill, practice and patience many of these character states may also be observed in alcohol specimens.

When the two claws at the end of a leg are the same size, they are referred to as being equal; conversely when they differ in size they are called unequal. The costal ratio is the length of the costa from the wing base (measured from the arculus), divided by the total wing length. Figures are provided in support of the key.

1. Eyes widely separated dorsally, lacking frontal suture (Fig. 1A); palp with 4 segments (only one beyond elongate and/or swollen third) (Fig. 1A); wing with crossvein r-m absent (Fig. 2A); radial cells fused into swollen unit (Fig. 2A); base of gonocoxites closely approximated ventrally
(Fig. 12A); female cerci very elongate (Fig. 15A)

LEPTOCONOPINAE..................................................................................................................... Leptoconops

- Eyes narrowly or widely separated dorsally, with frontal suture (Figs. 1B,C); palp with 2-5 segments; wing with crossvein r-m present (Fig. 2C); if radial cells fused these are not expanded into swollen unit (Figs. 2J, 3C); base of gonocoxites distinctly separated ventrally
(Figs. 12B-E, 13A-C, E-G, 14A-E), if fused ventrally (Fig. 13D), legs spinose (Fig. 8A) (Echinohelea); female cerci short (Fig. 15B-E).......................................................................................................................... 2

2. Wing with (Figs. 2B,E, G) or without numerous macrotrichiae; hind first tarsomere with scattered setae or, at most, a row of strong bristles (but these not forming a tight row, especially basally on the tarsomere) (Fig. 7B); female with two equal, small claws on each leg (Fig. 7C-E); with (Fig. 7C-D) or without well developed empodia ................................................................................................................ 3

- Wing bare or with scattered macrotrichiae on apical half of wing (a few species have some macrotrichiae more basally on the wing but these are scattered) (Figs. 3B, F); hind first tarsomere with row of palisade setae with at least more basal setae with abutting bases, some groups with an additional pronounced basal stout spine (Fig. 7A, 8A-C); females with two equal, small claws on each leg or with 1-2 claws on one or more of the legs which, in some, are large
(Fig. 7F, 8A-F, 9B-E); without well developed empodia............................................................................... 6

3. Eyes somewhat approximated to widely separated medially (Figs. 1B-H); male with setae on first flagellomere about as long as those on following flagellomeres; wing membrane with or without distinct patterns of dark and/or light pigmentation (Figs. 2F-G)................................................Culicoides

- Eyes broadly abutting medially; male with setae on first flagellomere short, less than 1/2 the length of those on following flagellomeres (Fig. 5C); wing without distinct patterns of pigmentation, if pigmentation present, it is restricted to a pattern of scales or faint markings on the membrane............................................................................................................................................................. 4

4. C reaching well beyond middle of wing (Fig. 2C-D); both radial cells well developed (Fig. 2C-D); paratergite well developed and bearing 1-3 setae (Fig. 6F) ................................................. Atrichopogon

- C short or long; if long, then second radial cell narrow (Fig. 2B); paratergite narrow, without setae (as in Fig. 6G)...................................................................................................................................................... 5

5. Apical flagellomere without terminal nipple (although it may be strongly tapered) (Fig. 5C); male flagellomeres sculptured (Fig. 5C); wing with second radial cell somewhat or completely truncated apically (Fig. 2E); without tibial spur on foreleg; claws only slightly curved (Fig. 7E); empodia poorly developed. DASYHELEINAE.......................................................................................................... Dasyhelea

- Apical flagellomere with terminal nipple which is constricted basally (Figs. 6A-B); male flagellomeres not sculptured; wing with second radial cell pointed apically (Fig. 2B); with tibial spur on foreleg; claws strongly curved (Fig. 7C-D); empodia vestigial or well developed
(Fig. 7CD)....................................................................................................................................... Forcipomyia

6. M forking beyond r-m (i.e. medial fork petiolate) (Fig. 3F), in some base of M2 not present
(Fig. 2H-J, 3C)...................................................................................................................................................... 7

- M forking at or before r-m (i.e. medial fork not petiolate) (Fig. 3D, 3J-L, 4A-H); base of M2 always present .............................................................................................................................................................. 31

7. Wing with reduced radial cells (some Brachypogon have one or two small radial cells)
(Fig. 2I-K, 3C); costal ratio less than 0.65 (Fig. 2I-K, 3C); female claws more or less equal (male of Rhynchohelea unknown but likely with broadly separated eyes, antennal flagellomeres 10 and 11 fused and a katepisternal seta) ........................................................................................................................ 8

- Wing with at least one well developed radial cell (Fig. 3B, F); costal ratio more than 0.50; female claws equal or unequal, some with only a single claw on one or more of the legs (males of Leptohelea and Cacaohelea unknown).......................................................................................................................................................... 13

8. Male antennal flagellomeres 10 and 11 fused or with less that 13 flagellomeres; wing with or without radial cells; katepisternum with 1 or more lateral setae (can be seen in alcohol specimens by holding specimen upright and looking along plane of thoracic pleura in outline)
(Fig. 6G) ............................................................................................................................................................... 9

- Male antenna with flagellomeres 10 and 11 separate and with 13 flagellomeres present; wing without radial cell (cells completely fused) (Fig. 2J-K, 3A); katepisternum without seta....10

9. Male flagellum with 7-8 flagellomeres (Fig. 5E); palpus with 3 segments (Fig.6B)................................................................................................................................ Nannohelea - Male flagellum with at least 9 flagellomeres (almost always with 13 but with 10 and 11 fused); palpus with 5 segments ....................................................................................................................................Brachypogon

10. Female antenna with 12 flagellomeres (Fig. 5D); female proboscis stout, truncate, with apical hooklike structures (Fig. 1D) ................................................................................................... Rhynchohelea (male unknown) - Female antenna with 13 flagellomeres; proboscis normal.......................................... 11

11. Palpus with 5 segments; wing length 0.7-0.8 mm ......................................................... Schizonyxhelea

- Palpus with 2 segments (Fig. 6A); wing length < 0.6 mm ....................................................................... 12

12. Fore tibia with apical spur; macrotrichiae confined to margin and apex of wing (in some, also a few on apex of M veins); costal ratio > 0.40 (Fig. 3K); male antenna with 6 separate flagellomeres (Fig. 5G).............................................................................................................................................. Baeohelea

- Fore tibia without apical spur; macrotrichiae long and abundant over entire wing; costal ratio < 0.36; male antenna with 12 flagellomeres but with 2-7, 8-9, and 10-11 fused (Fig.5F)......................................................................................................................................... Baeodasymyia

13. Wing with characteristic darkly mottled pigmentation, more or less scattered on membrane
(Fig. 3H)............................................................................................................................................. Monohelea

- Wing without pigmentation or, if present, restricted to radial sector or with discrete dots or stripes or with bands (Fig. 3B, E) ............................................................................................................................... 14

14. Costa extending nearly to tip of wing (Fig. 3G, I); female wing with costa extending beyond apex of second radial cell ........................................................................................................................................ 15

- Costa not extending beyond 0.85 of wing (Fig. 3B, F); female wing with costa ending at apex of second radial cell ............................................................................................................................................. 17

15. Palpus with 5 segments; female with clypeus not fused to head; female wing with first radial cell very small, second very elongate (Fig. 3I); female with single claw on each leg
(Fig. 8H)..................................................................................................................................... Parastilobezzia

- Palpus with 4 segments; female with clypeus laterally fused to head (Fig. 1F-G); female wing with 1 radial cell (Fig. 4F); female with two claws on each leg, although hindleg claws may be unequal ..... 16

16. Eyes moderately separated, bare (Fig. 1F); female claws without basal inner tooth.................................................................................................................................... Parabezzia (female)

- Eyes broadly separated, pubescent (Fig. 1G); female claws with basal inner tooth........ Fittkauhelea (female)

17. Male.............................................................................................................................................................. 18
- Female.............................................................................................................................................................. 24

18. Hind leg with single long claw and small basal tooth (Fig. 8B)............................................. Allohelea

- Hind leg with two equal claws .................................................................................................................... 19

19. Wing with 1 radial cell (Fig. 3B) .............................................................................................................. 20

- Wing with 2 radial cells ................................................................................................................................ 23

20. Fore coxa with long spine-like setae (Fig. 6H)....................................................................... Parabezzia

- Fore coxa with only simple setae (sometimes rubbed off in alcohol specimens) ................................ 21

21. Palp with four segments; without discrete dots or short stripes on veins............................................................................................................................................... Fittkauhelea

- Palp with five segments ............................................................................................................................... 22

22. Aedeagus continuous medially (as in Fig. 13C).............................................................. Alluaudomyia

- Aedeagus with two lateral sclerites (so that aedeagus appears to be split medially) (Fig. 13A, B) or with aedeagus very small and short............................................................................... Stilobezzia (in part)

23. Aedeagus with two lateral sclerites (so that aedeagus appears to be split medially) (Fig. 13A, B) or with aedeagus very small and short.......................................................................... Stilobezzia (in part)

- Aedeagus continuous medially (Fig. 13C) ............................................................................ Downeshelea

24. Wing with 1 radial cell (Fig. 2H, 2K, 3B) ................................................................................................ 25

- Wing with 2 radial cells (Fig. 2H, 3F, E) ..................................................................................................... 28
25. Palp with 3 segments (Fig. 6C); claws on legs small, equal (Fig. 8G) .............................. Leptohelea
- Palp with 5 segments; claws on legs enlarged, those on hindlegs a single talon or unequal

(Fig. 7F, 8D-F) .................................................................................................................................................. 26

26. Each leg with two claws which are more or less equal on the fore and midlegs but unequal on the hindleg (Fig. 7F) ......................................................................................................................... Alluaudomyia

- Each leg with a single claw (although each may have a basal tooth) (Fig. 8D-F, 9A)......................... 27

27. Eyes pubescent; second radial cell somewhat broad; medial vein reduced to a faint trace; single claw on each leg short, stout and sharp (Fig. 9A) .................................................... Cacaohelea (in part)

- Eyes bare; medial veins clearly visible but with base of M2 sometimes absent; claw on each leg elongate (Fig. 8D-F) ......................................................................................................... Stilobezzia (in part)

28. Wing with 2-3 dark bands (Fig. 3E); fore and midlegs each with 2 equal claws .............................. 29

- Wing with or without pigmentation but never as 2-3 dark bands; fore and midlegs each with a single claw (some with a smaller basal tooth) ............................................................................................. 30

29. Hind claw with basal tooth (Fig. 8B) ........................................................................................ .Allohelea
- Hind claw without basal tooth (Fig. 8C) ................................................................................ Downeshelea

30. Eyes pubescent; first radial cell barely visible with surrounding veins thickened (Fig. 2H); second radial cell somewhat broad; medial vein reduced to a faint trace; single claw on each leg short, stout and sharp (Fig.9A)..................................................................................... Cacaohelea (in part)

- Eyes bare; first radial cell small to well developed (Fig. 4F); second radial cell elongate; medial veins clearly visible but with base of M2 sometimes absent; claw on each leg elongate (Fig.8DF)............................................................................................................................. Stilobezzia (in part)

31. Fifth tarsomere of foreleg swollen (Figs. 9B, 10A, C) ................................................. HETEROMYIINI 32

- Fifth tarsomere of foreleg not swollen ....................................................................................................... 34

32. Fore femur very swollen, with numerous thick ventral spines (Fig. 10C) .........................Heteromyia

- Fore femur slender, with at most a few slender spines ............................................................................ 33

33. Fourth tarsomere of all legs cylindrical or slightly cordate and lacking strong spines; female hind leg strikingly elongate, with tarsomere 2 at least 3/4 the length of tarsomere 1 (Fig. 9C); hind claw very long, either single or with a small basal tooth, much longer than claws of fore and midlegs
(Fig. 9C)....................................................................................................................................... Pellucidomyia

- Fourth tarsomere of foreleg cordate, of mid and hindleg bifid and spinose (Fig. 10B); female hind leg not much longer than other legs, with tarsomere 2 less than 1/2 the length of tarsomere 1; 2 hind claws about same length as those on fore and midleg ............................................................. Clinohelea

34. Legs (including femora and tibiae) with numerous scattered spines (Fig. 8A); male genitalia very large with gonocoxites fused dorsally and ventrally (Fig. 13D); female genitalia with sternite 8 large and plate-like (Fig. 15B) ............................................................................................................... Echinohelea

- Legs with or without spines, if present then these restricted to fore femur or are arranged in one or more rows (Fig. 11A); male genitalia small or large, if large then gonocoxites not fused; female genitalia with sternite 8 moderately developed .......................................................................................... 35

35. Male ............................................................................................................................................................ 36

- Female ............................................................................................................................................................. 49

36. Gonostylus much reduced in size (Fig. 13F, 14C, E)............................................................................. 37

- Gonostylus clearly present (Fig. 14A-B, 14D) (male Lanehelea and Sphaerohelea are not known but likely key to at least this point) ..................................................................................................................... 39

37. Gonocoxite slender, lightly sclerotized, with parallel sides (Fig. 14E); gonostylus either not evident or a tiny apical appendage (Fig. 14E) ............................................................................. Nilobezzia

- Gonocoxite short and stout or more elongate and well sclerotized (Fig. 13F, 14C); gonostylus clearly present as a small apical appendage (Fig. 13F, 14C) ..................................................................... 38

38. Wing with 2 radial cells (Fig. 4H); gonocoxite of moderately length (Fig. 13F) ....... Clastrieromyia

- Wing with 1 radial cell (Fig. 4E); gonocoxite short, squat (Fig. 14C)............................... Phaenobezzia

39. Genitalia with gonocoxite and tergite 9 very elongate (Fig. 14D)....................................................... 40

- Genitalia more stout, with gonocoxite and tergite 9 not elongate (Fig. 14A-B)................................... 41

40. Wing with 2 radial cells (Fig. 4F)...................................................................................... Mallochohelea
.
- Wing with 1 radial cell ................................................................................................................... Neobezzia

41. Fifth tarsomeres with stout, blunt spines (Fig. 10G-I); genitalia tilted upright against end of abdomen; tergite 9 with single row of thick, stout setae (Fig. 13E)............................... Johannsenomyia

- Fifth tarsomere without thick spines, or if present, these more slender and sharply pointed
(Fig. 9F); genitalia directed posteriorly or somewhat pressed upright against end of abdomen; tergite 9 with scattered setae, never arranged in a single row of thick, stout setae .......................................... 42

42. With 1-2 stout setae on the cercus (Fig. 13G); parameres fused medially at their very bases
(Fig. 13G).......................................................................................................................................... Amerohelea

- With several to many setae on the cercus; parameres separate or more completely fused............... 43

43. Fore femur with stout spines (Fig. 11A)................................................................................................. 44

- Fore femur without stout spines ................................................................................................................. 45

44. Wing with 1 radial cell (Fig. 4D)........................................................................................ Bezzia (in part)

- Wing with 2 radial cells (Fig. 4C).................................................................................. Palpomyia (in part)

45. Body slender and dorsoventrally flattened; eyes broadly separated medially (Fig. 1H); 1 radial cell (Fig. 3L, 4A); legs long and slender ...................................................................................................... 46

- Body more stout and not dorsoventrally flattened; eyes narrowly or moderately separated; 1-2 radial cells; legs not unusually long ............................................................................................................. 47

46. Thorax broadly rounded anteriorly, without median spine; palpus with 4 segments; parameres fused apically (Fig. 12E) ................................................................................................................. Stenoxenus

- Thorax narrowed anteriorly, with erect anteriomedial projection; palpus with 5 segments; parameres separate apically (Fig. 14A) ..................................................................................................... Paryphoconus

47. Wing with 1 radial cell (Fig. 4D) ....................................................................................... Bezzia (in part)

- Wing with 2 radial cells (Fig. 4C) ................................................................................................................ 48

48. Hind femur greatly swollen (Fig. 11E).................................................................................... Pachyhelea

- Hind femur not greatly swollen (Fig. 11C) .................................................................. Palpomyia (in part)

49. Wing with M2 strongly bent near base (Fig. 4B)................................................................. Stenoxenus

- Wing with M2 with not or only slightly bent near base (Fig. 4C-H) ..................................................... 50

50. Tarsomere 5 armed ventrally with stout black blunt spines (Fig. 9E, 10G-I); abdomen without tergal apodemes; sternite 8 with posterolateral hair tuft (Fig. 15C)................................ SPHAEROMIINI

51 - Tarsomere 5 unarmed, or if with some spines, these are slender and with sharp tips (Fig. 9F); abdomen with (Fig. 15D-E) or without tergal apodemes (not visible in some teneral or young specimens); sternite 8 without hairtuft......................................................................................................... 56
51. Femora without spines; claws equal on foreleg, unequal on mid and hindlegs
(Fig. 10G-I).............................................................................................................................. Johannsenomyia

- Femora with or without spines; claws equal on all legs .......................................................................... 52

52. Claws gently curved distally, with slender basal tooth on internal side, if present
(Fig. 9D) ............................................................................................................................................................ 53

- Claws straight or flattened distally, with blunt external basal tooth
(Fig. 9E) ............................................................................................................................................................... 4

53. Costa extending nearly to wing tip..................................................................................... Sphaerohelea

- Costa extending to about 0.75-0.85 of wing length.................................................................... Lanehelea

54.Costa long, extending nearly to wing tip with costal ratio over 0.84.................................... Neobezzia

- Costa short, extending to less than 0.8 of wing length ........................................................................... 55

55. 2 radial cells (Fig. 4F); wing grayish hyaline, veins with some pigmentation, anterior veins prominent; scutum shining yellow to black with little or no "pollen" (a fine dusting, best seen in dried specimens); palpus with fifth segment as stout as the fourth (Fig. 6D) ............... Mallochohelea

- 1-2 radial cells; wing usually whitish, anterior veins usually pale and not prominent; scutum dull, usually with dense whitish to grayish pollen; palpus tapering apically with fifth segment more slender than fourth (Fig. 6E) ........................................................................................................... Nilobezzia

56. Body slender and dorsoventrally flattened; eyes broadly separated medially (as in Fig. 1H);
1 radial cell (Fig. 3L); legs long and slender, with fine setae; claws short ....................... Paryphoconus

- Body more stout and not dorsoventrally flattened; eyes narrowly or moderately separated;
1-2 radial cells; legs not unusually long, femora with or without stout spines; claws short or moderately elongate............................................................................................................ PALPOMYIINI 57

57. Abdomen with 1 pair of tergal apodemes; 1 spermathecae with no evidence of a reduced
second one...................................................................................................................................... Amerohelea

- Abdomen with 2 or more pairs of tergal apodemes (Fig. 15D-E); 1-2 spermathecae but if only one, a small reduced second one is present ........................................................................................................... 58

58. Wing with 2 radial cells (Fig. 4C) ............................................................................................................ 59

- Wing with 1 radial cell (Fig. 4D) .................................................................................................................. 61

59. Fore femur without stout spines; hind femur greatly swollen (Fig. 11E)...........................Pachyhelea

- Fore femur with or without stout spines (Fig. 11A); hind femur not greatly swollen
(Fig. 11C)............................................................................................................................................................ 60

60. M2 arising before r-m (Fig. 4C)................................................................................................. Palpomyia

- M2 arising from r-m (Fig. 4H) ................................................................................................Clastrieromyia

61. Costa moderately short with costal ratio 0.67-0.75 (Fig. 3D); fore femur with or without stout spines; fifth tarsomere without stout ventral spines.......................................................................... Bezzia

- Costa more elongate with costal ratio more than 0.80 (Fig. 3E); fore femur without stout spines;
fifth tarsomere with slender ventral spines or setae with sharp, bent tips
(Fig. 10F) ...................................................................................................................................... Phaenobezzia

Unique Features to Help Identify Ceratopogonidae

As an alternate to using the key, there are some features which can help to identify at least some Ceratopogonidae quite rapidly.

These are listed below.

- Last flagellomere with apical flagellomere with terminal nipple which is constricted basally
(Fig.5A, B): ......................................................................................................... Forcipomyia, Atrichopogon

- Male flagellomeres sculptured (Fig. 5C): ...............................................................Dasyhelea

- Female wing with M2 strongly bent near base (Fig. 4B) : ........................................ Stenoxenus

- Hind first tarsomere with row of palisade setae (Fig. 7A): ........................................... Ceratopogoninae
(all ceratopogonid genera except Leptoconops, Forcipomyia, Atrichopogon,
Dasyhelea)

- With well developed empodia (Fig. 7C-D): .................................... Forcipomyia, Atrichopogon

- Male fore coxa with numbers of elongate setae (Fig. 6H): ......................................... Parabezzia

- Male with a single hind claw (Fig. 8B): .................................................................. Allohelea

- Female with a single claw on each leg (Figs. 8F, H, 9A): ..................................... Parastilobezzia (short claws), Cacaohelea (short claws), Stilobezzia (elongate claws)

- Female with an extremely elongate single hind claw (Figs. 9C, 10E): .... Pellucidomyia, Heteromyia

- Female with only the hind leg with a single, moderately elongate claw (fore and midleg claws equal and much smaller) (Fig. 8B,C): ....................................................... Monohelea, Allohelea, Downeshelea.

- Gonocoxites fused ventrally (Fig. 13D): ................................................................................... Echinohelea

- Gonostylus much reduced in size (Figs. 13F, 14C, E): ..... Nilobezzia, Clastrieromyia, Phaenobezzia

- Aedeagus divided medially (so that it looks like there are two halves) (Fig. 13A,B): ........ Stilobezzia

- Female abdomen with tergal apodemes (Fig. 15D,E): ............................... Palpomyiini and Stenoxenini
(not present in individuals which have recently emerged).

- Female cerci very elongate (Fig. 15A): .............................................................. Leptoconops