Key to Adult Stilobezzia of Mexico

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

- Males..............................................................................................14

2 Wing with 1 radial cell; fore femur with 2–4 stout black ventral spines........... S. (Eukraiohelea) elegantula (Johannsen)

- Wing with 2 radial cells; fore femur without ventral spines.....................................................3

3 Wing membrane with numerous macrotrichia primarily in cells r3 and m1 (Fig.17) … S. ( Acanthohelea).................4

- Wing membrane bare or with a few macrotrichia only on anterior margin in cell r3 S. ( Stilobezzia)......................5

4 Scutellum yellow on mid portion; wing hyaline.............................................. S. (A.) fuscula Wirth

- Scutellum dark brown; wing infuscated (Fig. 17)............................................ S. (A.) spinellii, n. sp.

5 Wing with 2 or 3 dark spots on anterior margin.............................................................. 6

- Wing hyaline or infuscated, without dark spots on anterior margin..............................................10

6 Fore tibia with numerous small dark spots; scutum with short anterior tubercle..................................... 7

- Fore tibia without numerous small dark spots; scutum with or without anterior tubercle........................... … 8

7 Wing with 2 dark spots, on r-m crossvein and very small one at base of 2nd radial cell................. S. (S.) kiefferi Lane

- Wing with 3 dark spots, on r-m crossvein, and 2 others at base and apex of 2nd radial cell........... S. (S.) punctulata Lane

8 Mesonotum yellow, without anterior tubercle; wing hyaline, with distinct brown spots on r-m crossvein and at level of 2nd radial cell; legs yellow, narrow apices of hind femur and tibia brown.......................... S. (S.) coquilletti Kieffer

- Mesonotum brown, with anterior tubercle; wing brownish, anterior margin with 2 or 3 dark spots; legs with extensive brown bands............................................................................................... 9

9 Fifth tarsomeres with ventral batonnets; wing with 3 dark spots, including 1 on apex of 2nd radial cell.... S. (S.) rabelloi Lane

- Fifth tarsomeres without ventral batonnets; wing with 2 dark wing spots, none on apex of 2nd radial cell.. S. (S.) beckae Wirth

10 Fifth tarsomeres with ventral batonnets................................................................... 11

- Fifth tarsomeres without ventral batonnets.................................................................13

11 Mid femur blackish on proximal 2/3; abdomen shining black......................... S. (S.) femoralis Lane & Forattini

- Mid femur pale; abdomen pale green or yellowish...........................................................12

12 Femora, tibiae whitish, hind femur with faint dark apical band.................................. S. (S.) glauca Macfie

- Femora, tibiae yellowish, hind femur with solid dark apical band............................... S. (S.) maculata Lane

13 Mesonotum dark brown, with large pruinose gray spots; tibiae with sub-basal pale bands.............. S. (S.) hirta Borkent

- Mesonotum uniform light grayish brown without spots; tibiae without bands............... S. (S.) pallidiventris (Malloch)

14 Wing with 1 radial cell; fifth tarsomeres with ventral batonnets; fore femur with 3–4 ventral spines.......................................................................................... S. (Eukraiohelea) elegantula (Johannsen)

- Wing with 2 radial cells; fifth tarsomeres with or without ventral batonnets; fore femur without ventral spines...........15

15 Wing with 2 or 3 dark spots on anterior margin............................................................. 16

- Wing without dark spots...............................................................................20

16 Fore tibia with numerous small dark spots; scutum with short anterior tubercle.................................... 17

- Fore tibia without numerous dark spots; scutum with or without anterior tubercle..................................18

17 Aedeagus with an oblique pair of doubly sinuate sclerites with sickle-shaped apices; parameres with slender tapered apices that are abruptly bent ventrocephalad.......................................................... S. (S.) kiefferi Lane

- Aedeagus with a pair of dark brown lateral sclerites with pointed tips; parameres separate with 2 elongate sclerites with sharply pointed apices that are posteriorly directed................................................ S. (S.) punctulata Lane

18 Hind tibia with stout, black setae on dorsal surface; parameres with a pair of basolateral L-shaped sclerites..................................................................................................... S. (S.) rabelloi Lane

- Hind tibia without stout, black setae on dorsal surface; parameres without a pair of basolateral L-shaped sclerites........19

19 Legs yellow, narrow apices of hind femur and tibia brown; aedeagal sclerites with rounded apices... S. (S.) coquilletti Kieffer

- Legs dark brown, hind femur with narrow subapical lighter band; aedeagal sclerites with slender apices that are recurved 120̊, tips pointed.......................................................................... S. (S.) beckae Wirth

20 Wing membrane with numerous macrotrichia primarily in cells r3 and m1 (Fig. 16) S. ( Acanthohelea)..................21

- Wing membrane bare or with a few macrotrichia on only anterior margin of cell r3… S. ( Stilobezzia)....................22

21 Gonocoxite with an elongate black spine on mesal margin; parameres with apices gradually narrowed to fine apical filaments that are recurved...................................................................... S. (A.) fuscula Wirth

- Gonocoxite without an elongate black spine on mesal margin; parameres with distal portions broad, straight, apicolateral mar- gins spoon-like (Figs. 21, 23)........................................................... S. (A.) spinellii, n. sp.

22 Abdomen with distinctive dark stripes on tergites 4–5 or single dark band on 5.................................... 23

- Abdomen without distinctive dark markings on tergites.......................................................24

23 Aedeagus with an oblique pair of long, straight, slender, sclerotized bars.......................... S. (S.) glauca Macfie

- Aedeagus with oblique pair of sclerotized bars, apices gradually narrowed to a fine apical filament..... S. (S.) maculata Lane

24 Abdomen shining black; hind femur black........................................ S. (S.) femoralis Lane & Forattini

- Abdomen yellow or pale; hind femur yellow or pale brown...................................................25

25 Gonostylus tapering distally to slender pointed tip.................................... S. (S.) pallidiventris (Malloch)

- Gonostylus not tapered, with broad rounded apex............................................. S. (S.) hirta Borkent