Key to known Nearctic pupae of Ablabesmyia

1. Respiratory duct opens laterally ¼ from apex of thoracic horn (Fig. 2 G); shagreen on tergites multibranched spinulae; all Lsetae of VII placed distinctly in posterior half.......................................... A. (Asayia) annulata (Say)

- Respiratory duct opens near apex; anal lobe at most with 16 spinules distad of distal setae and 5 on basal margin; at least L1 at, anterior of, or slightly posterior of centre of VII............................................................. 2

2. Respiratory duct and apical papilla more than 1/2 as long as thoracic horn................. A. (Karelia) peleensis (Walley)

- Respiratory duct and apical papilla not more than 1/10 as long as thoracic horn..................................... 3

3. Wing sheath with numerous freckle-like dots............................................ A. (Karelia) idei (Walley)

- Wing sheath without freckle-like dots...................................................................... 4

4. Apex of respiratory duct is a rounded "T" (Fig. 2 A–C)........................................................ 2

- Apex of respiratory club- or cone-shaped (Fig. 2 D–G)........................................................ 7

5.. Frontal apotome T-shaped (Roback 1985 fig. 287); wing sheath uniformly pigmented; thoracic comb (Fig. 2 B) consisting of 13–18 apically pointed 35–40 µm long spines; exuviae 5.7–6.9 mm long........ A. (Karelia) philosphagnos Beck et Beck

- Frontal apotome dome-shaped (Roback 1985 figs 288–298); wing pad clear or with faint wing pattern.................. 5

6. Wing pad with faint wing pattern; thoracic comb (Fig. 2 A) consisting of about 13–16 larger and10 minute spines.................................................................................... A. (Karelia) illinoensis (Malloch)

- Wing pad clear; thoracic comb (Fig. 2 B) consisting of 12–15 apically rounded, 72–115 µm long spines and a few smaller ones..................................................................... A. (Karelia) pulchripennis (Lundbeck)

7. Wing sheath with large dark maculae in area of basal veins R/M and anal vein (Caldwell 1993, fig. 8)............................................................................................. A. (Karelia) cinctipes (Johannsen)

- Wing sheath not as above, mostly showing vein pattern........................................................ 8

8. Wing sheath mostly uniformly pigmented with irregular clear maculae distributed near the margins, cross vein distinctly dark- ened, surrounded by a clear area, no indication of a vein pattern; cephalothorax mostly clear; abdominal segments II–V ante- rior margins pale, conjunctives laterally with distinct brown spot; respiratory duct S-shaped (Fig. 2 E), genital sac of male 0.65–0.75 times as long as anal lobe (Fig. 3 E)............................................ A. (A.) basalis (Walley)

- Wing sheath with brownish wing pattern; cephalothorax with a darkened pattern; abdominal segments II–V with dark anterior margins; conjunctives without dark spot, if darkened then more diffused towards the middle; respiratory duct straight or U- shaped (Fig. 2 D, F), genital sac 0.65–0.85 times as long as anal lobe............................................. 9

9. Wing sheath with vein pattern mostly obscured by pale and dark maculae, only R and M1+2 relatively distinct distally; abdomen with weak pattern................................................................ A. (A.) hauberi Beck et Beck

- Wing sheath with distinct vein pattern, with or without dark maculae............................................ 10

10. Wing sheath with veins terminating before the margin........................................................ 11

- Wing sheath with veins connecting to brownish margin....................................................... 12

11. Both L1 and L2 of VII situated in anterior half........................................... A. (A.) parajanta Roback

- At most L1 of VII in anterior half.................................... A. (A.) rhamphe Sublette, A. (A.) janta Roback

12. Veins of wing sheaths strong and broad, base of vein M may be absent...................... A. (A.) monilis auct. nec L.

- Veins of wing sheaths more faint, vein M generally complete.................................................. 13

13. Wing sheaths with spots in addition to veins............................................................... 14

- Wing sheaths with only veins........................................................... A. (A.) aspera Roback

14. Abdominal segment IV with strong pattern, lateral lines of pigment distinct; thoracic comb (Fig. 2 D) with 12–17 spines, the longest mostly shorter than 60 µm, occasionally with a number of additional minute spines; genital sac of male 0.75–0.85 times as long as anal lobe............................................................ A. (A.) mallochi (Walley)

- Abdominal segment IV unmarked; thoracic comb with 9–10 spines; genital sac of male 0.74 times as long as anal lobe....................................................................................... A. (A.) simpsoni Roback