Athyreacarus, Lindquist, Kaliszewski and Rack, 1990

Khaustov, Alexander A. & Frolov, Andrey V., 2020, First record of Athyreacaridae (Acari: Heterostigmata) from Asia with description of two new species of Athyreacarus from India and Sri Lanka, Zootaxa 4779 (2), pp. 260-272 : 270-271

Key to females of world species of Athyreacarus (based on Khaustov & Frolov 2019)

1. With two pairs of cheliceral setae (cha, chb)............................................................... 2

- With one pair of cheliceral setae (cha)..................................................................... 6

2. With three pairs of aggenital setae........................................................................ 3

- With two pairs of aggenital setae............................................. A. latus Khaustov and Frolov, 2019

3. Dorsal and ventral idiosomal setae not thickened in basal part, at least some dorsal idiosomal setae very long; cheliceral stylets without subapical tooth; tergites D, EF and H without scale-like microsculpture................................... 4

- Most dorsal and ventral idiosomal setae thickened in basal part, all dorsal idiosomal setae short; cheliceral stylets with subapical tooth; tergites D, EF and H with scale-like microsculpture................................ A. brevisetosus sp. nov.

4. Prodorsal shield with lateral projections; cupules on tergites D and EF not visible.................................. 5

- Prodorsal shield without lateral projections; cupules on tergites D and EF well developed................................................................................................ A. primitivus Khaustov and Frolov, 2017

5. Setae sc 1 distinct, at least 6 in length; ap1 narrow, almost as wide as ap2.......... A. angustus Khaustov and Frolov, 2019

- Only alveoli of setae sc 1 present; ap1 wide, much wider than ap2.................. P. ovalis Khaustov and Frolov, 2019

6. Setae c 1 absent, setae v 2 vestigial; setae sc 2, c 2, d and f shorter than greatly attenuated ps 1,2 ........................... 7

- Setae c 1 present, setae v 2 well developed; setae sc 2, c 2, d and f ultralong, exceeding setae ps 1,2 in length................. 8

7. Setae sc 2, c 2, d, f, h 1, and h 2 with distinctly thickened basal half; setae e very short, spiniform; dimples on segment ps small, similar to dimples on tergite H and aggenital plate............................. A. grandis Khaustov and Frolov, 2019

- Setae sc 2, c 2, d, f, h 1, and h 2 not thickened; setae e well developed, filiform; dimples on segment ps large, distinctly larger than dimples on tergite H and aggenital plate......................... A. pleiotretus Lindquist, Kaliszewski and Rack, 1990

8. At least alveoli of setae sc 1 present; cupules ih present; setae ag 1 distinctly blunt-ended............................. 9

- Setae sc 1 completely absent; cupules ih absent; setae ag 1 pointed................................. A. indicus sp. nov.

9. With two pairs of aggenital setae........................................................................ 10

- With three pairs of aggenital setae....................................................................... 11

10. Setae c 2 about 10 times longer than c 1; most of dorsal and ventral idiosomal setae pointed; length of idiosoma 420-450........................................................................ A. vazdemelloi Khaustov and Frolov, 2019

- Setae c 2 at most three times longer than c 1; most of dorsal and ventral idiosomal setae blunt-ended; length of idiosoma 240- 270.................................................................. A. pusillus Khaustov and Frolov, 2019

11. At least setae tc” on tarsi II and III with spatulate tips; apodeme 3 well separated from apodeme 4 on either side........ 12

- All setae on tarsi II and III with pointed tips, none with spatulate tips; apodeme 3 nearly contiguous with apodeme 4 on either side................................................................... A. similis Khaustov and Frolov, 2019

12. Setae tc’ on tarsi II and III with distinctly spatulate tips; dimples of idiosomal plates relatively large, sparsely distributed; length of idiosoma 440-465.................................................. A. magnificus Khaustov and Frolov, 2019

- Setae tc’ on tarsi II and III with pointed tips; dimples of idiosomal plates very small, densely distributed; length of idiosoma 305-405.............................................................. A. variabilis Khaustov and Frolov, 2019