Acerentomidae, Silvestri, 1907

Shrubovych, Julia & D’Haese, Cyrille, 2024, Phylogeny of Australian Acerentomidae species (Protura: Acerentomidae), with a key to identification, Zootaxa 5453 (1), pp. 86-104 : 101-102

Key to Australian Acerentomidae species

1. Abdominal legs II and III with 3 setae..................................................................... 2

- Abdominal legs II and III with 2 setae.................................................................... 12

2. Labial palps with apical tuft of setae, abdominal sternite VIII with 6 setae ( Acerentulus )............................. 3

- Labial palps without apical tuft of setae, abdominal sternite VIII with 4 setae...................................... 4

3. Sensillum a long, extending past base of t2, a’ short and slender, not reaching base of b’ .................................................................................................... Acerentulus confinis (Berlese, 1908) 1

- Sensillum a short, not reaching base of t2, a’ long and broadened, extending past base of b’ ...................................................................... Acerentulus sexpinatus Womersley, 1936 (South and Western Australia)

4. Striate band with distinct, parallel-sided striae ( Australentulus )................................................. 5

- Striate band reduced, striae invisible, hoog-shaped design presents.. Amphientulus ambiguus ( Tuxen, 1967) (South Australia)

5. Abdominal tergite I with P1a setae....................................................................... 6

- Abdominal tergite I without P1a setae..................................................................... 9

6. Tergite VII with 8 A -setae (setae A1 present)................................................................ 7

- Abdominal tergite VII with 6 A -setae (setae A1 absent)............ Australentulus victoriae Tuxen, 1967 (South Australia)

7. Labrum protruded, LR = 7.0, comb with 15 long teeth...... Australentulus occidentalis ( Womersley, 1932) (West Australia)

- Labrum not protruded, LR more than 10, comb with less than 10 teeth........................................... 8

8. Foretarsal sensillum a long and b short, both reaching base of seta γ3, comb with 9 teeth.................................................................................... Australentulus noseki Tuxen, 1967 (West Australia, India)

- Foretarsal sensillum a short, reaching base of sensillum t2, b long, extending past base of seta γ3, comb with 5 teeth................................................. Australentulus westraliensis ( Womersley, 1932) (West Australia, Victoria)

9. Labrum long, LR = 5.0, abdominal tergite V with 8 A -setae (setae A4 present), tergite VII with 18 P -setae (P3a present).................................................. Australentulus reginae Tuxen, 1967 ( West Australia, type area only)

- Labrum short, LR more than 10.0, abdominal tergite V with 6 A -setae (setae A4 absent), abdominal tergite VII with 16 P -setae (setae P3a absent).................................................................................... 10

10. Sensillum a sword-shaped; b short, reaching base of seta γ3; sensillum a’ slender; comb with 9 long teeth...................................................................... Australentulus intermedius Tuxen, 1967 (West Australia)

- Sensillum a parallel-sided; b longer, extending pass base of seta γ3; sensillum a’ broadened; comb with 5–8 short teeth... 11

11. Sensillum b short, reaching base of seta γ3, e not reaching the base of claw, comb with 8 short teeth..................................................................... Australentulus australensis ( Womersley, 1932) (West Australia) 2

- Sensillum b longer, extending past base of seta γ3, e reaching the base of the claw, comb with 6 short teeth................................................................... Australentulus tillyardi ( Womersley, 1932) (South Australia)

12. Abdominal legs II and III with long subapical and very short medial apical setae.................................. 13

- Abdominal legs II and III with lateral apical seta more than half as long as the subapical setae....................... 16

13. Striate band with distinct, parallel-sided striae.................................................................... Gracilentulus gracilis (Berlese, 1908) 3 (Europe, Morocco, South Africa, North America, New Zealand, South Australia)

- Striate band reduced to two lines, striae invisible........................................................... 14

14. Foretarsal sensillum t1 baculiform, abdominal tergite VI with 8 A -setae, abdominal sternite I with 4 P -setae....................................................... Berberentulus capensis (Womersley, 1931) (warmer regions of the world)

- Foretarsal sensillum t1 claviform, abdominal tergite VI with 6 A -setae, abdominal sternite I with 2 P -setae............. 15

15. Abdominal tergite VII with 2 A -setae (A5) and 16 P -setae (absence of P3a)..................................................................................... Baculentulus pseudonitidus Tuxen & Imadaté, 1975 (West Australia)

- Abdominal tergite VII with 4 A -setae (A4, 5) and 18 P -setae (presence of P3a)..... Baculentulus breviunguis (Condé, 1961) 4

16. Striate band on VIII with easily visible striae, abdominal sternite VIII with 6 setae, accessory setae sensilliform on abdominal segments I–VI ( Tasmanentulus )......................................................................... 17

- Striate band on VIII without striae, “hook-shaped” design present, abdominal sternite VIII with 4 setae, accessory setae setiform on abdominal segments I–VI ( Amphientulus ).............................................................. 18

17. Foretarsal sensillum b’ present, tergite VII with 8 A -setae (A1, 2, 4, 5).............................................................................. Tasmanentulus tasmanicus ( Tuxen, 1967) (Western and South Australia, Tasmania)

- Foretarsal sensillum b’ absent, tergite VII with 6 A -setae (A2, 4, 5)........ Tasmanentulus similis ( Tuxen, 1967) (Tasmania)

18. Abdominal tergites I–VI with P1a setae.................................................................. 19

- Abdominal tergites I–VI without P1a setae................................................................ 20

19. Abdominal sternite I with 4 P -setae, tergite VII with 8 A -setae (setae A1 present), foretarsal sensillum a’ sword-shaped, b’ slender, length of foretarsus 90 μm............................. Amphientulus validus ( Tuxen, 1967) (South Australia)

- Abdominal sternite I with 2 P -setae, tergite VII with 6 A -setae (setae A1 absent), foretarsal sensillum a’ slender, b’ broadened, length of foretarsus 55 μm.................................. Amphientulus aestuarii ( Tuxen, 1967) (South Australia)

20. Abdominal sternite I with 4 P -setae...................................................................... 21

- Abdominal sternite I with 2 P -setae...................................................................... 22

21. Abdominal tergite VII with 8 A -setae (setae A1 present); comb with 8 very short teeth; foretarsal sensillum a long, reaching base of seta γ3; length of foretarsus 50 μm....................... Amphientulus grangarae ( Tuxen, 1967) (Western Australia)

- Abdominal tergite VII with 6 A -setae (setae A1 absent); comb with semicircle hind margin and 5 teeth of different lengths; sensillum a short, reaching base of sensillum t2; length of foretarsus 75 μm................................................................................................ Amphientulus sinuous ( Tuxen, 1967) (South Australia).

22. Abdominal tergites II–VI with P4a setae, tergite VII with 8 A -setae (seta A1 sometimes present asymmetrically); foretarsal sensilla a and g slender; length of foretarsus 80 μm..................... Amphientulus markstivensi sp. nov. (Tasmania)

- Abdominal tergites II–VI without P4a setae; tergite VII with 6 A -setae (seta A1 absent); foretarsal sensilla a and g broadened; length of foretarsus 55 μm.................................... Amphientulus alienus ( Tuxen, 1967) (South Australia)