Nipponentomon, Imadate & Yosii, 1959

Shrubovych, Julia, Sternalski, Jakub & Smykla, Jerzy, 2025, Reexamination of three North American Nipponentomon species (Protura, Acerentomidae, Nipponentominae) with updated key to identification, Zootaxa 5604 (3), pp. 373-382 : 380-381

Updated key to the world Nipponentomon species

1. Tergites II– V with 18 P -setae (P3a present)................................................................ 2

– Tergites II– V with 16 P -setae (P3a absent)................................................................. 5

2. Meso- and metanota with P2a’ setae...................................................................... 3

– Meso- and metanota without P2a’ setae................................................................... 4

3. Meso- and metanota with P1a’ setae............... N. uenoi uenoi Imadaté & Yosii, 1959 (Far East: China, Japan, Korea)

– Meso- and metanota without P1a’ setae............ N. uenoi paucisetosum Imadaté, 1965 (Far East: China, Japan, Korea)

4. Tergite I with 16 P -setae.............................................. N. kamui Imadaté, 1965 (Far East: Japan)

– Tergite I with 14 P -setae..................................... N. aureitarsum ( Ewing, 1940) (North America: USA)

5. Tergites VI and VII with 18 P -setae (P3a present).................... N. bifidum Rusek, 1974 (North America: Canada)

– Tergites VI and VII with fewer than 18 P -setae............................................................. 6

6. Tergite VI with 16 P -setae (P1a present), tergite VII with 16 or 14 P -setae....................................... 7

– Tergites VI and VII with 14 P -setae (P1a absent)........................ N. jaceki Shrubovych, 2009 (Far East: Russia)

7. Tergite VII with 14 P -setae (P1a absent).................................................................. 8

– Tergite VII with 16 P -setae (P1a present).................................................................. 9

8. Sternites IV‒ VI with five A -setae, foretarsal sensillum a’ level with base of t2 ............................................................................................. N. khabarovskense Nakamura, 2004 (Far East: Russia)

– Sternites IV‒ VI with three A -setae, foretarsal sensillum a’ distal to base of t2 ................................................................................................. N. imadatei Bu, Wu & Yin, 2013 (Far East: China)

9. Tergite VIII with eight A -setae.................................... N. kevani Rusek, 1974 (North America: Canada)

– Tergite VIII with less than eight A -setae.................................................................. 10

10. Tergite VIII with six A -setae, sternite I with 4 P -setae....................................................... 11

– Tergite VIII with four A -setae, sternite I with two P -setae................................................................................................... N. pembertonense Bernard & Biechele, 2008 (North America: USA)

11. Sternite VII with five A -setae.............................. N. bidentatum Nakamura, 2004 (Far East: China, Russia)

– Sternite VII with three A -setae......................................................................... 12

12. Tergite I with eight or six A -setae; foretarsal sensillum t3 short, shorter than half of t1 length........................ 13

– Tergite I with four A -setae; sensillum t3 relatively long, longer than half of t1 length............................................................................................. N. andrei ( Ewing, 1940) (North America: USA)

13. Meso- and metanota with P2a’ setae, sternite III with six P -setae.............................................. 14

– Meso- and metanota without P2a’ setae, sternite III with five P -setae........................................... 15

14. Tergite I with eight A -setae and 14 P -setae, accessory setae on tergites VI –VII setiform.................................................................................... N. heterothrixi Yin & Xie, 1993 (Far East: China, Korea)

– Tergite I with six A -setae and 16 P -setae, accessory setae on tergites VI –VII sensilliform............................................................................................ N. taiga Shrubovych, 2013 (Far East: Russia)

15. Foretarsal sensillum b extremely long, its apex surpassing base of claw, foretarsal setae β1 and δ4 sensiliform.................................................................... N. californicum ( Hilton, 1929) (North America: USA)

– Foretarsal sensillum b not longer than sensillum c, foretarsal setae β1 and δ4 setiform.............................................................................. N. nippon ( Yoshii, 1938) (Far East; China, Japan, Korea, Russia).