Key to genus of Acerentomidae

• 1　Abdominal appendage II.III with one seta..................Silvestridia
• -　Abdominal appendage II.III with two setae..................2
• -　Abdominal appendage II.III with three seta..................Acerentulus
• 2　Posterior seta P3 on abdominal tegites II.V or VI anterior to other posterio setae.....3
• -　Posterior seta P3 on abdominal tegites II.VI in the same row as other posterio setae.......10
• 3　Striate band on abdomen VIII developed............4　
• -　Striate band on abdomen VIII reduced............5

  　

• 4　Labial palpus with three or four setae...............Gracilentulus
• -　Labial palpus with a tuft of setae distally................Sugaentulus
• 5　Labial palpus with two or three setae...............6
• -　Labial palpus with a tuft of setae distally................9

  　

• 6　Proximal part of maxillary gland with additiona dilatation...........Kenyentulus
• -　Proximal part of maxillary gland without additiona dilatation...........7
• 7　Foretarsal sensilla b' absent, labial palpus with three setae..............Baculentulus
• -　Foretarsal sensilla b' present,labial palpus with two setae, sensilla on maxillary palpus broad..Neobaculentulus
• 9　Foretarsal sensilla t1 filiform.................Wenyingia 　
• -　Foretarsal sensilla t1 baculiform................Tuxenentulus
• 10　Hind margin of comb on abdomen VIII protruding in a curve backwars.......11
• -　　Hind margin of comb on abdomen VIII almost straight........12
• 11　Foretarsal sensilla t1 filiform................Filientomon
• -　　Foretarsal sensilla t1 baculiform................Yamatentomon
• 12　Abcomen IX.X with dense rows of teeth on hind margin...........Nipponentomon
• -　　Abcomen IX.X without dense rows of teeth on hind margin...........13
• 13　Thorax III with anterior seta Ａ1...............Imadateiella
• -　　Thorax III wihtout anterior seta Ａ1...............14
• 14　Foretarsal sensilla t1 baculiform...............Nosekiella
• -　　Foretarsal sensilla t1 filiform................15
• 15　Foretarsal senseilla d closer to e than c, a' nearer to t1........Verrucoentomon
• -　　Foretarsal senseilla d between c and e, a' nearer to t2......Paracerella

Silvestridia
Foretarsal sensilla b long, reachig γ4, abdominal tergites II-VI with two pairs of anterior setae(A2,5), VII with one pairs(A5).
　S. hutan Imadate, 1965

• 1　Foretarsal sensilla b longer than c, b' at the same level with α4, head with additional setae...........A. kisonis Imadate, 1961
• -　Foretarsal sensilla b subequal to c in length.............................2
• 2　Foretarsal sensilla b reachig e, b' at the same level with α4, head with additional setae .....A. omoi Imadate, 1988
• -　Foretarsal sensilla b not reachig γ3, b' at the same level with ｔ2............3
• 3　head without additional setae................................A. keikoae keikoae Imadate, 1988
• -　head with additional setae................................A. keikoae capillatus Imadate, 1988

• 1　Labial palpus with three setae, posterior seta P3 on abodominal tergite VI anterior to other posaterior setae........G. aokii Imadate, 1982
• -　Labial palpus with four setae, posterior seta P3 on abodominal tergite VI in the same row with other posaterior setae........G. chichibuensis Nakamura, 1995

• 1　P3a on abdominal tergites II-VI absent.....................2
• -　P3a on abdominal tergites II-VI present.....................3
• 2　Foretarsal sensilla b' at the same level with α4, foretarsus 70μm...........K. sakimori (Imadate, 1977)
• -　Foretarsal sensilla b' at the same level with ｔ2, foretarsus 90μm, head with additional setae..........K. monticola Nakamura, 1990
• 3　Foretarsal sensilla b'situated between t2 and α4.....................K. japonicus (Imadate, 1961)
• -　Foretarsal sensilla b' at the same level with ｔ2.....................K. sp.

• 1　Abdominal tergite VII with one pairs of anterior setae(A5)、VIII with two pairs(A3,5)..........B. nitidus (Imadate et Yosii, 1959)
• -　Abdominal tergite VII with three pairs of anterior setae(A2,4,5)、VIII with three pairs(A1,3,5)....2
• 2　Abdominal tergite VI with three pairs of anterior setae(A1,2,5),Foretarsal sensilla b shorther than 2/3 of c......3
• -　Abdominal tergite VI with four pairs of anterior setae(A1,2,4,5),Foretarsal sensilla b longer than c.......5
• 3　P1a on abdominal tergites II-VI absent, foretarsus 100μm........... B. densus (Imadate, 1960)
• -　P1a on abdominal tergites II-VI present, foretarsus shorter than 90μm............4
• 4　Head with additional setae, foretarsal sensilla t3 short..................... B. loxoglenus Yin, 1980
• -　Head without additional setae,ｔ3 relatively long（almost reachign α7）........... B. sakayorii Nakamura, 1995
• 5　P3 on abdominal tergite VI in the same row of other poseterior setae, P3a on abd. terg. V-VII present, canal of maxillary gland ball-shaped.........B. nipponicus Nakamura, 1985
• -　P3 on abdominal tergite VI anterior to other poseterior setae, P3a on abd. terg. V-VII absent, canal of maxillary gland simple..................6
• 6　Foretarsus 74-80 μm.........................B. tosanus (Imadate et Yosii, 1959)
• -　Foretarsus longer than 90μm.........................B. morikawai (Imadate et Yosii, 1956)

• 1　Accessory setae on abdominal tergites II-VI seta-like, longer than 1/4 of P1......2
• -　Accessory setae on abdominal tergites II-VI sensilla-like, shorter than 1/8 of P1.....3
• 2　Abdominal tergites II-VI with five pairs of anterior setae（A1,2,3,4,5).............F. takanawanum (Imadate, 1956)
• -　Abdominal tergites II-VI with six pairs of anterior setae（A1,1',2,3,4,5)...........F. gentaroanum Nakamura, 2001.
• 3　Abdominal tergites II-VI with five pairs of anterior setae（A1,2,3,4,5) , tergal P1a' on IV-V present..........F. kurosai (Imadate, 1964)
• -　Abdominal tergites II-VI with six pairs of anterior setae（A1,1',2,3,4,5) 、tergal P1a' on IV-V absent.........F. lubricum (Imadate, 1956)

• 1　Accessory setae on abdominal tergites II-VI sensilla-like, shorter than 1/8 of P1..........Y. fujisanum Imadate, 1964
• -　Accessory setae on abdominal tergites II-VI seta-like, longer than 1/4 of P1...........2
• 2　Abdominal tergite VII with five pairs of anterior setae（A1,2,3,4,5)..............Y. kunnepchupi Imadate, 1964
• -　Abdominal tergite VII with six pairs of anterior setae（A1,2,3,4,4',5)............ Y. yamato (Imadate et Yosii, 1956)

• 1　P1a on thorax II-III, abdominal tergites I-VI seta-like, longer than 1/4 of P1............2
• -　P1a on thorax II-III, abdominal tergites I-VI senseilla-like, shorter than 1/8 of P1...........3
• 2　P2a on thorax II-III, abdominal tergites I-VI seta-like, longer than 1/4 of P1, head without additional setae..............N. nippon (Yoshii, 1938)
• -　P2a on thorax II-III, abdominal tergites I-VI senseilla-like, shorter than 1/8 of P1...........N. kamui Imadte, 1965
• 3　On thorax II-III, P1a' present between P1a and P2.....................N. uenoi uenoi Imadate et Yosii, 1959
• -　On thorax II-III, P1a' absent.....................4　N. uenoi paucisetosum Imadate, 1965
• 4　P3a on abdominal tergite VII absent, P3a on VI sensilla-like and in the same row of other posterior setae...............Ｂ type
• -　P3a on abdominal tergite VII present, senseilla-like, anterior to other posterior setae. P3a on VI sensilla-like and anterior to other posterior setae....Ｃ type
• -　P3a on abdominal tergite VII present, senseilla-like, anterior to other posterior setae.P3a on VI sensilla-like and in the same row of other posterior setae....Ｄtype
• -　P3a on abdominal tergite VII absent, P2a sensilla-like. P3a on VI sensilla-like and anterior to other posterior set.........Ｅ type
• -　P3a on abdominal tergitesVI-VII absent。P1a adnd P2a on VI seta-like...................Ｆ type

• 1 　P2a on abdominal tergites II-VI seta-like, longer than 1/3 of P1..... I. shiria (Imadate, 1964)
• -　P2a on abdominal tergites II-VI sensilla-like, shorter than 1/6 of P1.....2
• 2　 P2a on abdominal tergite VII seta-like, longer than 1/3 of P1....... I. yosiiana (Imadate, 1961)
• -　P2a on abdominal tergite VII sensilla-like, shorter than 1/6 of P1.......3
• 3　P3a on abdominal tergites II-VII present.............. I. shideiana shideiana (Imadate, 1964)
• -　P3a on abdominal tergites II-VII absent.............. I. shideiana eos (Imadate, 1974)

• 1　P1a,2a on abdominal tergites II-VI seta-like, longer than 1/3 of P1.......V. shirampa (Imadate, 1964)
• -　P1a,2a on abdominal tergites II-VI sensilla-like, shorter than 1/6 of P1......V. kawakatsui (Imadate, 1964)

Eosentomidae　｜　Sinentomidae　｜　Protentomidae　｜　Acerentomidae