1	Meso- and metanotum with tracheal system and spiracles	2
–	Spiracles absent	13
2	Pectinated structures on the abdomen present; pseudoculi transversally striated; abdominal appendages I two-segmented, with terminal vesicle and four setae, abdominal appendages II and III unisegmented with two setae	Sinentomon (65)
–	Abdominal pectinated structures absent; not striated pseudoculi; abdominal appendages I–III two-segmented, each with five setae	3
3	Foretarsal sensillum e absent	4
–	Foretarsal sensillum e present	9
4	Tergites X or XI with large spines	Anisentomon (72)
–	Tergites X–XI without spines	5
5	Foretarsal sensillum g long, spatulate	6
–	Foretarsal sensillum g not long and spatulate	8
6	Tergite VIII with 6/8 setae (Pc absent)	Neanisentomon (73)
–	Tergite VIII with 6/9 setae (Pc present)	7
7	Foretarsal sensillum f1 setiform	Paranisentomon (74)
–	Foretarsal sensillum f1 spindle-shaped	Pseudanisentomon (75)
8	Foretarsal sensillum b1’ absent	Osientomon (67)
–	Foretarsal sensillum b1’ present	Isoentomon (66 – part)
9	Foretarsal sensillum e spatulate (or clavate)	10
–	Foretarsal sensillum e not spatulate	12
10	Labrum long and narrow (rostrum); stylet-shaped mandibles	Styletoentomon (71)
–	Labrum and mandibles of normal shape	11
11	Pseudoculi with a large triangular prolongation on the anterior margin	Zhongguohentomon (69)
–	Pseudoculi lens-like	Eosentomon (70)
12	Seta P1a on tergites I–VI longer than P1	Isoentomon (66 – part)
–	Seta P1a on tergites I–VI shorter than P1	Madagascarentomon (68)
13	Three pairs of two-segmented abdominal appendages	14
–	Abdominal appendages III uni-segmented	17
14	Abdominal appendages with five setae; abdominal pectinated structures absent	Antelientomon (76)
–	Abdominal appendages with four setae	15
15	Foretarsal sensilla b’ and c’ absent	16
–	Foretarsal sensilla b’ and c’ present	Hesperentomon (1)
16	Canal of maxillary glands with heart-shaped calyx with verrucose appendices and a proximal dilation; pseudoculi with a large triangular prolongation in the proximal part	Hinomotentomon (4)
–	Canal of maxillary glands simple, ending with a long sac- or sausage-like dilation; pseudoculi circular without prolongation	Fujientomon (64)
17	Abdominal appendages II two-segmented	18
–	Abdominal appendages II uni-segmented	23
18	Foretarsi with an additional sensillum c”; pseudoculi “open” posteriorly	Ionescuellum (2)
–	Foretarsi without additional sensillum c”; pseudoculi never “open” posteriorly	19
19	Foretarsal sensilla b’ and c’ missing, t1 always present (setiform); abdominal appendages III with two or three setae	20
–	Foretarsal sensilla t1 and c often missing, all the other sensilla always present; abdominal appendages III always with two setae	22
20	Pseudoculi with a short lever; sternites IV–V without Pc seta	Neocondeellum (6)
–	Pseudoculi circular without lever; sternites IV–V with Pc seta	21
21	Abdominal appendages III with two setae	Paracondeellum (7)
–	Abdominal appendages III with three setae	Condeellum (5)
22	Metanotum with only one pair of A-setae (A2); t1 usually and c always present; distinct teeth on comb on abdominal segment VIII	Proturentomon (9)
–	Metanotum with two pairs of A-setae (A2, A4); t1 always and c sometimes missing; teeth on comb on abdominal segment VIII indistinct or missing	Protentomon (8)
23	Sternite VIII with 2/4 setae	Huhentomon (3)
–	Sternite VIII never with 2/4 setae (normally with 4/0 or 4/2 setae)	24
24	Calyx of maxillary glands granulated or racemose and/or with racemose/granulated appendices, abdominal appendages II–III each with two setae	25
–	Calyx of maxillary glands not as above (when weakly verrucose, abdominal appendages II–III have three setae)	40
25	Metanotum with two pairs of A-setae	26
–	Metanotum with three or four pairs of A-setae	27
26	Labial palps reduced, with one broad sensillum and three setae	Chosonentulus (21)
–	Labial palps not reduced with a terminal tuft of setae and one lateral sensillum	Alaskaentomon (50)
27	Metanotum with three pairs of A-setae	28
–	Metanotum with four pairs of A-setae	37
28	Foretarsal sensillum t1 filiform	29
–	Foretarsal sensillum t1 baculiform or claviform	34
29	Pronotum with three pairs of setae; maxillary glands with large vesicle bearing finger-like papillae	Callientomon (51)
–	Pronotum with two pairs of setae; maxillary glands without papillae	30
30	Calyx of maxillary glands with small granulated appendices; foretarsal sensillum t3 globular	Nienna (53)
–	Calyx of maxillary glands not as the one of Nienna; foretarsal sensillum t3 foliate	31
31	Foretarsal seta β1 sensilliform	Noldo (55)
–	Foretarsal seta β1 setiform	32
32	Bases of sensilla d and a’ level with base of sensillum t2 on foretarsi	Paracerella (57)
–	One or both of the bases of sensilla d and a’ not at the same level of sensillum t2 on foretarsi	33
33	Bases of sensilla d and a’ proximal to the base of t2 on foretarsi	Acerella (63)
–	One or both of the bases of sensilla d and a’ distal to base of sensillum t2 on foretarsi	Verrucoentomon (58)
34	Foretarsal sensillum t1 baculiform	Nosekiella (56)
–	Foretarsal sensillum t1 claviform	35
35	Maxillary glands with smooth globular vesicle near calyx; foretarsal sensillum d central between sensilla c and e; seta 1 on sternites VIII and X short, one-third length of seta 2	Nosekientomon (61)
–	Maxillary glands without vesicle near calyx; foretarsal sensillum d close to e; seta 1 on sternite VIII longer than half the length of seta 2	36
36	Foretarsal sensillum a’ distal to t2	Yavanna (62)
–	Foretarsal sensillum a’ nearly at the same level of t1 (proximal to t2)	Nanshanentulus (59)
37	Foretarsal sensillum t1 baculiform; maxillary glands with large vesicle near calyx	Vesiculentomon (60)
–	Foretarsal sensillum t1 filiform (setiform or spindle-shaped); maxillary glands without vesicle near calyx	38
38	Sternite VIII with 4/2 setae	Nipponentomon (54)
–	Sternite VIII with 4/0 setae	39
39	Lateral apical and subapical setae on abdominal appendages II–III of equal length (in one case only the subapical seta present); comb VIII with the posterior margin rounded and protruding backward	Filientomon (40)
–	Lateral apical seta on abdominal appendages II–III more than half the length of the subapical; posterior margin of comb VIII not protruding backward	Imadateiella (52)
40	Abdominal appendages II–III each with one seta (rarely also a delicate median apical seta is present)	41
–	Abdominal appendages II–III each with two or three setae	45
41	Labial palps not reduced	Acerentomon (39 – part)
–	Labial palps reduced	42
42	Striate band well developed	Tuxenidia (35 – part)
–	Striate band reduced	43
43	Canal of maxillary glands with heart-shaped calyx and three lobes on the distal part near calyx, proximally deeply bipartite	Madagascaridia (25)
–	Canal of maxillary glands without lobes near calyx	44
44	Canal of maxillary glands with heart-shaped calyx, the short proximal part with a distinct lateral protuberance and terminating with a “head of femur”-shaped dilation; foretarsal sensillum a’ sword-shaped	Bolivaridia (18)
–	Canal of maxillary glands simple with heart-shaped calyx, more or less bipartite in the proximal part; foretarsal sensillum a’ shaped as an old Roman vase	Silvestridia (33)
45	Abdominal appendages II–III each with three setae	46
–	Abdominal appendages II–III each with two setae	52
46	Striate band reduced	47
–	Striate band not reduced	49
47	Foretarsal sensillum t3 knob-shaped	Andinentulus (14)
–	Foretarsal sensillum t3 not knob-shaped	48
48	Foretarsal sensillum t3 relatively long, cylindrical	Brasilidia (20)
–	Foretarsal sensillum t3 willow leaf-shaped	Fjellbergella (41)
49	Foretarsal sensillum t3 very long (largely passing base of seta α7), cylindrical	Najtentulus (27)
–	Foretarsal sensillum t3 not cylindrical	50
50	Foretarsal sensillum t3 lancet-like or finger-like and tapering on apex; canal of maxillary glands with proximal part ending with a row of small globules which increase in size and end with two globules placed beside each other	Acerentuloides (10)
–	Foretarsal sensillum t3 not lancet-like or finger-like; proximal end of canal of maxillary glands without globules	51
51	Foretarsal sensillum t3 cylindrical and rounded on apex or small knob-like; sternite VIII with 4/0 setae	Australentulus (15)
–	Foretarsal sensillum t3 willow leaf-shaped; sternite VIII with 4/2 setae	Acerentulus (11)
52	Canal of maxillary glands with two or three beady widenings	Kenyentulus (24)
–	Canal of maxillary glands without beady widenings	53
53	Labial palps not reduced, with branched tuft of setae	54
–	Labial palps reduced, without tuft of setae (or just a one-branched terminal tuft of setae)	61
54	Mesonotum with three pairs of A-setae and metanotum with four pairs of A-setae; sternites with five or more A-setae; seta P3 on tergites II–VI in line with other P-setae; striate band well developed	55
–	Mesonotum and metanotum with two pairs of A-setae; sternites with three A-setae; seta P3 on tergites II–VI slightly anterior to P-setae row; striate band well developed or reduced	57
55	Foretarsal sensillum t1 baculiform	Yamatentomon (47)
–	Foretarsal sensillum t1 claviform	56
56	Foretarsal sensillum a’ close to t1	Orinentomon (43)
–	Foretarsal sensillum a’ distal to t2 and close to c’	Acerentomon (39 – part)
57	Striate band well developed	58
–	Striate band reduced	60
58	Foretarsal sensillum t1 filiform; b’ missing	Huashanentulus (42)
–	Foretarsal sensillum t1 claviform	59
59	Foretarsal sensillum t3 long parallel-sided; b’ present	Maderentulus (26)
–	Foretarsal sensillum t3 short lanceolate; b’ missing	Sugaentulus (44)
60	Foretarsal sensillum t1 claviform; a’ close to t2	Tuxenentulus (45)
–	Foretarsal sensillum t1 filiform; a’ close to t1	Wenyingia (46)
61	Foretarsal sensillum t1 baculiform	62
–	Foretarsal sensillum t1 claviform	67
62	Foretarsal sensillum t3 long, nearly cylindrical	Tuxenidia (35 – part)
–	Foretarsal sensillum t3 not as above	63
63	Head in profile has a prominent “front”	Yinentulus (37)
–	Head without “front”	64
64	Maxillary palps with one setiform and one torch light-shaped sensillum; foretarsal sensillum b’ always present	Neobaculentulus (28)
–	Maxillary palps with both sensilliform or setiform sensilla; foretarsal sensillum b’ sometimes missing	65
65	Canal of maxillary glands with excrescences	Notentulus (29)
–	Canal of maxillary glands simple, without excrescences	66
66	Sternite VIII with 4/2 setae	Yichunentulus (48)
–	Sternite VIII with 4/0 setae	Baculentulus (16)
67	Striate band reduced	68
–	Striate band well developed or partly reduced (with visible parallel striae)	73
68	Foretarsal sensillum b’ present	69
–	Foretarsal sensillum b’ absent	71
69	Abdominal appendages II–III each with a long subapical and a very short median apical seta (< 1/3rd the length of subapical one)	Berberentulus (17 – part)
	Abdominal appendages II–III each with a lateral apical seta more than 1/3rd the length of the subapical one	70
70	Labial palps reduced, with three setae and no sensilla	Liaoxientulus (49)
–	Labial palps reduced with one sensillum and three setae.	Amphientulus (13)
71	Foretarsal sensillum t3 very long awl-shaped	Amazonentulus (12)
–	Foretarsal sensillum t3 not long and shaped as a willow leaf, or a small jar or as a knob	72
72	Proximal part of the canal of maxillary glands tripartite; abdominal appendages II–III each with the median apical seta half the length of the subapical one	Polyadenum (31)
–	Canal of maxillary glands simple, with heart-shaped calyx and “single” proximal part; abdominal appendages II–III each with the median apical seta less than 1/3rd the length of subapical one	Berberentulus (17 – part)
73	Striate band partly reduced (the striae may be seen more or less distinctly, but never as distinct) with hook-shaped design; lateral apical seta on abdominal appendages II–III more than half as long as the subapical; sternite VIII with 4/2 setae	Tasmanentulus (34)
–	Striate band well developed, without hook-shaped design (except in Proacerella reducta Bernard)	74
74	Abdominal appendages II–III each with lateral apical seta more than half as long as the subapical one; labial palps with four setae and a sensillum	Proacerella (32)
–	Abdominal appendages II–III each with median apical seta less than half as long as the subapical one; labial palps with two or three setae and a sensillum	75
75	Labial palps with two setae and a sensillum; canal of maxillary glands with smooth and simple kidney bean-shaped calyx, the end of proximal canal slightly tripartite	Zangentulus (38)
–	Labial palps with three setae and a sensillum; calyx of maxillary glands not kidney bean-shaped	76
76	Foretarsal sensillum t3 small and knob-like (except in G. sarmaticus Shrubovych and Szeptycki where t3 is large)	Gracilentulus (23)
–	Foretarsal sensillum t3 long, not knob-like	77
77	Foretarsal sensillum b very long reaching or passing the empodium	78
–	Foretarsal sensillum b not so long	79
78	Prosternum without seta A2	Podolinella (30)
–	Prosternum with seta A2	Vindobonella (36)
79	Canal of maxillary glands with heart-shaped calyx	Brasilentulus (19)
–	Canal of maxillary glands with long and slender calyx	Delamarentulus (22)