http://www.collembola.org/key/mcolombo.htm - Last updated on 2022.11.27 by Frans Janssens
Checklist of the Collembola: Key to the genera of the Collembola from Italy

This key is still under construction. Note that missing figures will be provided as soon as possible. Currently, the key is in the feasibility study phase to find out how to integrate in the checklist in a modular way a key that has been generated with DELTA.

Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Marco Colombo Italy

Rationale

The rationale for taxa used and not used as well as subtaxonomic classification for some taxa is to be provided.

Key

Note that no distinction between subtaxa and taxa is made in the key.

1(0).   Body elongate............................................... 2
        Body globular.............................................. 31
 
2(1).   Protergite absent........................................... 3
        Protergite present......................................... 15
 
3(2).   Body scales absent.......................................... 4
        Body scales present........................................ 10
 
4(3).   Fourth abdominal segment about equal in length to third
          abdominal segment......................................... 5
        Fourth abdominal segment longer then third abdominal segment..
           ......................................................... 9
 
5(4).   Manubrium with at least 8 mid-ventral setae................. 6
        Manubrium with at most 5 mid-ventral setae.................. 8
 
6(5).   Bothriotricha absent........................................ 7
        Bothriotricha present.............................. Isotomurus
 
7(6).   Tenent setae of footcomplex clavate................ Vertagopus
        Tenent setae of footcomplex not clavate............... Desoria
 
8(5).   Fifth abdominal segment fused with sixth abdominal segment....
           ................................................ Hemisotoma
        Fifth abdominal segment not fused with sixth abdominal
          segment.......................................... Proisotoma
 
9(4).   First antennal segment and second antennal segment not
          subdivided....................................... Entomobrya
        First antennal segment and second antennal segment subdivided
          in 2 parts....................................... Orchesella
 
10(3).  Fourth abdominal segment distinctly longer then third
          abdominal segment; third antennal segment not distinctly
          longer then other antennal segments...................... 11
        Fourth abdominal segment shorter then third abdominal segment;
          third antennal segment distinctly longer then other antennal
          segments................................................. 14
 
11(10). Mucro long......................................... Cyphoderus
        Mucro very short........................................... 12
 
12(11). Dorsal scales apically pointed...................... Willowsia
        Dorsal scales apically rounded............................. 13
 
13(12). Eye with 8 ocelli................................ Lepidocyrtus
        Eye with less then 8 ocelli..................... Pseudosinella
 
14(10). Anterior 4 ocelli form a diamond............. Pogonognathellus
        Anterior 4 ocelli form a square..................... Tomocerus
 
15(2).  Furca long, reaching collophore........................ Podura
        Furca short, not reaching collophore....................... 16
 
16(15). Pseudocelli absent......................................... 17
        Pseudocelli present........................................ 29
 
17(16). Mandibula absent............................... Brachystomella
        Mandibula present.......................................... 18
 
18(17). Mandibula with molar teeth................................. 19
        Mandibula without molar teeth.............................. 22
 
19(18). Sixth abdominal segment with 2 anal spines................. 20
        Sixth abdominal segment with 3 anal spines...... Triacanthella
 
20(19). Anal spines distinctly large................... Ceratophysella
        Anal spines indistinct..................................... 21
 
21(20). Eye with 5 ocelli; unguiculus absent.................. Xenylla
        Eye with 8 ocelli; unguiculus present............ Hypogastrura
 
22(18). Antennae not piramid shaped................................ 23
        Antennae piramid shaped........................ Superodontella
 
23(22). Sixth abdominal segment with at least 3 anal spines... Friesea
        Sixth abdominal segment with at most 2 anal spines......... 24
 
24(23). Body with dorsal tubercles................................. 25
        Body without dorsal tubercles.............................. 28
 
25(24). Last abdominal segment bilobed............................. 26
        Last abdominal segment not bilobed.................. Monobella
 
26(25). Sixth abdominal segment not visible in dorsal aspect....... 27
        Sixth abdominal segment visible in dorsal aspect...... Neanura
 
27(26). Body colour blue.................................... Deutonura
        Body colour yellow.................................. Bilobella
 
28(24). Furca absent.......................................... Anurida
        Furca present.................................. Pseudachorutes
 
29(16). Body colour absent......................................... 30
        Body colour present........................... Tetrodontophora
 
30(29). Furcal remnant absent............................ Protaphorura
        Furcal remnant reduced to 2 tubercles............. Kalaphorura
 
31(1).  Antennae longer then head diagonal; eyes present........... 32
        Antennae shorter then head diagonal; eyes absent........... 49
 
32(31). Eyes distinct with up to 8 ocelli.......................... 33
        Eyes indistinct with at most 1 ocellus........... Arrhopalites
 
33(32). Fourth antennal segment distinctly shorter then third antennal
          segment.................................................. 34
        Fourth antennal segment longer then third antennal segment. 36
 
34(33). M seta in transverse row of M'-setae............... Ptenothrix
        M seta not in row of M'-setae.............................. 35
 
35(34). Unguis with tunica................................ Dicyrtomina
        Unguis without tunica............................... Dicyrtoma
 
36(33). Female with sub-anal appendages; male without clasping
          antennae................................................. 37
        Female without sub-anal appendages; male with clasping
          antennae................................................. 47
 
37(36). Fourth antennal segment subdivided......................... 38
        Fourth antennal segment undivided................ Sminthurinus
 
38(37). Footcomplex with 1 sticky macroseta........................ 39
        Footcomplex with more then 1 sticky macrosetae............. 45
 
39(38). Sticky macroseta apically clavate........... Spatulosminthurus
        Sticky macroseta apically pointed.......................... 40
 
40(39). Fourth antennal segment with less then 10 subdivisions; head
          relatively small compared to body; body with curved short
          setae............................................. Lipothrix
        Fourth antennal segment with more then 10 subdivisions; head
          not relatively small compared to body; body not with curved
          short setae.............................................. 41
 
41(40). Unguis inner edge with few teeth........................... 42
        Unguis inner edge with many teeth.......................... 44
 
42(41). Unguis with distinctly large tunica................... Allacma
        Unguis with small apical tunica............................ 43
 
43(42). Aspect not spiky; ocelli C + D as large as other ocelli.......
           ................................................ Sminthurus
        Aspect spiky; ocelli C + D smaller then other ocelli..........
           ................................................. Caprainea
 
44(41). Unguis with cavity.................................. Gisinurus
        Unguis without cavity........................ Disparrhopalites
 
45(38). Unguiculus with distinctly large basal lamella................
           .......................................... Heterosminthurus
        Unguiculus with indistinct basal lamella................... 46
 
46(45). Unguiculus of third leg with subapical filament.. Bourletiella
        Unguiculus of third leg without subapical filament............
           ......................................... Deuterosminthurus
 
47(36). Eyes not very small; female third tibiotarsus with distal
          organ; male clasping organ complex; thorax dorsally without
          pale spot................................................ 48
        Eyes very small; female third tibiotarsus without distal
          organ; male clasping organ simple; thorax dorsally with pale
          spot............................................. Sphaeridia
 
48(47). Female fourth antennal segment subdivided; male posterior
          abdomen without paired array of long setae..... Sminthurides
        Female fourth antennal segment undivided; male posterior
          abdomen with paired array of 6-8 long setae...... Stenacidia
 
49(31). Pigmentation absent; third antennal segment fused with fourth
          antennal segment............................... Megalothorax
        Pigmentation present; third antennal segment not fused with
          fourth antennal segment.................................. 50
 
50(49). Third antennal segment as thick as fourth antennal segment....
           .................................................... Neelus
        Third antennal segment distinctly thicker then fourth antennal
          segment............................................ Neelides

Differential diagnoses

Allacma
Antennae longer then head diagonal. Body globular. Body not with curved short setae. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with 1 sticky macroseta. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Fourth antennal segment with more then 10 subdivisions. Head not relatively small compared to body. Male without clasping antennae. Sticky macroseta apically pointed. Unguis inner edge with few teeth. Unguis with distinctly large tunica.

Anurida
Antennae not piramid shaped. Body elongate. Body without dorsal tubercles. Furca short, not reaching collophore. Furca absent. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with at most 2 anal spines.

Arrhopalites
Antennae longer then head diagonal. Body globular. Eyes indistinct with at most 1 ocellus. Eyes present.

Bilobella
Antennae not piramid shaped. Body elongate. Body with dorsal tubercles. Body colour yellow. Furca short, not reaching collophore. Last abdominal segment bilobed. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment not visible in dorsal aspect. Sixth abdominal segment with at most 2 anal spines.

Bourletiella
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with more then 1 sticky macrosetae. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Male without clasping antennae. Unguiculus of third leg with subapical filament. Unguiculus with indistinct basal lamella.

Brachystomella
Body elongate. Furca short, not reaching collophore. Mandibula absent. Protergite present. Pseudocelli absent.

Caprainea
Antennae longer then head diagonal. Aspect spiky. Body globular. Body not with curved short setae. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with 1 sticky macroseta. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Fourth antennal segment with more then 10 subdivisions. Head not relatively small compared to body. Male without clasping antennae. Ocelli C + D smaller then other ocelli. Sticky macroseta apically pointed. Unguis inner edge with few teeth. Unguis with small apical tunica.

Ceratophysella
Anal spines distinctly large. Body elongate. Furca short, not reaching collophore. Mandibula present. Mandibula with molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with 2 anal spines.

Cyphoderus
Body elongate. Body scales present. Fourth abdominal segment distinctly longer then third abdominal segment. Mucro long. Protergite absent. Third antennal segment not distinctly longer then other antennal segments.

Desoria
Body elongate. Body scales absent. Bothriotricha absent. Fourth abdominal segment about equal in length to third abdominal segment. Manubrium with at least 8 mid-ventral setae. Protergite absent. Tenent setae of footcomplex not clavate.

Deuterosminthurus
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with more then 1 sticky macrosetae. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Male without clasping antennae. Unguiculus of third leg without subapical filament. Unguiculus with indistinct basal lamella.

Deutonura
Antennae not piramid shaped. Body elongate. Body with dorsal tubercles. Body colour blue. Furca short, not reaching collophore. Last abdominal segment bilobed. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment not visible in dorsal aspect. Sixth abdominal segment with at most 2 anal spines.

Dicyrtoma
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Fourth antennal segment distinctly shorter then third antennal segment. M seta not in row of M’-setae. Unguis without tunica.

Dicyrtomina
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Fourth antennal segment distinctly shorter then third antennal segment. M seta not in row of M’-setae. Unguis with tunica.

Disparrhopalites
Antennae longer then head diagonal. Body globular. Body not with curved short setae. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with 1 sticky macroseta. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Fourth antennal segment with more then 10 subdivisions. Head not relatively small compared to body. Male without clasping antennae. Sticky macroseta apically pointed. Unguis without cavity. Unguis inner edge with many teeth.

Entomobrya
Body elongate. Body scales absent. First antennal segment and second antennal segment not subdivided. Fourth abdominal segment longer then third abdominal segment. Protergite absent.

Friesea
Antennae not piramid shaped. Body elongate. Furca short, not reaching collophore. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with at least 3 anal spines.

Gisinurus
Antennae longer then head diagonal. Body globular. Body not with curved short setae. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with 1 sticky macroseta. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Fourth antennal segment with more then 10 subdivisions. Head not relatively small compared to body. Male without clasping antennae. Sticky macroseta apically pointed. Unguis with cavity. Unguis inner edge with many teeth.

Hemisotoma
Body elongate. Body scales absent. Fifth abdominal segment fused with sixth abdominal segment. Fourth abdominal segment about equal in length to third abdominal segment. Manubrium with at most 5 mid-ventral setae. Protergite absent.

Heterosminthurus
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with more then 1 sticky macrosetae. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Male without clasping antennae. Unguiculus with distinctly large basal lamella.

Hypogastrura
Anal spines indistinct. Body elongate. Eye with 8 ocelli. Furca short, not reaching collophore. Mandibula present. Mandibula with molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with 2 anal spines. Unguiculus present.

Isotomurus
Body elongate. Body scales absent. Bothriotricha present. Fourth abdominal segment about equal in length to third abdominal segment. Manubrium with at least 8 mid-ventral setae. Protergite absent.

Kalaphorura
Body elongate. Body colour absent. Furca short, not reaching collophore. Furcal remnant reduced to 2 tubercles. Protergite present. Pseudocelli present.

Lepidocyrtus
Body elongate. Body scales present. Dorsal scales apically rounded. Eye with 8 ocelli. Fourth abdominal segment distinctly longer then third abdominal segment. Mucro very short. Protergite absent. Third antennal segment not distinctly longer then other antennal segments.

Lipothrix
Antennae longer then head diagonal. Body globular. Body with curved short setae. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with 1 sticky macroseta. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Fourth antennal segment with less then 10 subdivisions. Head relatively small compared to body. Male without clasping antennae. Sticky macroseta apically pointed.

Megalothorax
Antennae shorter then head diagonal. Body globular. Eyes absent. Pigmentation absent. Third antennal segment fused with fourth antennal segment.

Monobella
Antennae not piramid shaped. Body elongate. Body with dorsal tubercles. Furca short, not reaching collophore. Last abdominal segment not bilobed. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with at most 2 anal spines.

Neanura
Antennae not piramid shaped. Body elongate. Body with dorsal tubercles. Furca short, not reaching collophore. Last abdominal segment bilobed. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment visible in dorsal aspect. Sixth abdominal segment with at most 2 anal spines.

Neelides
Antennae shorter then head diagonal. Body globular. Eyes absent. Pigmentation present. Third antennal segment not fused with fourth antennal segment. Third antennal segment distinctly thicker then fourth antennal segment.

Neelus
Antennae shorter then head diagonal. Body globular. Eyes absent. Pigmentation present. Third antennal segment not fused with fourth antennal segment. Third antennal segment as thick as fourth antennal segment.

Orchesella
Body elongate. Body scales absent. First antennal segment and second antennal segment subdivided in 2 parts. Fourth abdominal segment longer then third abdominal segment. Protergite absent.

Podura
Body elongate. Furca long, reaching collophore. Protergite present.

Pogonognathellus
Anterior 4 ocelli form a diamond. Body elongate. Body scales present. Fourth abdominal segment shorter then third abdominal segment. Protergite absent. Third antennal segment distinctly longer then other antennal segments.

Proisotoma
Body elongate. Body scales absent. Fifth abdominal segment not fused with sixth abdominal segment. Fourth abdominal segment about equal in length to third abdominal segment. Manubrium with at most 5 mid-ventral setae. Protergite absent.

Protaphorura
Body elongate. Body colour absent. Furca short, not reaching collophore. Furcal remnant absent. Protergite present. Pseudocelli present.

Pseudachorutes
Antennae not piramid shaped. Body elongate. Body without dorsal tubercles. Furca short, not reaching collophore. Furca present. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with at most 2 anal spines.

Pseudosinella
Body elongate. Body scales present. Dorsal scales apically rounded. Eye with less then 8 ocelli. Fourth abdominal segment distinctly longer then third abdominal segment. Mucro very short. Protergite absent. Third antennal segment not distinctly longer then other antennal segments.

Ptenothrix
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Fourth antennal segment distinctly shorter then third antennal segment. M seta in transverse row of M’-setae.

Sminthurides
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Eyes not very small. Female without sub-anal appendages. Female fourth antennal segment subdivided. Female third tibiotarsus with distal organ. Fourth antennal segment longer then third antennal segment. Male with clasping antennae. Male clasping organ complex. Male posterior abdomen without paired array of long setae. Thorax dorsally without pale spot.

Sminthurinus
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Fourth antennal segment longer then third antennal segment. Fourth antennal segment undivided. Male without clasping antennae.

Sminthurus
Antennae longer then head diagonal. Aspect not spiky. Body globular. Body not with curved short setae. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with 1 sticky macroseta. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Fourth antennal segment with more then 10 subdivisions. Head not relatively small compared to body. Male without clasping antennae. Ocelli C + D as large as other ocelli. Sticky macroseta apically pointed. Unguis inner edge with few teeth. Unguis with small apical tunica.

Spatulosminthurus
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Female with sub-anal appendages. Footcomplex with 1 sticky macroseta. Fourth antennal segment longer then third antennal segment. Fourth antennal segment subdivided. Male without clasping antennae. Sticky macroseta apically clavate.

Sphaeridia
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Eyes very small. Female without sub-anal appendages. Female third tibiotarsus without distal organ. Fourth antennal segment longer then third antennal segment. Male with clasping antennae. Male clasping organ simple. Thorax dorsally with pale spot.

Stenacidia
Antennae longer then head diagonal. Body globular. Eyes distinct with up to 8 ocelli. Eyes present. Eyes not very small. Female without sub-anal appendages. Female fourth antennal segment undivided. Female third tibiotarsus with distal organ. Fourth antennal segment longer then third antennal segment. Male with clasping antennae. Male clasping organ complex. Male posterior abdomen with paired array of 6–8 long setae. Thorax dorsally without pale spot.

Superodontella
Antennae piramid shaped. Body elongate. Furca short, not reaching collophore. Mandibula present. Mandibula without molar teeth. Protergite present. Pseudocelli absent.

Tetrodontophora
Body elongate. Body colour present. Furca short, not reaching collophore. Protergite present. Pseudocelli present.

Tomocerus
Anterior 4 ocelli form a square. Body elongate. Body scales present. Fourth abdominal segment shorter then third abdominal segment. Protergite absent. Third antennal segment distinctly longer then other antennal segments.

Triacanthella
Body elongate. Furca short, not reaching collophore. Mandibula present. Mandibula with molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with 3 anal spines.

Vertagopus
Body elongate. Body scales absent. Bothriotricha absent. Fourth abdominal segment about equal in length to third abdominal segment. Manubrium with at least 8 mid-ventral setae. Protergite absent. Tenent setae of footcomplex clavate.

Willowsia
Body elongate. Body scales present. Dorsal scales apically pointed. Fourth abdominal segment distinctly longer then third abdominal segment. Mucro very short. Protergite absent. Third antennal segment not distinctly longer then other antennal segments.

Xenylla
Anal spines indistinct. Body elongate. Eye with 5 ocelli. Furca short, not reaching collophore. Mandibula present. Mandibula with molar teeth. Protergite present. Pseudocelli absent. Sixth abdominal segment with 2 anal spines. Unguiculus absent.


References