Checklist of the Collembola: Key to the species of Hymenaphorura

http://www.collembola.org/key/hymerura.htm - Last updated on 2024.10.31 by Frans Janssens

Checklist of the Collembola: Key to the species of Hymenaphorura

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.

Romuald J. Pomorski, Zoological Institute, Wroclaw University, Sienkiewicza 21, Pl-50-335 Wroclaw, Poland
Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium

Acknowledgements

We would like to thank Dr Mikhail Potapov for providing some modular character illustrations.

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). Distal whorl of setae on tibiotarsi with 11 setae (fig.1b).. 2 Distal whorl of setae on tibiotarsi with 9 setae (fig.1a).. 30

Fig.1.

2(1). Apex of antenna with cauliflower-like papillae; papillae of third antennal segment sense organ short and blunt........ 3 Apex of antenna without papillae; papillae of third antennal segment sense organ elongate.............................. 5

3(2). Fifth abdominal tergum with 2 + 2 lateral macrochaetae only; second and third thoracic terga and first to fourth abdominal terga dorsally without distinct dorsomedial macrochatae......................................... cocklei Fifth abdominal tergum with 5 + 5 lateral macrochaetae at least; second and third thoracic terga and first to fourth abdominal terga dorsally with very distinct macrochatae... 4

4(3). Granulation relatively coarse; on fifth abdominal tergum seta m2 is a macrochaeta; submedial chaetotaxy of fifth abdominal tergum symmetrical..................................... deca Granulation relatively fine; on fifth abdominal tergum seta m2 is not a macrochaeta, difficult to distinguish; submedial chaetotaxy of fifth abdominal tergum usually asymmetrical... ................................................. ridibunda

5(2). Border of postantennal organ groove with 1 border seta...... 6 Border of postantennal organ groove with 2 border setae.... 25

6(5). On first and second abdominal terga seta p2 and p3 of roughly equal length or p2 longer than p3......................... 7 On first and second abdominal terga seta p3 distinctly longer than p2.................................................. 23

7(6). Claw with denticle.......................................... 8 Claw without denticle...................................... 13

8(7). Second external papilla of third antennal segment organ forked.................................................... 9 Second external papilla of third antennal segment organ simple................................................... 10

9(8). First thoracic tergum with 1 + 1 pseudocelli... valdegranulata First thoracic tergum without pseudocelli................ nova

10(8). Base of antenna with 1 + 1 pseudocelli (fig.2a); pseudocellar formula 10/111/11112........................ 11 Base of antenna with 2 + 2 pseudocelli (fig.2b); pseudocellar formula 20/111/111-223............... strasseri

Fig.2.

11(10). Dorsal chaetotaxy distinctly differentiated in macrochaetae and microchaetae; on first to third abdominal terga 6-7 long macrochaetae........................................ liberta Dorsal chaetotaxy poorly differentiated in macrochaetae and microchaetae; on first to third abdominal terga only 1 distinct lateral macrochaetae............................ 12

12(11). Granular area of fifth abdominal tergum with 1 + 1 macrochatae; papillae of third antennal segment sense organ short and plump; postantennal organ with oval, bean-like vesicles........................................... sibirica Granular area of fifth abdominal tergum with 2 + 2 macrochatae; papillae of third antennal segment sense organ not short and plump; postantennal organ with bilobed vesicles............................................ maiteae

13(7). First thoracic tergum with 1 + 1 pseudocelli; groove of postantennal organ very long, prolonged on ventral side of head; postantennal organ located ventro-laterally, invisible from dorsal side.................................... mystica First thoracic tergum without pseudocelli; groove of postantennal organ normal or long; postantennal organ located dorso-laterally usually well visible from dorsal side..................................................... 14

14(13). Second external papilla of third antennal segment organ simple................................................... 15 Second external papilla of third antennal segment organ usually forked........................................... 21

15(14). Granular areas not restricted to small areas around pseudocelli, always with setae........................... 16 Granular areas restricted to small areas around pseudocelli, without setae......................................... gamae

16(15). Dorsal chaetotaxy distinctly differentiated in macrochaetae and microchaetae; on first and second abdominal terga macrochaetae p2 always thicker and usually longer than p1... ........................................................ 17 Dorsal chaetotaxy poorly differentiated in macrochaetae and microchaetae; on first and second abdominal terga only one distinct lateral macrochaeta............................. 19

17(16). On first to third abdominal terga seta m2 absent........... 18 On first to third abdominal terga seta m2 present...... alpina

18(17). Fifth abdominal tergum of adults with p1 setae present; claws with lateral teeth............................. palaearctica Fifth abdominal tergum of adults without p1 setae present; claws without lateral teeth........................ anatolii

19(16). Granulation of fifth abdominal tergum very coarse with cauliflower-like areas pseudocelli surrounded by 11-12 primary granules................................... polonica Granulation of fifth abdominal tergum without cauliflower-like areas.................................................... 20

20(19). Granulation of fifth abdominal tergum coarse; male ventral organ situated above trace of reduced furca, consisting of 16-18 thick weakly curved setae, located closely together; pseudocelli surrounded by 10-11 primary granules............ ............................................ pseudosibirica Granulation of fifth abdominal tergum not coarse; male ventral organ absent; pseudocelli surrounded by 8-9 primary granules.......................................... hispanica

21(14). Adult size 0.8-1.2 mm...................................... 22 Adult size larger than 2 mm........................... teretis

22(21). Granular area of fifth abdominal tergum with one lateral macrochaeta........................................... parva Granular area of fifth abdominal tergum with two macrochaetae. ................................................ aurantiana

23(6). The second external papilla of third antennal segment organ forked.............................................. nicolae The second external papilla of third antennal segment organ simple................................................... 24

24(23). Claw usually with denticle; pseudocellar formula 10/011/11112. ................................................. dentifera Claw without denticle; pseudocellar formula 20/111/11112...... .................................................. alticola

25(5). Base of antenna with 1 + 1 pseudocellus (fig.2a)......... 26 Base of antenna with 2 + 2 pseudocelli (fig.2b)... rafalskii

26(25). First thoracic tergum with 1 + 1 pseudocellus........ alaskana First thoracic tergum without pseudocelli.................. 27

27(26). First thoracic tergum usually with 1 submedian seta; granular area on first abdominal tergum with 7 or 8 setae; granulation not very coarse.............................. 28 First thoracic tergum usually with 2 or 3 submedian setae; granular area on first abdominal tergum with 10 or more setae; granulation very coarse.................... granulata

28(27). Claw with denticle; second lateral papilla in third antennal segment sense organ simple; tibiotarsi with both c3 and b3 setae............................................. sensitiva Claw without denticle; second lateral papilla in third antennal segment sense organ forked; tibiotarsi with b3 setae only............................................... 29

29(28). On fourth abdominal tergum seta p1 located beyond of granular area; on fourth abdominal tergum seta p2 distinguished as macrochaeta....................................... nearctica On fourth abdominal tergum seta p1 located on granular area; on fourth abdominal tergum seta p2 distinguished as micro- or macrochaeta...................................... superba

30(1). Adults size less than 1 mm; second and third thoracic terga seta p2 in forward position (fig.3a)................ reducta Adults size more than 1 mm; second and third thoracic terga seta p2 almost in line with p1 and p3 setae (fig.3b)..... 31

Fig.3.

31(30). Pseudocellar formula 10/111/11112..................... similis Pseudocellar formula 20/111/11112................... improvisa


1(0). Distal whorl of setae on tibiotarsi with 11 setae (fig.1b).. 2 Distal whorl of setae on tibiotarsi with 9 setae (fig.1a).. 30
Fig.1.
2(1). Apex of antenna with cauliflower-like papillae; papillae of third antennal segment sense organ short and blunt........ 3 Apex of antenna without papillae; papillae of third antennal segment sense organ elongate.............................. 5
3(2). Fifth abdominal tergum with 2 + 2 lateral macrochaetae only; second and third thoracic terga and first to fourth abdominal terga dorsally without distinct dorsomedial macrochatae......................................... cocklei Fifth abdominal tergum with 5 + 5 lateral macrochaetae at least; second and third thoracic terga and first to fourth abdominal terga dorsally with very distinct macrochatae... 4
4(3). Granulation relatively coarse; on fifth abdominal tergum seta m2 is a macrochaeta; submedial chaetotaxy of fifth abdominal tergum symmetrical..................................... deca Granulation relatively fine; on fifth abdominal tergum seta m2 is not a macrochaeta, difficult to distinguish; submedial chaetotaxy of fifth abdominal tergum usually asymmetrical... ................................................. ridibunda
5(2). Border of postantennal organ groove with 1 border seta...... 6 Border of postantennal organ groove with 2 border setae.... 25
6(5). On first and second abdominal terga seta p2 and p3 of roughly equal length or p2 longer than p3......................... 7 On first and second abdominal terga seta p3 distinctly longer than p2.................................................. 23
7(6). Claw with denticle.......................................... 8 Claw without denticle...................................... 13
8(7). Second external papilla of third antennal segment organ forked.................................................... 9 Second external papilla of third antennal segment organ simple................................................... 10
9(8). First thoracic tergum with 1 + 1 pseudocelli... valdegranulata First thoracic tergum without pseudocelli................ nova
10(8). Base of antenna with 1 + 1 pseudocelli (fig.2a); pseudocellar formula 10/111/11112........................ 11 Base of antenna with 2 + 2 pseudocelli (fig.2b); pseudocellar formula 20/111/111-223............... strasseri
Fig.2.
11(10). Dorsal chaetotaxy distinctly differentiated in macrochaetae and microchaetae; on first to third abdominal terga 6-7 long macrochaetae........................................ liberta Dorsal chaetotaxy poorly differentiated in macrochaetae and microchaetae; on first to third abdominal terga only 1 distinct lateral macrochaetae............................ 12
12(11). Granular area of fifth abdominal tergum with 1 + 1 macrochatae; papillae of third antennal segment sense organ short and plump; postantennal organ with oval, bean-like vesicles........................................... sibirica Granular area of fifth abdominal tergum with 2 + 2 macrochatae; papillae of third antennal segment sense organ not short and plump; postantennal organ with bilobed vesicles............................................ maiteae
13(7). First thoracic tergum with 1 + 1 pseudocelli; groove of postantennal organ very long, prolonged on ventral side of head; postantennal organ located ventro-laterally, invisible from dorsal side.................................... mystica First thoracic tergum without pseudocelli; groove of postantennal organ normal or long; postantennal organ located dorso-laterally usually well visible from dorsal side..................................................... 14
14(13). Second external papilla of third antennal segment organ simple................................................... 15 Second external papilla of third antennal segment organ usually forked........................................... 21
15(14). Granular areas not restricted to small areas around pseudocelli, always with setae........................... 16 Granular areas restricted to small areas around pseudocelli, without setae......................................... gamae
16(15). Dorsal chaetotaxy distinctly differentiated in macrochaetae and microchaetae; on first and second abdominal terga macrochaetae p2 always thicker and usually longer than p1... ........................................................ 17 Dorsal chaetotaxy poorly differentiated in macrochaetae and microchaetae; on first and second abdominal terga only one distinct lateral macrochaeta............................. 19
17(16). On first to third abdominal terga seta m2 absent........... 18 On first to third abdominal terga seta m2 present...... alpina
18(17). Fifth abdominal tergum of adults with p1 setae present; claws with lateral teeth............................. palaearctica Fifth abdominal tergum of adults without p1 setae present; claws without lateral teeth........................ anatolii
19(16). Granulation of fifth abdominal tergum very coarse with cauliflower-like areas pseudocelli surrounded by 11-12 primary granules................................... polonica Granulation of fifth abdominal tergum without cauliflower-like areas.................................................... 20
20(19). Granulation of fifth abdominal tergum coarse; male ventral organ situated above trace of reduced furca, consisting of 16-18 thick weakly curved setae, located closely together; pseudocelli surrounded by 10-11 primary granules............ ............................................ pseudosibirica Granulation of fifth abdominal tergum not coarse; male ventral organ absent; pseudocelli surrounded by 8-9 primary granules.......................................... hispanica
21(14). Adult size 0.8-1.2 mm...................................... 22 Adult size larger than 2 mm........................... teretis
22(21). Granular area of fifth abdominal tergum with one lateral macrochaeta........................................... parva Granular area of fifth abdominal tergum with two macrochaetae. ................................................ aurantiana
23(6). The second external papilla of third antennal segment organ forked.............................................. nicolae The second external papilla of third antennal segment organ simple................................................... 24
24(23). Claw usually with denticle; pseudocellar formula 10/011/11112. ................................................. dentifera Claw without denticle; pseudocellar formula 20/111/11112...... .................................................. alticola
25(5). Base of antenna with 1 + 1 pseudocellus (fig.2a)......... 26 Base of antenna with 2 + 2 pseudocelli (fig.2b)... rafalskii
26(25). First thoracic tergum with 1 + 1 pseudocellus........ alaskana First thoracic tergum without pseudocelli.................. 27
27(26). First thoracic tergum usually with 1 submedian seta; granular area on first abdominal tergum with 7 or 8 setae; granulation not very coarse.............................. 28 First thoracic tergum usually with 2 or 3 submedian setae; granular area on first abdominal tergum with 10 or more setae; granulation very coarse.................... granulata
28(27). Claw with denticle; second lateral papilla in third antennal segment sense organ simple; tibiotarsi with both c3 and b3 setae............................................. sensitiva Claw without denticle; second lateral papilla in third antennal segment sense organ forked; tibiotarsi with b3 setae only............................................... 29
29(28). On fourth abdominal tergum seta p1 located beyond of granular area; on fourth abdominal tergum seta p2 distinguished as macrochaeta....................................... nearctica On fourth abdominal tergum seta p1 located on granular area; on fourth abdominal tergum seta p2 distinguished as micro- or macrochaeta...................................... superba
30(1). Adults size less than 1 mm; second and third thoracic terga seta p2 in forward position (fig.3a)................ reducta Adults size more than 1 mm; second and third thoracic terga seta p2 almost in line with p1 and p3 setae (fig.3b)..... 31
Fig.3.
31(30). Pseudocellar formula 10/111/11112..................... similis Pseudocellar formula 20/111/11112................... improvisa

http://www.collembola.org/key/hymerura.htm - Last updated on 2024.10.31 by Frans Janssens

Acknowledgements

Rationale

Key

References