http://www.collembola.org/key/hymerura.htm - Last updated on 2024.05.31 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



References