http://www.collembola.org/key/subitoma.htm - Last updated on 2009.12.22 by Frans Janssens
Checklist of the Collembola: Key to the species of Subisotoma

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.

Mikhail Potapov, Moscow State Pedagogical University, Moscow 129164, Russia
Anatoly Babenko, Institute of Ecology and Evolution RAN, Moscow 119071, Russia
Arne Fjellberg, Mageroveien 168, N-3145 Tjome, Norway
Penelope Greenslade, Research School of Biology, Australian National University, Australian Capital Territory 0200, Australia
Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium

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).   Microsensilla 10/101; third thoracic segment with ventral
          chaetae; tibiotarsal tenent chaetae long and clavate...... 2
        Microsensilla fewer than 10/101; third thoracic segment
          without ventral chaetae; tibiotarsal tenent chaetae hardly
          differentiated........................................... 10
 

2(1).   Ocelli 6 + 6, ocellus C absent, H absent, but G present
          (fig.1a)........................................ guzeriplica
        Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b)......... 3

Fig.1.
   
3(2).   Tergal sensilla arranged in groups (fig.2).... multisensillata
        Tergal sensilla normally arranged (fig.3)................... 4

Fig.2.
  

Fig.3.
   
4(3).   Terga of second and third thoracic segment with 3
          macrosensilla............................................. 5
        Terga of second and third thoracic segment with 4
          macrosensilla, complete formula 44/33334 (fig.4).... pusilla

Fig.4.
   
5(4).   Tergum of first abdominal segment with 2 macrosensilla...... 6
        Tergum of first abdominal segment with 3 macrosensilla, terga
          of first to fourth abdominal segment with 3, 3, 3, 3
          macrosensilla, complete formula 33/33334 (fig.5). homonomica

Fig.5.
   
6(5).   Tergum of third abdominal segment with 2 macrosensilla, terga
          of first to fourth abdominal segment with 2, 2, 2, 2
          macrosensilla, complete formula 33/22224 (fig.6).......... 7
        Tergum of third abdominal segment with 3 macrosensilla...... 8

Fig.6.
   
7(6).   Third antennal segment with 3-4 additional sensilla (fig.7a);
          third thoracic segment with 2 + 2 ventral chaetae (fig.8b).
           .............................................. bisensillata
        Third antennal segment with one additional sensillum
          (fig.7b); third thoracic segment with 1 + 1 ventral chaetae
          (fig.8a)............................................ tenuis

Fig.7.
  

Fig.8.
   
8(6).   Tergum of fourth abdominal segment with 6-7 macrosensilla,
          terga of first to fourth abdominal segment with 2, 2-3, 3,
          6-7 macrosensilla, complete formula 33/22-336-75-7 (fig.9)..
           ............................................ posteriomollis
        Tergum of fourth abdominal segment with less than 6
          macrosensilla............................................. 9

Fig.9.
   
9(8).   Terga of first to fourth abdominal segment with 2, 2-3, 3, 3
          macrosensilla, complete formula 33/22-3334 (fig.10); third
          antennal segment with 2-4 additional sensilla (fig.11)......
           ................................................. pomorskii
        Terga of first to fourth abdominal segment with 2, 3, 3, 4
          macrosensilla, complete formula 33/23344 (fig.12); third
          antennal segment with 4-9 additional sensilla...............
           .......................................... quadrisensillata

Fig.10.
  

Fig.11.
  

Fig.12.
   
10(1).  Microsensilla on third abdominal segment absent (fig.13b);
          cuticle granulation fine................................. 11
        Microsensilla on third abdominal segment present (fig.13a),
          complete formula 10/001; cuticle with coarse granulation
          (fig.14)........................................... asiatica

Fig.13.
  

Fig.14.
   
11(10). Basal microsensilla on third antennal segment absent
          (fig.15a); microsensilla on first abdominal segment absent,
          complete formula 10/000; dens without anterior chaeta. cruda
        Basal microsensilla on third antennal segment present
          (fig.15b); microsensilla on first abdominal segment present
          (fig.16), complete formula 10/100; dens with anterior
          chaeta............................................. erratica

Fig.15.
  

Fig.16.
  

Differential diagnoses

asiatica
Cuticle with coarse granulation (fig.14). Microsensilla fewer than 10/101. Microsensilla on third abdominal segment present (fig.13a), complete formula 10/001. Third thoracic segment without ventral chaetae. Tibiotarsal tenent chaetae hardly differentiated.

bisensillata
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Terga of second and third thoracic segment with 3 macrosensilla. Tergal sensilla normally arranged (fig.3). Tergum of first abdominal segment with 2 macrosensilla. Tergum of third abdominal segment with 2 macrosensilla, terga of first to fourth abdominal segment with 2, 2, 2, 2 macrosensilla, complete formula 33/22224 (fig.6). Third antennal segment with fig.3–4 additional sensilla (fig.7a). Third thoracic segment with ventral chaetae. Third thoracic segment with 2 + 2 ventral chaetae (fig.8b). Tibiotarsal tenent chaetae long and clavate.

cruda
Basal microsensilla on third antennal segment absent (fig.15a). Cuticle granulation fine. Dens without anterior chaeta. Microsensilla fewer than 10/101. Microsensilla on first abdominal segment absent, complete formula 10/000. Microsensilla on third abdominal segment absent (fig.13b). Third thoracic segment without ventral chaetae. Tibiotarsal tenent chaetae hardly differentiated.

erratica
Basal microsensilla on third antennal segment present (fig.15b). Cuticle granulation fine. Dens with anterior chaeta. Microsensilla fewer than 10/101. Microsensilla on first abdominal segment present (fig.16), complete formula 10/100. Microsensilla on third abdominal segment absent (fig.13b). Third thoracic segment without ventral chaetae. Tibiotarsal tenent chaetae hardly differentiated.

guzeriplica
Microsensilla 10/101. Ocelli 6 + 6, ocellus C absent, H absent, but G present (fig.1a). Third thoracic segment with ventral chaetae. Tibiotarsal tenent chaetae long and clavate.

homonomica
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Terga of second and third thoracic segment with 3 macrosensilla. Tergal sensilla normally arranged (fig.3). Tergum of first abdominal segment with 3 macrosensilla, terga of first to fourth abdominal segment with 3, 3, 3, 3 macrosensilla, complete formula 33/33334 (fig.5). Third thoracic segment with ventral chaetae. Tibiotarsal tenent chaetae long and clavate.

multisensillata
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Tergal sensilla arranged in groups (fig.2). Third thoracic segment with ventral chaetae. Tibiotarsal tenent chaetae long and clavate.

pomorskii
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Terga of first to fourth abdominal segment with 2, fig.2–3, 3, 3 macrosensilla, complete formula 33/22–3334 (fig.10). Terga of second and third thoracic segment with 3 macrosensilla. Tergal sensilla normally arranged (fig.3). Tergum of first abdominal segment with 2 macrosensilla. Tergum of fourth abdominal segment with less than 6 macrosensilla. Tergum of third abdominal segment with 3 macrosensilla. Third antennal segment with 2–4 additional sensilla (fig.11). Third thoracic segment with ventral chaetae. Tibiotarsal tenent chaetae long and clavate.

posteriomollis
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Terga of second and third thoracic segment with 3 macrosensilla. Tergal sensilla normally arranged (fig.3). Tergum of first abdominal segment with 2 macrosensilla. Tergum of fourth abdominal segment with 6–7 macrosensilla, terga of first to fourth abdominal segment with 2, 2–3, 3, 6–7 macrosensilla, complete formula fig./22–336–75–7 (fig.9). Tergum of third abdominal segment with 3 macrosensilla. Third thoracic segment with ventral chaetae. Tibiotarsal tenent chaetae long and clavate.

pusilla
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Terga of second and third thoracic segment with 4 macrosensilla, complete formula 44/33334 (fig.4). Tergal sensilla normally arranged (fig.3). Third thoracic segment with ventral chaetae. Tibiotarsal tenent chaetae long and clavate.

quadrisensillata
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Terga of first to fourth abdominal segment with fig.2, 3, 3, 4 macrosensilla, complete formula 33/23344 (fig.12). Terga of second and third thoracic segment with 3 macrosensilla. Tergal sensilla normally arranged (fig.3). Tergum of first abdominal segment with 2 macrosensilla. Tergum of fourth abdominal segment with less than 6 macrosensilla. Tergum of third abdominal segment with 3 macrosensilla. Third antennal segment with 4–9 additional sensilla. Third thoracic segment with ventral chaetae. Tibiotarsal tenent chaetae long and clavate.

tenuis
Microsensilla 10/101. Ocelli 8 + 8, ocellus G smaller, H smaller (fig.1b). Terga of second and third thoracic segment with 3 macrosensilla. Tergal sensilla normally arranged (fig.3). Tergum of first abdominal segment with 2 macrosensilla. Tergum of third abdominal segment with 2 macrosensilla, terga of first to fourth abdominal segment with 2, 2, 2, 2 macrosensilla, complete formula 33/22224 (fig.6). Third antennal segment with one additional sensillum (fig.7b). Third thoracic segment with ventral chaetae. Third thoracic segment with 1 + 1 ventral chaetae (fig.8a). Tibiotarsal tenent chaetae long and clavate.

References