http://www.collembola.org/key/fknl.pdf - Last updated on 2009.07.03 by Frans Janssens
Checklist of the Collembola:
Pictorial key to common surface dwelling species of Collembola from the Netherlands

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
Ab H. Baas European Invertebrate Survey - Nederland, Postbus 9517, 2300 RA Leiden, Nederland

Preamble

This experimental and macrophotographically illustrated key is intended to key out the most common surface dwelling species of Collembola from the region of Hardenberg, the Netherlands, based on habitus inspection of alive specimens in the field using at most a magnification of 5 times.

All illustrations courtesy of macrophotographer Ab H. Baas.

Key

    
1(0).   Body form elongate (fig.1a)................................ 2
        Body form subglobular (fig.1b)............................ 23

Fig.1.
   
2(1).   Body iridescent, covered with scales (fig.2)............... 3
        Body not iridescent, not covered with scales................ 6

Fig.2.
   
3(2).   Apical antennomere about equal to subapical antennomere
          (fig.3); antenna with 5 segments (fig.4): basal
          antennomere subdivided.................... Heteromurus major
        Apical antennomere much shorter then subapical antennomere;
          antenna with 4 segments................................... 4

Fig.3.
  

Fig.4.
   
4(3).   Third antennal segment subcylindric (fig.5)................ 5
        Third antennal segment tapering (fig.6)......................
           ............................... Pogonognathellus flavescens

Fig.5.
  

Fig.6.
   
5(4).   Body dark purplish with transversal goldish bands at
          intersegmental margins (fig.7).......... Tomocerus vulgaris
        Body uniform bluish-grey (fig.8)............. Tomocerus minor

Fig.7.
  

Fig.8.
   
6(2).   Head blackish............................................... 7
        Head not blackish........................................... 8
 

7(6).   Abdomen with distinct whitish transversal band (fig.9),
          (fig.10)............................ Orchesella cincta adult
        Abdomen without whitish transversal band (fig.11).............
           .............................. Isotoma viridis var violacea

Fig.9.
  

Fig.10.
  

Fig.11.
   
8(6).   Body with long dorsal setae................................. 9
        Body without long dorsal setae............................. 22
 

9(8).   Body with few long dorsal setae............................ 10
        Body with many long dorsal setae........................... 15
 

10(9).  Body background colour not uniform......................... 11
        Body background colour uniform............................. 13
 

11(10). Body pigmentation in longitudinal pattern.................. 12
        Body pigmentation in transversal pattern (fig.12).............
           .............................. Isotoma viridis var annulata

Fig.12.
   
12(11). Lateral thoracic pigmentation distinctly patchy; middorsal
          segmental pigmentation in the shape of a crown (fig.13);
          tibiotarsi distinctly differently coloured than femora......
           ...................................... Isotomurus maculatus
        Lateral thoracic pigmentation indistinct; middorsal segmental
          pigmentation in the shape of a solid line (fig.14);
          tibiotarsi and femora equally coloured. Isotomurus palustris

Fig.13.
  

Fig.14.
   
13(10). Body background colour greenish (fig.15)....... Isotoma viridis
        Body background colour not greenish........................ 14

Fig.15.
   
14(13). Body background colour brownish with pale random dot pattern
          (fig.16)......................... Isotoma anglicana juvenile
        Body background colour dark violet with distinct pale dot
          pattern lateral on abdomen (fig.17). Isotoma anglicana adult

Fig.16.
  

Fig.17.
   
15(9).  Antenna with 4 segments; trunk with one abdominal segment
          distinctly longer than the others (fig.18)............... 16
        Antenna with 6 segments (fig.19): basal two antennomeres
          subdivided; trunk with subequal abdominal segments....... 20

Fig.18.
  

Fig.19.
   
16(15). Thoracic dorsal pigmentation absent........................ 17
        Thoracic dorsal pigmentation present....................... 18
 

17(16). Dorsal pigmentation of the second and third abdominal segment
          in distinct transversal bands (fig.20)......................
           ......................... Entomobrya nivalis forma dorsalis
        Dorsal pigmentation of the second and third abdominal segment
          in indistinct transversal patches (fig.18), (fig.21)........
           ....................................... Entomobrya nicoleti

Fig.20.
  

Fig.21.
   
18(16). Thoracic dorsal pigmentation in longitudinal bands (fig.22)....
           ....................................... Entomobrya muscorum
        Thoracic dorsal pigmentation in transversal bands.......... 19

Fig.22.
   
19(18). Dorsal abdominal pigmentation in irregular transversal bands
          (fig.23)........................... Entomobrya multifasciata
        Dorsal abdominal pigmentation in the shape of a capital U
          (fig.24).................................. Entomobrya nivalis

Fig.23.
  

Fig.24.
   
20(15). Body pigmentation pattern in complex pattern of patches
          (fig.25).................................. Orchesella villosa
        Body pigmentation pattern in distinct bands................ 21

Fig.25.
   
21(20). Body pigmentation in longitudinal bands (fig.26)...............
           ..................................... Orchesella flavescens
        Body pigmentation in transversal bands (fig.27)...............
           ................................ Orchesella cincta juvenile

Fig.26.
  

Fig.27.
   
22(8).  Body colour greenish (fig.28)................ Desoria olivacea
        Body colour greyish (fig.29).................. Desoria tigrina

Fig.28.
  

Fig.29.
   
23(1).  Body background colour brownish............................ 24
        Body background colour yellowish with patchy brown
          pigmentation............................................. 26
 

24(23). Body texture dull.......................................... 25
        Body texture glossy (fig.30).................... Allacma fusca

Fig.30.
   
25(24). Dorsum uniformly coloured (fig.31)............ Dicyrtoma fusca
        Dorsum with middorsal yellow longitudinal stripe (fig.32).....
           ........................................ Dicyrtomina ornata 1

Fig.31.
  

Fig.32.
   
26(23). Dorsal posterior patch multi barred cross shaped (fig.33);
          second antennomere colour distinctly more pale then that of
          third antennomere, especially at the joint (fig.34b)........
           ..................................... Dicyrtomina saundersi
        Dorsal posterior patch solid rectangular (fig.35); second
          antennomere colour gradually fading into that of third
          antennomere (fig.34a).................... Dicyrtomina ornata

Fig.33.
  

Fig.34.
  

Fig.35.
  

Endnotes

1 Very dark colour form lacking the typical patchy pigmentation.

Differential diagnoses

Allacma fusca
Body background colour brownish. Body form subglobular (fig.1b). Body texture glossy (fig.30).

Desoria olivacea
Body not iridescent, not covered with scales. Body without long dorsal setae. Body colour greenish (fig.28). Body form elongate (fig.1a). Head not blackish.

Desoria tigrina
Body not iridescent, not covered with scales. Body without long dorsal setae. Body colour greyish (fig.29). Body form elongate (fig.1a). Head not blackish.

Dicyrtoma fusca
Body background colour brownish. Body form subglobular (fig.1b). Body texture dull. Dorsum uniformly coloured (fig.31).

Dicyrtomina ornata
Body background colour yellowish with patchy brown pigmentation. Body form subglobular (fig.1b). Dorsal posterior patch solid rectangular (fig.35). Second antennomere colour gradually fading into that of third antennomere (fig.34a).

Dicyrtomina ornata 1
Body background colour brownish. Body form subglobular (fig.1b). Body texture dull. Dorsum with middorsal yellow longitudinal stripe (fig.32).

Dicyrtomina saundersi
Body background colour yellowish with patchy brown pigmentation. Body form subglobular (fig.1b). Dorsal posterior patch multi barred cross shaped (fig.33). Second antennomere colour distinctly more pale then that of third antennomere, especially at the joint (fig.34b).

Entomobrya multifasciata
Antenna with 4 segments. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body with many long dorsal setae. Dorsal abdominal pigmentation in irregular transversal bands (fig.23). Head not blackish. Thoracic dorsal pigmentation present. Thoracic dorsal pigmentation in transversal bands. Trunk with one abdominal segment distinctly longer than the others (fig.18).

Entomobrya muscorum
Antenna with 4 segments. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body with many long dorsal setae. Head not blackish. Thoracic dorsal pigmentation present. Thoracic dorsal pigmentation in longitudinal bands (fig.22). Trunk with one abdominal segment distinctly longer than the others (fig.18).

Entomobrya nicoleti
Antenna with 4 segments. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body with many long dorsal setae. Dorsal pigmentation of the second and third abdominal segment in indistinct transversal patches (fig.18), (fig.21). Head not blackish. Thoracic dorsal pigmentation absent. Trunk with one abdominal segment distinctly longer than the others (fig.18).

Entomobrya nivalis
Antenna with 4 segments. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body with many long dorsal setae. Dorsal abdominal pigmentation in the shape of a capital U (fig.24). Head not blackish. Thoracic dorsal pigmentation present. Thoracic dorsal pigmentation in transversal bands. Trunk with one abdominal segment distinctly longer than the others (fig.18).

Entomobrya nivalis forma dorsalis
Antenna with 4 segments. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body with many long dorsal setae. Dorsal pigmentation of the second and third abdominal segment in distinct transversal bands (fig.20). Head not blackish. Thoracic dorsal pigmentation absent. Trunk with one abdominal segment distinctly longer than the others (fig.18).

Heteromurus major
Antenna with 5 segments (fig.4): basal antennomere subdivided. Apical antennomere about equal to subapical antennomere (fig.3). Body iridescent, covered with scales (fig.2). Body form elongate (fig.1a).

Isotoma anglicana adult
Body not iridescent, not covered with scales. Body with long dorsal setae. Body background colour uniform. Body background colour not greenish. Body background colour dark violet with distinct pale dot pattern lateral on abdomen (fig.17). Body form elongate (fig.1a). Body with few long dorsal setae. Head not blackish.

Isotoma anglicana juvenile
Body not iridescent, not covered with scales. Body with long dorsal setae. Body background colour uniform. Body background colour not greenish. Body background colour brownish with pale random dot pattern (fig.16). Body form elongate (fig.1a). Body with few long dorsal setae. Head not blackish.

Isotoma viridis
Body not iridescent, not covered with scales. Body with long dorsal setae. Body background colour uniform. Body background colour greenish (fig.15). Body form elongate (fig.1a). Body with few long dorsal setae. Head not blackish.

Isotoma viridis var annulata
Body not iridescent, not covered with scales. Body with long dorsal setae. Body background colour not uniform. Body form elongate (fig.1a). Body pigmentation in transversal pattern (fig.12). Body with few long dorsal setae. Head not blackish.

Isotoma viridis var violacea
Abdomen without whitish transversal band (fig.11). Body not iridescent, not covered with scales. Body form elongate (fig.1a). Head blackish.

Isotomurus maculatus
Body not iridescent, not covered with scales. Body with long dorsal setae. Body background colour not uniform. Body form elongate (fig.1a). Body pigmentation in longitudinal pattern. Body with few long dorsal setae. Head not blackish. Lateral thoracic pigmentation distinctly patchy. Middorsal segmental pigmentation in the shape of a crown (fig.13). Tibiotarsi distinctly differently coloured than femora.

Isotomurus palustris
Body not iridescent, not covered with scales. Body with long dorsal setae. Body background colour not uniform. Body form elongate (fig.1a). Body pigmentation in longitudinal pattern. Body with few long dorsal setae. Head not blackish. Lateral thoracic pigmentation indistinct. Middorsal segmental pigmentation in the shape of a solid line (fig.14). Tibiotarsi and femora equally coloured.

Orchesella cincta adult
Abdomen with distinct whitish transversal band (fig.9), (fig.10). Body not iridescent, not covered with scales. Body form elongate (fig.1a). Head blackish.

Orchesella cincta juvenile
Antenna with 6 segments (fig.19): basal two antennomeres subdivided. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body pigmentation in transversal bands (fig.27). Body pigmentation pattern in distinct bands. Body with many long dorsal setae. Head not blackish. Trunk with subequal abdominal segments.

Orchesella flavescens
Antenna with 6 segments (fig.19): basal two antennomeres subdivided. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body pigmentation in longitudinal bands (fig.26). Body pigmentation pattern in distinct bands. Body with many long dorsal setae. Head not blackish. Trunk with subequal abdominal segments.

Orchesella villosa
Antenna with 6 segments (fig.19): basal two antennomeres subdivided. Body not iridescent, not covered with scales. Body with long dorsal setae. Body form elongate (fig.1a). Body pigmentation pattern in complex pattern of patches (fig.25). Body with many long dorsal setae. Head not blackish. Trunk with subequal abdominal segments.

Pogonognathellus flavescens
Antenna with 4 segments. Apical antennomere much shorter then subapical antennomere. Body iridescent, covered with scales (fig.2). Body form elongate (fig.1a). Third antennal segment tapering (fig.6).

Tomocerus minor
Antenna with 4 segments. Apical antennomere much shorter then subapical antennomere. Body iridescent, covered with scales (fig.2). Body uniform bluish-grey (fig.8). Body form elongate (fig.1a). Third antennal segment subcylindric (fig.5).

Tomocerus vulgaris
Antenna with 4 segments. Apical antennomere much shorter then subapical antennomere. Body iridescent, covered with scales (fig.2). Body dark purplish with transversal goldish bands at intersegmental margins (fig.7). Body form elongate (fig.1a). Third antennal segment subcylindric (fig.5).

References