http://www.collembola.org/key/monobell.htm - Last updated on 2009.09.30 by Frans Janssens
Checklist of the Collembola: Key to the species of Monobella

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.

Anne Bedos, Laboratoire d'Ecologie Terrestre, UMR 5552 du CNRS, UPS, Toulouse Cedex 4, 31062, France
Louis Deharveng, Laboratoire d'Ecologie Terrestre, UMR 5552 du CNRS, UPS, Toulouse Cedex 4, 31062, France
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).   Labrum distally ogival (fig.1).............................. 2
        Labrum non-ogival........................................... 4

Fig.1.
   
2(1).   Third abdominal segment with the dorso-internal tubercles
          fused............................................ cassagnaui
        Third abdominal segment with the dorso-internal tubercles
          separate.................................................. 3
 

3(2).   Third abdominal segment to second thoracic segment with the
          dorso-internal and dorso-external tubercles fused.. rostrata
        Third abdominal segment to second thoracic segment with the
          dorso-internal and dorso-external tubercles separate
          (fig.2)........................................... rousseti

Fig.2.
   
4(1).   First antennal segment with 7 chaetae....................... 5
        First antennal segment with 8-9 chaetae.................... 12
 

5(4).   Second thoracic segment with the dorso-internal and
          dorso-external tubercles fused............................ 6
        Second thoracic segment with the dorso-internal and
          dorso-external tubercles separate......................... 7
 

6(5).   Head with chaetae c always short macrochaetae, at the level of
          the chaetae b (fig.3a); short macrochaetae broad...... minor
        Head with chaetae c microchaetae or short macrochaetae, ahead
          the chaetae b (fig.3b); short macrochaetae thin..... grassei

Fig.3.
   
7(5).   Fourth abdominal segment with the dorso-external tubercles
          fused to the dorso-internal tubercles..................... 8
        Fourth abdominal segment with the dorso-external tubercles not
          fused to the dorso-internal tubercles..................... 9
 

8(7).   Head with chaetae di2, de2, dl6 absent or minute microchaetae.
           ..................................................... calva
        Head with chaetae di2, de2, dl6 short macrochaetae............
           .............................................. prodistincta
 

9(7).   Fifth abdominal segment with 6 chaetae, 5 + s, on the tubercle
          de + dl + l; third abdominal segment with 4 chaetae ve......
           ................................................. pyrenaica
        Fifth abdominal segment with 7-8 chaetae, 6-7 + s on the
          tubercle de + dl + l, rarely 5 + s on one side; third
          abdominal segment with 5-7 chaetae ve.................... 10
 

10(9).  Fourth abdominal segment with 6-7 chaetae on the tubercle l...
           ........................................................ 11
        Fourth abdominal segment with 8 chaetae on the tubercle l.....
           ..................................................... gersi
 

11(10). Body size less than 1.5 mm; second abdominal segment with 5
          chaetae ve; short macrochaetae enlarged (fig.4b)... edaphica
        Body size more than 1.9 mm; second abdominal segment with 6-7
          chaetae ve; short macrochaetae thin (fig.4a)............ jau

Fig.4.
   
12(4).  Fourth abdominal segment with the dorso-external tubercles
          fused to the dorso-internal tubercles.................... 13
        Fourth abdominal segment with the dorso-external tubercles not
          fused to the dorso-internal tubercles................. dubia
 

13(12). Second thoracic segment with the dorso-internal and
          dorso-external tubercles fused.................. banyulensis
        Second thoracic segment with the dorso-internal and
          dorso-external tubercles separate................. distincta

Differential diagnoses

banyulensis
First antennal segment with 8–9 chaetae. Fourth abdominal segment with the dorso-external tubercles fused to the dorso-internal tubercles. Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles fused.

calva
First antennal segment with 7 chaetae. Fourth abdominal segment with the dorso-external tubercles fused to the dorso-internal tubercles. Head with chaetae di2, de2, dl6 absent or minute microchaetae. Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles separate.

cassagnaui
Labrum distally ogival (fig.1). Third abdominal segment with the dorso-internal tubercles fused.

distincta
First antennal segment with 8–9 chaetae. Fourth abdominal segment with the dorso-external tubercles fused to the dorso-internal tubercles. Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles separate.

dubia
First antennal segment with 8–9 chaetae. Fourth abdominal segment with the dorso-external tubercles not fused to the dorso-internal tubercles. Labrum non-ogival.

edaphica
Body size less than 1.5 mm. Fifth abdominal segment with 7–8 chaetae, 6–7 + s on the tubercle de + dl + l, rarely 5 + s on one side. First antennal segment with 7 chaetae. Fourth abdominal segment with 6–7 chaetae on the tubercle l. Fourth abdominal segment with the dorso-external tubercles not fused to the dorso-internal tubercles. Labrum non-ogival. Second abdominal segment with 5 chaetae ve. Second thoracic segment with the dorso-internal and dorso-external tubercles separate. Short macrochaetae enlarged (fig.4b). Third abdominal segment with 5–7 chaetae ve.

gersi
Fifth abdominal segment with 7–8 chaetae, 6–7 + s on the tubercle de + dl + l, rarely 5 + s on one side. First antennal segment with 7 chaetae. Fourth abdominal segment with 8 chaetae on the tubercle l. Fourth abdominal segment with the dorso-external tubercles not fused to the dorso-internal tubercles. Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles separate. Third abdominal segment with 5–7 chaetae ve.

grassei
First antennal segment with 7 chaetae. Head with chaetae c microchaetae or short macrochaetae, ahead the chaetae b (fig.3b). Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles fused. Short macrochaetae thin.

jau
Body size more than 1.9 mm. Fifth abdominal segment with 7–8 chaetae, 6–7 + s on the tubercle de + dl + l, rarely 5 + s on one side. First antennal segment with 7 chaetae. Fourth abdominal segment with 6–7 chaetae on the tubercle l. Fourth abdominal segment with the dorso-external tubercles not fused to the dorso-internal tubercles. Labrum non-ogival. Second abdominal segment with 6–7 chaetae ve. Second thoracic segment with the dorso-internal and dorso-external tubercles separate. Short macrochaetae thin (fig.4a). Third abdominal segment with 5–7 chaetae ve.

minor
First antennal segment with 7 chaetae. Head with chaetae c always short macrochaetae, at the level of the chaetae b (fig.3a). Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles fused. Short macrochaetae broad.

prodistincta
First antennal segment with 7 chaetae. Fourth abdominal segment with the dorso-external tubercles fused to the dorso-internal tubercles. Head with chaetae di2, de2, dl6 short macrochaetae. Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles separate.

pyrenaica
Fifth abdominal segment with 6 chaetae, 5 + s, on the tubercle de + dl + l. First antennal segment with 7 chaetae. Fourth abdominal segment with the dorso-external tubercles not fused to the dorso-internal tubercles. Labrum non-ogival. Second thoracic segment with the dorso-internal and dorso-external tubercles separate. Third abdominal segment with 4 chaetae ve.

rostrata
Labrum distally ogival (fig.1). Third abdominal segment to second thoracic segment with the dorso-internal and dorso-external tubercles fused. Third abdominal segment with the dorso-internal tubercles separate.

rousseti
Labrum distally ogival (fig.1). Third abdominal segment to second thoracic segment with the dorso-internal and dorso-external tubercles separate (fig.2). Third abdominal segment with the dorso-internal tubercles separate.

References