http://www.collembola.org/key/isotogas.htm - Last updated on 2009.02.09 by Frans Janssens
Checklist of the Collembola: Key to the species of Isotogastrura

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.

Jean-Marc Thibaud, Muséum National d'Histoire Naturelle, Département Systématique et Evolution, Laboratoire d'Entomologie, F-75231 Paris, 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). Fifth abdominal tergite with a posterior median tegumentary
        tubercle.................................................... 2
      Fifth abdominal tergite without a posterior median tegumentary
        tubercle (fig.1)............................................ 4

Fig.1.
   
2(1). First abdominal sternite with 2 median setae; third abdominal
        tergite with a pair of posterior median tegumentary tubercles.
         ................................................... arenicola
      First abdominal sternite with only 1 median setae; third
        abdominal tergite without a pair of posterior median
        tegumentary tubercles (fig.2)............................... 3

Fig.2.
   
3(2). Prelabral microsetae absent......................... veracruzana
      Prelabral microsetae present 1 + 1.................... ahuizotli
 

4(1). Third abdominal tergite with a pair of posterior median
        tegumentary tubercles............................... litoralis
      Third abdominal tergite without a pair of posterior median
        tegumentary tubercles (fig.2)............................... 5
 

5(4). Each tergite, from second thoracic tergite to abdominal tergite
        ii, with a pair of posterior median tegumentary tubercles.....
         .................................................... coronata
      Each tergite, from second thoracic tergite to abdominal tergite
        vi, without a pair of posterior median tegumentary tubercles..
         ........................................................... 6
 

6(5). Prelabral microsetae absent; sensilla of sense organ of third
        antennal segment bifid; dens with 4 setae........ atuberculata
      Prelabral microsetae present 1 + 1; sensilla of sense organ of
        third antennal segment simple (fig.3); dens with 3 setae
        (fig.4)...................................... madagascariensis

Fig.3.
  

Fig.4.
  

Differential diagnoses

ahuizotli
Fifth abdominal tergite with a posterior median tegumentary tubercle. First abdominal sternite with only 1 median setae. Prelabral microsetae present 1 + 1. Third abdominal tergite without a pair of posterior median tegumentary tubercles (fig.2).

arenicola
Fifth abdominal tergite with a posterior median tegumentary tubercle. First abdominal sternite with 2 median setae. Third abdominal tergite with a pair of posterior median tegumentary tubercles.

atuberculata
Dens with 4 setae. Each tergite, from second thoracic tergite to abdominal tergite vi, without a pair of posterior median tegumentary tubercles. Fifth abdominal tergite without a posterior median tegumentary tubercle (fig.1). Prelabral microsetae absent. Sensilla of sense organ of third antennal segment bifid. Third abdominal tergite without a pair of posterior median tegumentary tubercles (fig.2).

coronata
Each tergite, from second thoracic tergite to abdominal tergite ii, with a pair of posterior median tegumentary tubercles. Fifth abdominal tergite without a posterior median tegumentary tubercle (fig.1). Third abdominal tergite without a pair of posterior median tegumentary tubercles (fig.2).

litoralis
Fifth abdominal tergite without a posterior median tegumentary tubercle (fig.1). Third abdominal tergite with a pair of posterior median tegumentary tubercles.

madagascariensis
Dens with 3 setae (fig.4). Each tergite, from second thoracic tergite to abdominal tergite vi, without a pair of posterior median tegumentary tubercles. Fifth abdominal tergite without a posterior median tegumentary tubercle (fig.1). Prelabral microsetae present 1 + 1. Sensilla of sense organ of third antennal segment simple (fig.3). Third abdominal tergite without a pair of posterior median tegumentary tubercles (fig.2).

veracruzana
Fifth abdominal tergite with a posterior median tegumentary tubercle. First abdominal sternite with only 1 median setae. Prelabral microsetae absent. Third abdominal tergite without a pair of posterior median tegumentary tubercles (fig.2).

References