http://www.collembola.org/key/typhrura.htm - Last updated on 2017.10.31 by Frans Janssens
Checklist of the Collembola: Key to the species of Typhlogastrura, partim North America

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.

Kenneth A. Christiansen, Department of Biology, Grinnell College, PO Box V3, Grinnell, IA 50112-0806, USA
Hanghang Wang, Department of Biology, Grinnell College, PO Box V3, Grinnell, IA 50112-0806, USA
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). Eyes 0 + 0 or 1 + 1........................................... 2
      Eyes at least 3 + 3........................................... 3
 
2(1). Fourth antennal segment with seven blunt, thick setae...........
         .................................................. elsarzolae
      Fourth antennal segment with ten blunt, thick setae. veracruzana
 
3(1). Fifth abdominal segment with a clear median swelling (fig.3)....
         ....................................................... unica
      Fifth abdominal segment without a clear median swelling....... 4
 
4(3). Fifth abdominal segment with three-four setae between the p1
        setae level (fig.4a).............................. alabamensis
      Fifth abdominal segment with two setae between the p1 setae
        level (fig.4b).............................................. 5
 
5(4). Apical antennal bulb large and double (fig.5a)....... steinmanni
      Apical antennal bulb small and single, sometimes apically
        indented (fig.5b)........................................... 6
 
6(5). Fifth abdominal segment with seta p2 and/or p4 absent......... 7
      Fifth abdominal segment with setae p1-p5 all present (fig.2).. 9
 
7(6). B/a ratio on second thoracic segment greater than 3.0 (fig.6b)..
         ........................................................... 8
      B/a ratio on second thoracic segment less than 1.8 (fig.6a).....
         ................................................. asymmetrica
 
8(7). Fifth abdominal segment with both setae p2 and p4 (fig.2)
        absent.......................................... christianseni
      Fifth abdominal segment with seta p4 present.......... valentini
 
9(6). Eyes 4 + 4.......................................... fousheensis
      Eyes 5 + 5 or 6 + 6..................................... helleri

Differential diagnoses

alabamensis
Eyes at least 3 + 3. Fifth abdominal segment without a clear median swelling. Fifth abdominal segment with three-four setae between the p1 setae level (fig.a).

asymmetrica
Apical antennal bulb small and single, sometimes apically indented (fig.b). B/a ratio on second thoracic segment less than 1.8 (fig.a). Eyes at least 3 + 3. Fifth abdominal segment without a clear median swelling. Fifth abdominal segment with two setae between the p1 setae level (fig.b). Fifth abdominal segment with seta p2 and/or p4 absent.

christianseni
Apical antennal bulb small and single, sometimes apically indented (fig.b). B/a ratio on second thoracic segment greater than fig..0 (fig.b). Eyes at least 3 + 3. Fifth abdominal segment without a clear median swelling. Fifth abdominal segment with two setae between the p1 setae level (fig.b). Fifth abdominal segment with seta p2 and/or p4 absent. Fifth abdominal segment with both setae p2 and p4 (fig.) absent.

elsarzolae
Eyes 0 + 0 or 1 + 1. Fourth antennal segment with seven blunt, thick setae.

fousheensis
Apical antennal bulb small and single, sometimes apically indented (fig.b). Eyes at least 3 + 3. Eyes 4 + 4. Fifth abdominal segment without a clear median swelling. Fifth abdominal segment with two setae between the p1 setae level (fig.b). Fifth abdominal segment with setae p1-p5 all present (fig.).

helleri
Apical antennal bulb small and single, sometimes apically indented (fig.b). Eyes at least 3 + 3. Eyes 5 + 5 or 6 + 6. Fifth abdominal segment without a clear median swelling. Fifth abdominal segment with two setae between the p1 setae level (fig.b). Fifth abdominal segment with setae p1-p5 all present (fig.).

steinmanni
Apical antennal bulb large and double (fig.a). Eyes at least 3 + 3. Fifth abdominal segment without a clear median swelling. Fifth abdominal segment with two setae between the p1 setae level (fig.b).

unica
Eyes at least 3 + 3. Fifth abdominal segment with a clear median swelling (fig.).

valentini
Apical antennal bulb small and single, sometimes apically indented (fig.b). B/a ratio on second thoracic segment greater than fig..0 (fig.b). Eyes at least 3 + 3. Fifth abdominal segment without a clear median swelling. Fifth abdominal segment with two setae between the p1 setae level (fig.b). Fifth abdominal segment with seta p2 and/or p4 absent. Fifth abdominal segment with seta p4 present.

veracruzana
Eyes 0 + 0 or 1 + 1. Fourth antennal segment with ten blunt, thick setae.


References