http://www.collembola.org/key/arrhidae.htm - Last updated on 2009.09.30 by Frans Janssens
Checklist of the Collembola: Key to the genera of Arrhopalitidae

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.

Robert S. Vargovitsh, Schmalhausen Institute of Zoology NAS of Ukraine, Kyiv, 01601, Ukraine
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). Anterior side of dens with 4 transverse rows of setae: 3, 2, 1,
        1 (fig.1b); cuticular spines on sixth abdominal segment always
        absent; tibiotarsi of foreleg and mid leg with secondary seta
        FS (fig.2b); trichobothrial pattern pygmaeus-type: ABC form
        very obtuse angle and AB less than or equal to BC (fig.3b)....
         ............................................ Pygmarrhopalites
      Anterior side of dens with 5, rarely 4, transverse rows of
        setae: 3, 2, 1 or 2, 1, 1 or 0 (fig.1a); cuticular spines on
        sixth abdominal segment present or absent; tibiotarsi of
        foreleg and mid leg without secondary seta FS (fig.2a);
        trichobothrial pattern caecus-type: ABC form about right angle
        and AB longer than or equal to BC (fig.3a)....... Arrhopalites

Fig.1.
  

Fig.2.
  

Fig.3.
  

Differential diagnoses

Arrhopalites
Anterior side of dens with 5, rarely 4, transverse rows of setae: 3, 2, 1 or 2, 1, 1 or 0 (fig.1a). Cuticular spines on sixth abdominal segment present or absent. Tibiotarsi of foreleg and mid leg without secondary seta FS (fig.2a). Trichobothrial pattern caecus-type: ABC form about right angle and AB longer than or equal to BC (fig.3a).

Pygmarrhopalites
Anterior side of dens with 4 transverse rows of setae: 3, 2, 1, 1 (fig.1b). Cuticular spines on sixth abdominal segment always absent. Tibiotarsi of foreleg and mid leg with secondary seta FS (fig.2b). Trichobothrial pattern pygmaeus-type: ABC form very obtuse angle and AB less than or equal to BC (fig.3b).

References