http://www.collembola.org/key/arrhidae.htm - Last updated on 2017.06.30 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). Secondary seta FSa on all tibiotarsi present (fig.1b); seta p of
        first abdominal segment is located below the level of
        trichobothrium B............................. Pygmarrhopalites
      Secondary seta FSa on protibiotarsus and mesotibiotarsus absent
        (fig.1a); seta p of first abdominal segment is located at
        least on or above the level of trichobothrium B............. 2
 

Fig.1.
 
2(1). Circumanal row on sixth abdominal segment nearly complete: setae
        mps3 and mpi1 optional; fourth antennal segment with up to 15
        whorls of setae; trichobothrial pattern caecus-type: ABC angle
        is suborthogonal (fig.2a)........................ Arrhopalites
      Circumanal row on sixth abdominal segment strongly reduced:
        mps1, mps3, mpi1 and mpi2 are absent; fourth antennal segment
        with 20 whorls of setae; trichobothrial pattern pygmaeus-type:
        ABC angle is close to flat (fig.2b)............. Troglopalites

Fig.2.
 


Differential diagnoses

Arrhopalites
Circumanal row on sixth abdominal segment nearly complete: setae mps3 and mpi1 optional. Fourth antennal segment with up to 15 whorls of setae. Secondary seta FSa on protibiotarsus and mesotibiotarsus absent (fig.1a). Seta p of first abdominal segment is located at least on or above the level of trichobothrium B. Trichobothrial pattern caecus-type: ABC angle is suborthogonal (fig.2a).

Pygmarrhopalites
Secondary seta FSa on all tibiotarsi present (fig.1b). Seta p of first abdominal segment is located below the level of trichobothrium B.

Troglopalites
Circumanal row on sixth abdominal segment strongly reduced: mps1, mps3, mpi1 and mpi2 are absent. Fourth antennal segment with 20 whorls of setae. Secondary seta FSa on protibiotarsus and mesotibiotarsus absent (fig.1a). Seta p of first abdominal segment is located at least on or above the level of trichobothrium B. Trichobothrial pattern pygmaeus-type: ABC angle is close to flat (fig.2b).


References