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

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.

Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium

Preamble

An experimental inter-active version of this key is also available for evaluation.

Acknowledgements

I thank Dr Arne Fjellberg for his advice on how to incorporate Agrenia lamellosa into the key and also for providing constructive comments.

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). Mucronal lateral seta absent.................................. 2
      Mucronal lateral seta present................................. 5
 
2(1). Antennae 2-3 times head diagonal; ventral tube with 10 or more
        frontal setae on each side.................................. 3
      Antennae less than two times head diagonal; ventral tube with at
        most 1-2 frontal setae...................................... 4
 
3(2). Abdomen with open, uniform setal cover; antennae 2.4-2.7 as long
        as head diagonal; body colour grayish-green or dirty
        reddish-gray; body pigmentation rather uniform; claw index
        2.8-3.1: claw shape unusually long and slender (fig.1a).......
         ...................................................... agilis
      Abdomen with very dense, uniform setal cover; antennae 2.0-2.6
        as long as head diagonal; body colour pale yellowish-green;
        body pigmentation with darker sections; claw index 2.0-2.3:
        claw shape not long and slender (fig.1b).............. cyanura
 
4(2). A ventral tube with 0 frontal setae and usually with less than
        20 caudal setae; antennae 1.5-1.7 as long as head diagonal;
        body colour dark greenish-black; claw index 1.7-2.0: claws
        rather short and thick; frontoclypeal field with very sparse
        and open setal cover.............................. atroviridis
      A ventral tube with 0-2 frontal setae and normally with more
        than 20 caudal setae; antennae 1.5-1.8 as long as head
        diagonal; body colour brownish or olive green; claw index
        2.1-2.5[summer] or 1.2-1.3[winter]; frontoclypeal field with a
        dense cover of unmodified setae....................... riparia
 
5(1). Abdomen with differentiated short and long setae, anteriorly;
        antennae always more than 2 times head diagonal: 2.3-2.8; body
        colour grayish olive-green or grayish-blue; claw index
        2.0-2.4; frontoclypeal field with a distinct 'moustache'......
         ...................................................... pilosa
      Abdomen with undifferentiated short and long setae, anteriorly;
        antennae sometimes less than 2 times head diagonal; body
        colour not grayish olive-green or grayish-blue; claw index not
        2.0-2.4; frontoclypeal field with an open cover of
        undifferentiated setae...................................... 6
 
6(5). Body pigmentation rather uniform; mucronal ventral lamella
        broad............................................... lamellosa
      Body pigmentation uniform or with darker sections; mucronal
        ventral lamella narrow, keel-like........................... 7
 
7(6). Antennae 1.5-3.1 as long as head diagonal; body colour pale gray
        to olive or yellowish-brown; body pigmentation uniform; a
        ventral tube with 1-12 frontal setae; claw index [1.2]1.9-2.6.
         .................................................. polymorpha
      Antennae 1.6-2.2 as long as head diagonal; body colour olive
        green to dirty yellowish; body pigmentation with distinctly
        darker dorsal mid-section of thorax and abdomen; a ventral
        tube with 2-12 frontal setae; claw index 1.8-2.7..............
         ............................................... bidenticulata

References