http://www.collembola.org/key/holaella.htm - Last updated on 2017.10.31 by Frans Janssens
Checklist of the Collembola: Key to the species of Holacanthella

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.

Mark Stevens, Allan Wilson Centre, Massey University, PB 11-222, Palmerston North, New Zealand
David Winter, Allan Wilson Centre, Massey University, PB 11-222, Palmerston North, New Zealand
Rod Morris, Rod Morris Productions, Dunedin 9021, New Zealand
Jay McCartney, Ecology Institute of Natural Resources, Massey University, PB 11-222, Palmerston North, New Zealand
Penelope Greenslade, Department of Botany and Zoology, Australian National University, Australian Capital Territory, 0200, Australia
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). Body covered in apically pointed digitations, including the
        first 2 antennal segments................................... 2
      Body covered in apically rounded digitations absent on antennal
        segments.................................................... 3
 
2(1). Body blue with most short digitations blue, longer digitations
        yellow; body covered in digitations of two distinct lengths;
        boundaries between tergites not concealed by an irregular
        arrangement of digitations; digitations with dark body colour
        pigment on the tip more than 20%; maximum or mean length of
        adults 17 mm....................................... duospinosa
      Body dark blue with yellow or white, rarely red or orange,
        tipped digitations; body covered in digitations of similar
        length; boundaries between tergites often concealed by an
        irregular arrangement of digitations; digitations with dark
        body colour pigment on the tip less than 10%; maximum or mean
        length of adults 10 mm................................ spinosa
 
3(1). Body blue, with red, orange or yellow, rarely white, tipped
        digitations; lateral digitations long some equal to or greater
        than the length of antennal segments i and ii, generally more
        than twice that of the dorsal digitations; maximum or mean
        length of adults 13 mm; postantennal organ with 20-25
        tubercules....................................... paucispinosa
      Body blue/grey, with yellow, rarely red/orange, tipped
        digitations, sometimes dorsal digitations same colour as body;
        lateral and dorsal digitations short and of similar length all
        less than the length of antennal segment i, dorsal digitations
        can be partially undeveloped; maximum or mean length of adults
        6 mm; postantennal organ with 25-35 tubercules.............. 4
 
4(3). Internal crest of claw apparently without tooth; body blue or
        grey with dorsal digitations tipped with same colour as body,
        but lateral digitations tipped with yellow, rarely red or
        orange; maximum or mean length of adults 5 mm; postantennal
        organ with 25-30 tubercules..................... laterospinosa
      Internal crest of claw with tooth; body blue or grey with
        yellow, rarely red or orange, tipped digitations; maximum or
        mean length of adults 6 mm; postantennal organ with 30-35
        tubercules....................................... brevispinosa

Endnotes

1 Salmon (1941, 1942) and Massoud (1967) included the claw, the amount of granulation and the presence or absence of a tooth in their keys. It was found these characters are not consistent between individuals (even when considering leg III only) unless specified above.


Differential diagnoses

brevispinosa
Body blue/grey, with yellow, rarely red/orange, tipped digitations, sometimes dorsal digitations same colour as body. Body blue or grey with yellow, rarely red or orange, tipped digitations. Body covered in apically rounded digitations absent on antennal segments. Internal crest of claw with tooth. Lateral and dorsal digitations short and of similar length all less than the length of antennal segment i, dorsal digitations can be partially undeveloped. Maximum or mean length of adults 6 mm. Maximum or mean length of adults 6 mm. Postantennal organ with 25–35 tubercules. Postantennal organ with 30–35 tubercules.

duospinosa
Body blue with most short digitations blue, longer digitations yellow. Body covered in apically pointed digitations, including the first 2 antennal segments. Body covered in digitations of two distinct lengths. Boundaries between tergites not concealed by an irregular arrangement of digitations. Digitations with dark body colour pigment on the tip more than 20%. Maximum or mean length of adults 17 mm.

laterospinosa
Body blue/grey, with yellow, rarely red/orange, tipped digitations, sometimes dorsal digitations same colour as body. Body blue or grey with dorsal digitations tipped with same colour as body, but lateral digitations tipped with yellow, rarely red or orange. Body covered in apically rounded digitations absent on antennal segments. Internal crest of claw apparently without tooth. Lateral and dorsal digitations short and of similar length all less than the length of antennal segment i, dorsal digitations can be partially undeveloped. Maximum or mean length of adults 6 mm. Maximum or mean length of adults 5 mm. Postantennal organ with 25–35 tubercules. Postantennal organ with 25–30 tubercules.

paucispinosa
Body blue, with red, orange or yellow, rarely white, tipped digitations. Body covered in apically rounded digitations absent on antennal segments. Lateral digitations long some equal to or greater than the length of antennal segments i and ii, generally more than twice that of the dorsal digitations. Maximum or mean length of adults 13 mm. Postantennal organ with 20–25 tubercules.

spinosa
Body dark blue with yellow or white, rarely red or orange, tipped digitations. Body covered in apically pointed digitations, including the first 2 antennal segments. Body covered in digitations of similar length. Boundaries between tergites often concealed by an irregular arrangement of digitations. Digitations with dark body colour pigment on the tip less than 10%. Maximum or mean length of adults 10 mm.


References