http://www.collembola.org/key/heteella.htm - Last updated on 2014.02.28 by Frans Janssens
Checklist of the Collembola: Key to the species of Heteromurtrella

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.

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 absent............................................. caeca
        Eyes present................................................ 2
 
2(1).   Dental spines absent........................................ 3
        Dental spines present...................................... 18
 
3(2).   Eyes 2 + 2 or 1 + 1......................................... 4
        Eyes 6 + 6............................................ abrupta
 
4(3).   Pigment absent, restricted to eye patch, restricted to
          anterior portion of head and to antennae or if diffused
          throughout head and body it is very light and visible only
          under magnification....................................... 5
        Pigment present on head and body........................... 15
 
5(4).   First abdominal segment with 1 or 2 macrochaetae per side... 6
        First abdominal segment with 3 or 4 macrochaetae per side... 8
 
6(5).   Mucro with basal spine; number of p macrochaetae 1; pigment
          fairly concentrated and restricted to anterior portion of
          head and to antennae; unguiculus with inner tooth......... 7
        Mucro without basal spine; number of p macrochaetae 3; pigment
          very diffuse on antennae, head, body and coxae, only visible
          under high magnification; unguiculus without tooth on inner
          margin............................................ stannardi
 
7(6).   Outer pair of macrochaetae of third thoracic segment close
          together; first abdominal segment with 1 macrochaeta per
          side............................................... mirifica
        Outer pair of macrochaetae of third thoracic segment far
          apart; first abdominal segment with 2 macrochaetae per side.
           ................................................... similis
 
8(5).   First abdominal segment with 3 macrochaetae per side........ 9
        First abdominal segment with 4 macrochaetae per side....... 14
 
9(8).   Second thoracic segment with 2 or 3 inner posterior setae.. 10
        Second thoracic segment with 4 inner posterior setae....... 13
 
10(9).  Number of p macrochaetae 2; second thoracic segment with 2
          inner posterior setae; unguiculus with inner toothlike
          projection........................................... barrai
        Number of p macrochaetae 3; second thoracic segment with 3
          inner posterior setae; unguiculus without inner toothlike
          projection............................................... 11
 
11(10). Mucro with basal spine; eyes surrounded by pigment......... 12
        Mucro without basal spine; eyes not surrounded by pigment.....
           .................................................. subdubia
 
12(11). Differentiated seta of outer labial papilla not reaching apex
          of its papilla; tibiotarsi with conspicuously ciliated
          setae........................................ puertoricensis
        Differentiated seta of outer labial papilla reaching apex of
          its papilla; tibiotarsi with inner row of smooth, very
          finely striated, setae................................ dubia
 
13(9).  Third thoracic segment with 6 macrochaetae per side.. schoetti
        Third thoracic segment with 7 macrochaetae per side.... nitens
 
14(8).  Head macrochaeta m3 absent; head macrochaeta p4 present.......
           .................................................. pruinosa
        Head macrochaeta m3 present; head macrochaeta p4 absent.......
           .................................................. echinata 2
 
15(4).  Head and body pigmented deeply............................. 16
        Head and body pigmented with dispersed light orange........ 17
 
16(15). Unguis long, basally slender, tridentate............. diommata
        Unguis relatively short, basally wide bidentate........ livida
 
17(15). Fourth abdominal segment with 1 middorsal macrochaeta; second
          thoracic segment with 7 p-setae................ greensladeae
        Fourth abdominal segment with 2 middorsal macrochaetae; second
          thoracic segment with 6 p-setae..................... affinis
 
18(2).  Mucro with conspicuous basal spine................... echinata
        Mucro without basal spine or exceptionally with a very
          slender, needlelike, inconspicuous spine......... tihuiensis

Endnotes

1 The system for naming head macrochaetae is described in Mari Mutt, 1979.

2 Some specimens of H. echinata lack dental spines. This is the first record of such intraspecific variation (Mari Mutt, 1983).

Differential diagnoses

abrupta
Dental spines absent. Eyes present. Eyes 6 + 6.

affinis
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. Fourth abdominal segment with 2 middorsal macrochaetae. Head and body pigmented with dispersed light orange. Pigment present on head and body. Second thoracic segment with 6 p-setae.

barrai
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 3 macrochaetae per side. Number of p macrochaetae 2. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Second thoracic segment with 2 or 3 inner posterior setae. Second thoracic segment with 2 inner posterior setae. Unguiculus with inner toothlike projection.

caeca
Eyes absent.

diommata
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. Head and body pigmented deeply. Pigment present on head and body. Unguis long, basally slender, tridentate.

dubia
Dental spines absent. Differentiated seta of outer labial papilla reaching apex of its papilla. Eyes present. Eyes surrounded by pigment. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 3 macrochaetae per side. Mucro with basal spine. Number of p macrochaetae 3. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Second thoracic segment with 2 or 3 inner posterior setae. Second thoracic segment with 3 inner posterior setae. Tibiotarsi with inner row of smooth, very finely striated, setae. Unguiculus without inner toothlike projection.

echinata
Dental spines present. Eyes present. Mucro with conspicuous basal spine.

echinata 2
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 4 macrochaetae per side. Head macrochaeta m3 present. Head macrochaeta p4 absent. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification.

greensladeae
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. Fourth abdominal segment with 1 middorsal macrochaeta. Head and body pigmented with dispersed light orange. Pigment present on head and body. Second thoracic segment with 7 p-setae.

livida
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. Head and body pigmented deeply. Pigment present on head and body. Unguis relatively short, basally wide bidentate.

mirifica
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 1 or 2 macrochaetae per side. First abdominal segment with 1 macrochaeta per side. Mucro with basal spine. Number of p macrochaetae 1. Outer pair of macrochaetae of third thoracic segment close together. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Pigment fairly concentrated and restricted to anterior portion of head and to antennae. Unguiculus with inner tooth.

nitens
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 3 macrochaetae per side. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Second thoracic segment with 4 inner posterior setae. Third thoracic segment with 7 macrochaetae per side.

pruinosa
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 4 macrochaetae per side. Head macrochaeta m3 absent. Head macrochaeta p4 present. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification.

puertoricensis
Dental spines absent. Differentiated seta of outer labial papilla not reaching apex of its papilla. Eyes present. Eyes surrounded by pigment. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 3 macrochaetae per side. Mucro with basal spine. Number of p macrochaetae 3. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Second thoracic segment with 2 or 3 inner posterior setae. Second thoracic segment with 3 inner posterior setae. Tibiotarsi with conspicuously ciliated setae. Unguiculus without inner toothlike projection.

schoetti
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 3 macrochaetae per side. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Second thoracic segment with 4 inner posterior setae. Third thoracic segment with 6 macrochaetae per side.

similis
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 1 or 2 macrochaetae per side. First abdominal segment with 2 macrochaetae per side. Mucro with basal spine. Number of p macrochaetae 1. Outer pair of macrochaetae of third thoracic segment far apart. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Pigment fairly concentrated and restricted to anterior portion of head and to antennae. Unguiculus with inner tooth.

stannardi
Dental spines absent. Eyes present. Eyes 2 + 2 or 1 + 1. First abdominal segment with 1 or 2 macrochaetae per side. Mucro without basal spine. Number of p macrochaetae 3. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Pigment very diffuse on antennae, head, body and coxae, only visible under high magnification. Unguiculus without tooth on inner margin.

subdubia
Dental spines absent. Eyes present. Eyes not surrounded by pigment. Eyes 2 + 2 or 1 + 1. First abdominal segment with 3 or 4 macrochaetae per side. First abdominal segment with 3 macrochaetae per side. Mucro without basal spine. Number of p macrochaetae 3. Pigment absent, restricted to eye patch, restricted to anterior portion of head and to antennae or if diffused throughout head and body it is very light and visible only under magnification. Second thoracic segment with 2 or 3 inner posterior setae. Second thoracic segment with 3 inner posterior setae. Unguiculus without inner toothlike projection.

tihuiensis
Dental spines present. Eyes present. Mucro without basal spine or exceptionally with a very slender, needlelike, inconspicuous spine.

References