http://www.collembola.org/key/american.htm - Last updated on 2020.05.31 by Frans Janssens
Checklist of the Collembola: Key to the species of Americanura

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.

José G. Palacios-Vargas, Ecología y Sistemática de Microartrópodos, Departamento de Ecología y Recursos Naturales, Facultad de Ciensas, UNAM, 04510 México D.F.
Jorge Paniagua Nucamendi, Laboratorio de Ecología y Sistemática de Microartrópodos, Departamento de Ecología y Recursos Naturales, Facultad de Ciensas, UNAM, 04510 México D.F.
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).   Dorso-internal tubercles on second thoracic segment with 3
          setae..................................................... 2
        Dorso-internal tubercles on second thoracic segment with less
          than 3 setae............................................. 12
 

2(1).   Cephalic seta A absent...................................... 3
        Cephalic seta A present (fig.1)............................ 7

Fig.1.
   
3(2).   Thoracic dorso-lateral tubercle with 2 setae........ palaciosi
        Thoracic dorso-lateral tubercle with 3 setae................ 4
 

4(3).   Cephalic dorso-external tubercle with 2 setae....... medellini
        Cephalic dorso-external tubercle with 3 setae............... 5
 

5(4).   Ocular tubercle with less than 3 setae...................... 6
        Ocular tubercle with three setae (fig.2)........ sardinasensis

Fig.2.
   
6(5).   Ocular tubercle with one seta (fig.3a)............ macgregori
        Ocular tubercle with two setae (fig.3b)................ iztac

Fig.3.
   
7(2).   Cephalic dorso-external tubercle with 2 setae............... 8
        Cephalic dorso-external tubercle with 3 setae............... 9
 

8(7).   Ocular tubercle with three setae; unguis with one tooth.......
           ................................................. unguimitl
        Ocular tubercle with two setae; unguis without teeth..........
           ............................................... castillorum
 

9(7).   Dorso-external and dorsolateral tubercle on second abdominal
          segment with 2 setae; eyes 2 + 2 (fig.4)................. 10
        Dorso-external and dorsolateral tubercle on second abdominal
          segment with 3 setae; eyes absent...................... nova

Fig.4.
   
10(9).  Body setae barbulate (fig.5b) (fig.6) (fig.7); on fourth
          abdominal segment tubercle dorsolateral tubercle with setae.
           ........................................................ 11
        Body setae smooth (fig.5a); on fourth abdominal segment
          tubercle dorsolateral tubercle without setae.......... prima

Fig.5.
  

Fig.6.
  

Fig.7.
   
11(10). Dorsolateral tubercle and lateral tubercle on fourth abdominal
          segment fused...................................... imitator
        Dorsolateral tubercle and lateral tubercle on fourth abdominal
          segment not fused.................................. mexicana
 

12(1).  Dorso-internal tubercles on second thoracic segment with only
          one seta................................................. 13
        Dorso-internal tubercles on second thoracic segment with two
          setae.................................................... 20
 

13(12). Cephalic setae absent...................................... 14
        Cephalic setae present..................................... 17
 

14(13). Ocular tubercle with one seta.............................. 15
        Ocular tubercle with two setae............................. 16
 

15(14). Dorsolateral tubercle on second thoracic segment and third
          thoracic segment with one seta; lateral tubercle on first
          and second abdominal segment with 2 setae 100b lateral
          tubercle on first and second abdominal segment with 2 setae.
           .............................................. guatemalteca
        Dorsolateral tubercle on second thoracic segment and third
          thoracic segment with with 2 setae; lateral tubercle on
          first and second abdominal segment with 2 setae 100a lateral
          tubercle on first and second abdominal segment with 2 setae.
           ............................................... castagnorum
 

16(14). Dorsolateral tubercle on first and second abdominal segment
          with 1 seta; dorsolateral tubercle on second thoracic
          segment and iii with 1 seta.................... setafoliacea
        Dorsolateral tubercle on first and second abdominal segment
          with 2 setae; dorsolateral tubercle on second thoracic
          segment and third thoracic segment with 3 setae..... basseti
 

17(13). Ocular tubercle with three setae......................... bara
        Ocular tubercle with two setae............................. 18
 

18(17). Dorsolateral tubercle on second thoracic segment and third
          thoracic segment with 2 setae............................ 19
        Dorsolateral tubercle on second thoracic segment and third
          thoracic segment with 3 setae.................. interrogator
 

19(18). Lateral tubercle on second thoracic segment and third thoracic
          segment with 2 setae................................. banksi
        Lateral tubercle on second thoracic segment and third thoracic
          segment with 3 setae............................ sotanophila
 

20(12). Ocular tubercle with only one seta; tubercles on third
          abdominal segment and/or fourth abdominal segment some
          fused............................................. izabalana
        Ocular tubercle with two setae; tubercles on third abdominal
          segment and/or fourth abdominal segment not fused. janssensi

Differential diagnoses

banksi
Cephalic setae present. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Dorsolateral tubercle on second thoracic segment and third thoracic segment with 2 setae. Lateral tubercle on second thoracic segment and third thoracic segment with 2 setae. Ocular tubercle with two setae.

bara
Cephalic setae present. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Ocular tubercle with three setae.

basseti
Cephalic setae absent. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Dorsolateral tubercle on first and second abdominal segment with 2 setae. Dorsolateral tubercle on second thoracic segment and third thoracic segment with 3 setae. Ocular tubercle with two setae.

castagnorum
Cephalic setae absent. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Dorsolateral tubercle on second thoracic segment and third thoracic segment with with 2 setae. Lateral tubercle on first and second abdominal segment with 2 setae 100a lateral tubercle on first and second abdominal segment with 2 setae. Ocular tubercle with one seta.

castillorum
Cephalic dorso-external tubercle with 2 setae. Cephalic seta A present (fig.1). Dorso-internal tubercles on second thoracic segment with 3 setae. Ocular tubercle with two setae. Unguis without teeth.

guatemalteca
Cephalic setae absent. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Dorsolateral tubercle on second thoracic segment and third thoracic segment with one seta. Lateral tubercle on first and second abdominal segment with 2 setae 100b lateral tubercle on first and second abdominal segment with 2 setae. Ocular tubercle with one seta.

imitator
Body setae barbulate (fig.5b) (fig.6) (fig.7). Cephalic dorso-external tubercle with 3 setae. Cephalic seta A present (fig.1). Dorso-external and dorsolateral tubercle on second abdominal segment with 2 setae. Dorso-internal tubercles on second thoracic segment with 3 setae. Dorsolateral tubercle and lateral tubercle on fourth abdominal segment fused. Eyes 2 + 2 (fig.4). On fourth abdominal segment tubercle dorsolateral tubercle with setae.

interrogator
Cephalic setae present. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Dorsolateral tubercle on second thoracic segment and third thoracic segment with 3 setae. Ocular tubercle with two setae.

izabalana
Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with two setae. Ocular tubercle with only one seta. Tubercles on third abdominal segment and/or fourth abdominal segment some fused.

iztac
Cephalic dorso-external tubercle with 3 setae. Cephalic seta A absent. Dorso-internal tubercles on second thoracic segment with 3 setae. Ocular tubercle with less than 3 setae. Ocular tubercle with two setae (fig.3b). Thoracic dorso-lateral tubercle with 3 setae.

janssensi
Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with two setae. Ocular tubercle with two setae. Tubercles on third abdominal segment and/or fourth abdominal segment not fused.

macgregori
Cephalic dorso-external tubercle with 3 setae. Cephalic seta A absent. Dorso-internal tubercles on second thoracic segment with 3 setae. Ocular tubercle with less than 3 setae. Ocular tubercle with one seta (fig.3a). Thoracic dorso-lateral tubercle with 3 setae.

medellini
Cephalic dorso-external tubercle with 2 setae. Cephalic seta A absent. Dorso-internal tubercles on second thoracic segment with 3 setae. Thoracic dorso-lateral tubercle with 3 setae.

mexicana
Body setae barbulate (fig.5b) (fig.6) (fig.7). Cephalic dorso-external tubercle with 3 setae. Cephalic seta A present (fig.1). Dorso-external and dorsolateral tubercle on second abdominal segment with 2 setae. Dorso-internal tubercles on second thoracic segment with 3 setae. Dorsolateral tubercle and lateral tubercle on fourth abdominal segment not fused. Eyes 2 + 2 (fig.4). On fourth abdominal segment tubercle dorsolateral tubercle with setae.

nova
Cephalic dorso-external tubercle with 3 setae. Cephalic seta A present (fig.1). Dorso-external and dorsolateral tubercle on second abdominal segment with 3 setae. Dorso-internal tubercles on second thoracic segment with 3 setae. Eyes absent.

palaciosi
Cephalic seta A absent. Dorso-internal tubercles on second thoracic segment with 3 setae. Thoracic dorso-lateral tubercle with 2 setae.

prima
Body setae smooth (fig.5a). Cephalic dorso-external tubercle with 3 setae. Cephalic seta A present (fig.1). Dorso-external and dorsolateral tubercle on second abdominal segment with 2 setae. Dorso-internal tubercles on second thoracic segment with 3 setae. Eyes 2 + 2 (fig.4). On fourth abdominal segment tubercle dorsolateral tubercle without setae.

sardinasensis
Cephalic dorso-external tubercle with 3 setae. Cephalic seta A absent. Dorso-internal tubercles on second thoracic segment with 3 setae. Ocular tubercle with three setae (fig.2). Thoracic dorso-lateral tubercle with 3 setae.

setafoliacea
Cephalic setae absent. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Dorsolateral tubercle on first and second abdominal segment with 1 seta. Dorsolateral tubercle on second thoracic segment and iii with 1 seta. Ocular tubercle with two setae.

sotanophila
Cephalic setae present. Dorso-internal tubercles on second thoracic segment with less than 3 setae. Dorso-internal tubercles on second thoracic segment with only one seta. Dorsolateral tubercle on second thoracic segment and third thoracic segment with 2 setae. Lateral tubercle on second thoracic segment and third thoracic segment with 3 setae. Ocular tubercle with two setae.

unguimitl
Cephalic dorso-external tubercle with 2 setae. Cephalic seta A present (fig.1). Dorso-internal tubercles on second thoracic segment with 3 setae. Ocular tubercle with three setae. Unguis with one tooth.

References