Archisotoma, Linnaniemi, 1912

Araujo De Lima, Estevam C., Zeppelini, Douglas & Mendonça, Maria Cleide De, 2019, Brazilian Archisotoma Linnaniemi (Collembola, Isotomidae), with description of a new species from an oceanic atoll, Zootaxa 4543 (1) : -

Key for the identification of the species of the genus Archisotoma

(modified from Thibaud & Palacios-Vargas 2001)

Number in parenthesis refers to Good’s Biogeographic zone ( Good 1974; Culik & Zeppelini 2003).

1 Manubrium with chaetae................................................................................ 2 - Manubrium without chaetae......................................... A. pauliani Delamare Debouteville, 1953 (15) 2 PAO long, 6 times longer than the closest eye....................................... A. nigricans Bagnall, 1939 (2a) - PAO normal, 2–4 times longer than the closest eye........................................................... 3 3 Eyes absent; Abd. V and VI without trichobothria....................... A. heraultensis Christian & Thibaud, 1996 (2a) - Eyes present; Abd. V and VI with 2 or 3 pairs of trichobothria.................................................. 4 4 Three pairs of trichobothria (ta., tm., tl.), in almost transversal position, 1 chaeta between ta. and tm................... 5 - Two pairs of trichobothria (ta., tp.), in almost diagonal position, 2 or 3 chaetae between ta. and tp...................... 15 5 PAO at maximum 2 times longer than the closest eye.................... A. subthea Thibaud & Boumezzough, 2006 (5) - PAO normal, 2–4 times longer than the closest eye........................................................... 6 6 Tita. III with dorso-apical spine.......................................................................... 7 - Tita. III without dorso-apical spine....................................................................... 12 7 8 +8 eyes, 2 of them often reduced; dens elongated with at least 10 chaetae....................................... 8 - 2+2 eyes; dens short with 3 chaetae..................................... A. quadrioculata Fjellberg, 1988 (1 and 2a) 8 12 prelabral chaetae................................................... A. brucei Carpenter, 1907 (15, 35 and 37) - At most 5 prelabral chaetae.............................................................................. 9

9 Dens with 10–12 chaetae; 2 prelabral chaetae.............................................................. 10

- Dens with more than 25 chaetae; 4–5 prelabral chaetae....................................................... 11

10 Manubrium with 18 posterior chaetae; mucro with 1 chaeta................... A. martae, Fjellberg & Juceviča, 2000 (2a)

- Manubrium with about 10 posterior chaetae; mucro without chaeta................... A. theae Fjellberg, 1980 (1 and 2a)

11 Body length 0.5 mm; manubrium with ~20 chaetae; dens with 36 chaetae.................. A. poinsotae Gama, 1968 (2a)

- Body length 1.0–1.5 mm; manubrium with ~32 chaetae; dens with 26–30 chaetae................................................................................................. A. besselsi Packard, 1877 (1, 2a, 5, 8, 24a and 27)

12 At least six prelabral chaetae............................................................................ 13

- Two prelabral chaetae................................................... A. pulchella Moniez, 1889 (2a, 4 and 5)

13 6–9 prelabral chaetae.................................................................................. 14

- 20 prelabral chaetae..................................................... A. megalops Bagnall, 1939 (1, 2a and 5)

14 Head with 6–7 frontal chaetae; PAO 2.9 times longer than anterior eye............ A. polaris Fjellberg & Poinsot, 1975 (1)

- Head with 8–9 frontal chaetae; PAO 1.8 times longer than anterior eye....... A. vareli Sterzyńska & Ehrnsberger, 2000 (2a)

15 Body length ~0.5 mm; 2 prelabral chaetae; ventral tube with 4+4 chaetae........................................ 16

- Body length ~ 1 mm; 4 prelabral chaetae in 2 rows; ventral tube with 4 or 6 chaetae on each side...................... 26

16 3+3 eyes............................................. A. madagascariensis Thibaud, 2008 (15) (in: Thibaud 2008a)

- 4+4 or more eyes..................................................................................... 17

17 4+4 eyes...................................................................... A. mayotti Thibaud, 2010 (17)

- 5+5 or more eyes..................................................................................... 18

18 5+5 eyes, 2 of them reduced....................................................... A. sabulosa Barra, 1997 (14)

- 6+6 or more eyes..................................................................................... 19

19 Manubrium with 10–14 posterior chaetae.................................................................. 20

- Manubrium with more than 14 posterior chaetae............................................................ 21

20 6+6 eyes........................................................... A. arariboia Neves & Mendonça, 2014 (27)

- 8+8 eyes........................................................................... A. jariani sp. nov. (27)

21 Ta. and tp. of the same length................................... A. bothrilongaequalis Thibaud & Ndiaye, 2006 (10)

- Ta. usually longer than tp............................................................................... 22

22 Two chaetae between ta. and tp....................................... A. senegalensis Thibaud & Ndiaye, 2006 (10)

- At least 3 chaetae betwen ta. and tp....................................................................... 23

23 Five or six chaetae between trichobothria ta................................................................ 24

- Two or three chaetae between trichobothria ta................................ A. litoralis Thibaud & Weiner, 1997 (21)

24 Dens with 18 chaetae; anterior subcoxa furcalis with 13–17 chaetae; posterior subcoxa furcalis with 11–14 chaetae....... 25

- Dens with 20–24 chaetae; anterior subcoxa furcalis with 19–21chaetae; posterior subcoxa furcalis with 15–18 chaetae........................................................................ A. gourbaultae Thibaud, 1993 (24b and 27)

25 Axial chaetotaxy Th. II–Abd. I: 8,5/4............................. A. vaoensis Thibaud & Weiner, 1997 (15, 18 and 21)

- Axial chaetotaxy Th. II-Abd. I: 7,5/3.................................... A. catiae Abrantes & Mendonça, 2007 (27)

26 Body length 0.8–1.1 mm; manubrium with ~20–30 posterior chaetae; dens with ~20–30 chaetae; ventral tube with 4+4 chaetae................................ A. interstitialis Delamare Deboutteville, 1953 (2a, 3a, 4, 5, 8, 13, 24a, 24b, 32 and 34)

- Body length 1.0–1.5 mm; manubrium with ~20 chaetae; dens with ~40 chaetae; ventral tube with 6+6 chaetae............................................................................................ A. utinomii Yosii, 1971 (3a)