Xenylla, , Tullberg, 1869

Sternalski, Jakub & Paśnik, Grzegorz, 2019, A new species of Xenylla Tullberg, 1869 (Collembola: Hypogastruridae) from Peru, with a key to Neotropical species of the genus, Zootaxa 4711 (1), pp. 185-192 : 187-188

Key to the Neotropical species of the genus Xenylla

1 Furca absent......................................................................................... 2

- Furca present........................................................................................ 4

2 Head with dorsal setae c1 and c2 present.................. X. atrata ( Salmon, 1944) (New Zeland, Argentina, Venezuela)

- Head with dorsal setae c1 present and c2 absent............................................................. 3

3 Head with dorsal setae l1 and l3 subequal in length................................................................ X. subacauda Stebaeva & Potapov, 1994 in: Babenko, Chernova, Potapov & Stebaeva, 1994 ( Russia, Poland, Mexico)

- Head with dorsal setae l1 shorter than l3................................................................................. X. acauda Gisin, 1947 ( Switzerland, Austria, Spain, Great Britain, Poland, Russia, USA, Mexico, Venezuela)

4 Mucro absent.............. X. boerneri Axelson, 1905 ( Russia, Ukraine, Lativia, Finland, Austria, Switzerland, England)

- Mucro present........................................................................................ 5

5 Mucro seprated from dens.............................................................................. 6

- Mucro fused to dens.................................................................................. 23

6 Head with 4+4 ocelli....................................................................................... X. yucatana Mills, 1938 ( Solomon Islands, Mexico, Sudan, Jamaica, Porto Rico, Thailand, Gabon, Gambie, Singapour, Brasil, Ecuador, West Indies, Galapagos)

- Head with 5+5 ocelli.................................................................................. 7

7 Dens with one seta, retinaculum with 2+2 teeth.............................................................. 8

- Dens with two setae, retinaculum with 3+3 teeth............................................................. 9

8 Tibiotarsi with 0,1,1 tenent hairs respectively.................................... X. saludoi Izarra, 1970 ( Argentina)

- Tibiotarsi with 2,2,2 tenent hairs respectively............................... X. canadensis Hammer, 1953 ( Canada) *

9 Ant. IV with 4 thick sensilla............................................................................ 10

- Ant. IV with 5–6 thick sensilla.......................................................................... 19

10 Tibiotarsus of first leg with 1 clavate tenent hair............................................................ 11

- Tibiotarsus of first leg with 2 clavate tenent hairs........................................................... 13

11 Tibiotarsi with 1,2,2 tenent hairs respectively...................................................................... X. welchi Folsom, 1916 ( USA, Solomon Islands, Sudan, Pakistan, Singapour, Taiwan, Jamaica, Hawaii, Brasil, South Australia, Argentina, Chile, Peru, West Indies, French Guiana, Cuba)

- Tibiotarsi with 1,1,1 tenent hairs respectively.............................................................. 12

12 Head with dorsal setae l1 and l3 subequal in length......................... X. portoricensis Gama, 1976 ( Porto Rico)

- Head with dorsal seta l3 longer than l1........................................ X. bellingeri Gama, 1969 ( Jamaica)

13 Claw without inner tooth............................................ X. hodori Neves & Mendonça, 2017 ( Brasil)

- Claw with inner tooth present........................................................................... 14

14 Head with dorsal seta l1 longer than l3................................................................... 15

- Head with dorsal setae l1 and l3 subequal in length......................................................... 16

15 Abd. I–III with seta p5 present.............................................. X. fernandesi Gama, 1974 ( Portugal)

- Abd. I–III with seta p5 absent.................................... X. manuelae Queiroz & Mendonça, 2016 ( Brasil)

16 Head with dorsal seta c2 absent.............................................................................. X. mucronata Axelson, 1903 ( Sweden, Austria, Germany, England, Ukraine, Russia, Siberia, Costa Rica, Peru, Australia)

- Head with dorsal seta c2 present........................................................................ 17

17 Th. II–III with seta p2 aligned with seta p1......................................................................................... X. humicola ( Fabricius, 1780) ( Greenland, Central America, West Indies, Chile, Mexico, Cuba)

- Th. II–III with seta p2 displaced......................................................................... 18

18 Tibiotarsus of legs I–III with 19,19,18 setae respectively.............................. X. gwiazdowiczi sp. nov. ( Peru)

- Tibiotarsus of legs I–III with 17,17,16 setae respectively................. X. spinosissima Najt & Rubio, 1978 (Falkland)

19 Tibiotarsus of first leg with 1 clavate tenent hair............................................................ 20

- Tibiotarsus of first leg with 2 clavate tenent hairs........................................................... 22

20 Tibiotarsi with 1,2,2 tenent hairs respectively, head with dorsal seta l1 longer than l3............................................................................................... X. wandae Queiroz & Mendonça, 2016 ( Brasil)

- Tibiotarsi with 1,1,1 tenent hairs respectively, head with dorsal setae l1 and l3 subequal in length..................... 21

21 Ant. IV with 5 thick sensilla, head with dorsal seta c1 present... X. raynalae Najt, Thibaud & Weiner, 1990 ( French Guiana)

- Ant. IV with 6 thick sensilla, head with dorsal seta c1 absent................... X. nirae Gama & Oliveira, 1994 ( Brasil)

22 Mucro with apical globe present, Abd. IV without setae m1................................................................................................. X. villiersi Thibaud, 1963 ( Ivory Coast, Angola, Gambie, Martinique)

- Mucro without apical globe, Abd. IV with setae m1.................. X. capixaba Fernandes & Mendonça, 2010 ( Brasil)

23 Dens with 2 setae.................................................................................... 24

- Dens with 1 seta..................................................................................... 29

24 Tibiotarsi with 1,1,1 tenent hairs respectively.............................................................. 25

- Tibiotarsi with 2,2,2 tenent hairs respectively.............................................................. 26

25 Retinaculum with 2+2 teeth.................................................. X. brasiliensis Gama, 1978 ( Brasil)

- Retinaculum with 3+3 teeth.............................................. X. subbellingeri Gama, 1976 ( Trinidad)

26 Ant. IV with 5 thick sensilla................................................... X. simberloffi Gama, 1974 ( USA)

- Ant. IV with 4 thick sensilla............................................................................ 27

27 Head with dorsal setae l1 and l3 subequal in length......... X. jamaicensis Gama, 1969 ( Jamaica, Guadalupe, Martinique)

- Head with dorsal seta l1 longer than l3................................................................... 28

28 Dorsal body s-chaetae longer than regular setae............. X. maritima Tullberg, 1869 (Scandinavia, Brasil, Venezuela)

- Dorsal body s-chaetae and regular setae subequal in size................................................................. X. grisea Axelson, 1900 ( Finland, RSA, England, Saint Helen Island, Belgium, Hawaii, USA, Chile, Porto Rico)

29 Retinaculum with 3+3 teeth............................................................................ 30

- Retinaculum with 2+2 teeth............................................................................ 32

30 Head with dorsal seta c1 absent.................................. X. capitata Thibaud & Massoud, 1980 ( Guadalupe)

- Head with dorsal seta c1 present........................................................................ 31

31 Body with scattered pigment, colour blue-grey. X. cavernarum Jackson, 1927 ( Trinidad, Jamaica, Solmon Islands, Argentina)

- Body without pigment, only eyes pigmented................................. X. subcavernarum Gama, 1969 ( Brasil)

32 Claw without inner tooth................................................... X. duchesnea Wray, 1958 ( Mexico)

- Claw with inner tooth present........................................................................... 33

33 Anal spines setiform, straight and slender.................................... X. christianseni Gama, 1974 ( Mexico)

- Anal spines short on papillae........................................................................... 34

34 Mucro without lamella.............................. X. proxima Denis, 1931 ( USA, Costa Rica, Guadelupa, Mexico)

- Mucro with lamella................................................................................... 35

35 Head with dorsal seta l1 shorter than l3............................... X. tullbergi Börner, 1903 (Europe, Switzerland)

- Head with dorsal seta l1 longer than l3................................................................... 36

36 Head with dorsal seta c1 present, Abd. IV with setae m1............................... X. wilsoni Gama, 1974 ( USA)

- Head with dorsal seta c1 absent, Abd. IV without setae m1................ X. uniseta Gama, 1963 (Dalmatie, Yugoslavia)