Ptenothrix, Borner, 1906

Jo, Seon Hwa & Park, Kyung-Hwa, 2023, A new species of Ptenothrix Börner, 1906 (Collembola, Symphypleona, Dicyrtomidae) from South Korea, Zootaxa 5301 (1), pp. 124-136 : 134-135

Key to the East Asian species of Ptenothrix *

1 Dorsal anal valve mps1–3 and ventral anal valve mpi1–2 chaetae mostly ciliated.................................. 2

- Dorsal anal valve mps1–3 and ventral anal valve mpi1–2 chaetae not ciliated..................................... 5

2 Dorsal anal valve ms1 chaeta blunt acanthoid............................................................... 3

- Dorsal anal valve ms1 chaeta regular pointed............................................................... 4

3 Dorsal anal valve ms1 chaeta longer than ms2; ventral anal valve pi1 chaeta longer than pi2 ...... P. vittata ( Folsom, 1896)

- Dorsal anal valve ms1 chaeta shorter than ms2; ventral anal valve pi1 chaeta as long as pi2 ....... P. mongolica Yosii, 1954

4 Dorsal anal valve mps’ chaeta blunt acanthoid; dorsal anal valve ps1 shorter than ps2; dorsal anal valve ms4 chaeta as long as mps4 ....................................................................... P. ciliophora Yosii & Lee, 1963

- Dorsal anal valve mps' chaeta regular pointed; dorsal anal valve ps1 as long as ps2; dorsal anal valve ms4 chaeta much longer than mps4 .................................................................... P. saxatilis Yosii & Lee, 1963

5 Dorsal anal valve ps1 chaeta regular pointed................................................................ 6

- Dorsal anal valve ps1 chaeta blunt acanthoid.......................................... P. higashihirajii Yosii, 1965

6 Ventral anal valve mi5 regular pointed; clypeal median area chaetae mostly regular pointed.......................... 7

- Ventral anal valve mi5 blunt acanthoid; clypeal median area chaetae mostly blunt acanthoid......................... 10

7 Clypeal median area chaetae following the formula: 1, 1, 2, 1, 1, 3 .............................................. 8

- Clypeal median area chaetae following another formula....................................................... 9

8 Ventral anal valve pi1 chaeta as long as pi2; manubrium with 10+10 dorsal chaetae......... P. plumiseta Kang & Lee, 2005

- Ventral anal valve pi1 chaeta shorter than pi2; manubrium with 9+9 dorsal chaetae................ P. higumai Yosii, 1965

9 Dorsal anal valve ms2 chaeta regular pointed; ventral anal valve pi3 chaeta shorter than mi5; Abd. VI dorsally with 1+1 roundish white spots............................................................. P. setosa ( Krausbauer, 1898)

- Dorsal anal valve ms2 chaeta blunt acanthoid; ventral anal valve pi3 chaeta as long as mi5; Abd. VI dorsally without white spots............................................................................. P. janthina Börner, 1909

10 Dorsal anal valve ps1 chaeta as long as ps2 ................................................................ 11

- Dorsal anal valve ps1 chaeta longer than ps2 .............................................................. 12

11 Clypeal median area chaetae formula as: 1, 1, 2, 2, 1, 3; manubrium with 7+7 dorsal chaetae; head with a transversal black band......................................................................... P. corynophora Börner, 1909

- Clypeal median area chaetae formula as: 1, 1, 2, 2, 1, 1; manubrium with 8+8 dorsal chaetae; head without a transversal black band........................................................... P. huangshanensis Chen & Christiansen, 1996

12 Ventral anal valve mi5 chaeta thin acanthoid............................................................... 13

- Ventral anal valve mi5 chaeta blunt acanthoid.............................................................. 14

13 Clypeal median area chaetae formula as: 1, 1, 2, 2, 1, 1; ventral anal valve pi1 chaeta as long as pi2 ............................................................................................. P. monochroma Yosii & Lee, 1963

- Clypeal median area chaetae with formula as: 1, 1, 2, 2, 1, 3; ventral anal valve pi1 chaeta shorter than pi2 ............................................................................................. P. yakushimana Yosii, 1965

14 Dorsal anal valve ms1 chaeta as long as ms2 .............................................................. 15

- Dorsal anal valve ms1 chaeta longer or shorter than ms2 ..................................................... 16 15 Frontal chaeta a shorter than b; large abdomen dorsally with a purple cross band............ P. denticulata ( Folsom, 1899)

- Frontal chaeta a slightly longer than b; large abdomen dorsally without a purple cross band.......... P. tsutsuii Yosii, 1955

16 Dorsal anal valve ms1 chaeta shorter than ms2; frontal chaeta a much longer than b ......... P. marmorata ( Packard, 1873)

- Dorsal anal valve ms1 chaeta much longer than ms2; frontal chaeta a slightly longer than b .. Ptenothrix koreanensis sp. nov.