Pentamerismus, McGregor, 1949

Mirza, Jawwad Hassan, Elgoni, Nasreldeen Ahmed, Kamran, Muhammad & Alatawi, Fahad Jaber, 2025, Subgenera of the genus Pentamerismus McGregor (Acari: Tenuipalpidae) with the re-description of Pentamerismus retusus Meyer and a key to species of the world, Zootaxa 5601 (1), pp. 143-156 : 153-154

Key to subgenera and species of Pentamerismus of the world

1. Dorsal opisthosomal setae f 2 absent. Subgenus Pentamerismus (Oligomerismus) Mitrofanov, 1973 ................... 2

- Dorsal opisthosomal setae f 2 present. Subgenus Pentamerismus (Pentamerismus) McGregor, 1949 .................. 11

2. Dorsal opisthosoma with dorsolateral setae c 2 and d 2 setiform.................................................. 3

- Dorsal opisthosoma with dorsolateral setae c 2 and d 2 lanceolate to spatulate....................................... 5

3. Dorsal propodosoma with small medial notch forming a pair of lobes anterior to setae v 2 ......... P. (O.) taxi ( Haller, 1877)

- Dorsal propodosoma with anterior margin without pair of lobes................................................ 4

4. Dorsal idiosoma entirely striate, dorsolateral (c 3, d 3, e 2, e 3, f 3, h 2 and h 1) setae long................................................................................................. P. (O.) tauricus Livshitz & Mitrofanov, 1970

- Dorsal idiosoma reticulate, dorsolateral setae (c 3, d 3, e 2, e 3, f 3, h 2 and h 1) short.................................................................................................. P. (O.) coronatus ( Canestrini & Fanzago, 1876)

5. Dorsal opisthosomal setae c 1, d 1, e 1 minute, setiform......................................................... 6

- Dorsal opisthosomal setae c 1, d 1, e 1 lanceolate to spatulate.................................................... 10

6. Either or both dorsal propodosoma and opisthosoma with reticulations.......................................... 7

- Dorsal opisthosoma with lineate cuticle................................................................... 8

7. Dorsal idiosoma cuticle completely reticulate............................ P. (O.) ossianensis Thewke & Enns, 1971

- Dorsal propodosoma and dorsal opisthosoma each with only a small medial region of reticulation.............................................................................................. P. (O.) judiciarius De Leon, 1961

8. Genu I and II with two setae......................................... P. (O.) shandongensis ( Wang & Ma, 1993)

- Genu I and II with three setae........................................................................... 9

9. Palp tibia with one seta................................................... P. (O.) canadensis McGregor, 1949

- Palp tibia with two setae.................................................. P. (O.) oregonensis McGregor, 1949

10. Dorsal propodosoma medially reticulated.......................................... P. (O.) foetidae ( Meyer, 1979)

- Dorsal propodosoma medially striated or rugose...................................... P. (O.) retusus Meyer, 1979

11. Dorsal opisthosomal setae setiform...................................................................... 14

- Dorsal opisthosomal setae broadly lanceolate to spatulate.................................................... 12

12. Genital and pseudanal setae broadly lanceolate and heavily barbed............... P. (P.) sititoris Beard & Seeman, 2014

- Gential and pseudanal setae fine, setiform and weakly barbed................................................. 13

13. Palp tibia with two setae, dorsal cuticle weakly reticulated........................ P. (P.) wardo Seeman & Beard, 2014

- Palp tibia with one seta, dorsal cuticle strongly reticulated................ P. (P.) hicklingorum Seeman & Beard, 2014

14. Femora I–II with three setae............................................ P. (P.) kunmingensis Ma & Yaun, 1980

- Femora I–II with four setae............................................................................ 15

15. Anterior margin of dorsal propodosoma shallowly notched................................................... 16

- Anterior margin of dorsal propodosoma deeply notched..................................................... 17

16. Palp femur with one seta; dorsal propodosomal setae slender.................... P. (P.) arbutusae Baker & Tuttle, 1987

- Palp femur without seta; propodosomal setae spatulate or leaf like............... P. (P.) abnormis Baker & Tuttle, 1987

17. Dorsal propodosomal setae setiform................................. P. (P.) ueckermanni Khanjani & Gotoh, 2008

- Propodosomal setae spatulate or leaf like................................................................. 18

18. Dorsal propodosoma medially smooth................................ P. (P.) behsharicus Khanjani & Gotoh, 2008

- Dorsal propodosoma medially rugose lineate, reticulate striated............................................... 19

19. Dorsal propodosoma completely reticulate-rugose.......................................................... 20

- Dorsal propodosoma irregular lineate.................................................................... 21

20. Dorsal opisthosomal setae c 2 setiform............................................ P. (P.) erythreus ( Ewing, 1917)

- Dorsal opisthosomal setae c 2 lanceolate................................ P. (P.) bahaensis Alatawi & Kamran, 2015

21. Dorsal opisthosomal seta c 2 setiform................................................. P. (P.) juniperi Reck, 1951

- Dorsal opisthosomal seta c 2 lanceolate................................ P. (P.) foliisetis Livshitz & Mitrofanov, 1967