Key to females of Pseudotarsonemoides (after Smiley & Moser 1974, with modifications)

1. Dorsal idiosoma without conspicuous longitudinal ridges..................................................... 4

- Dorsal idiosoma with conspicuous longitudinal ridges........................................................ 2

2. Setae e and h subequal................................................................................. 3

- Setae e more than twice longer than h .............................................. P. longisetus Khaustov, 1998

3. Idiosoma almost three times longer than wide, stigmata located near lateral margin of prodorsal shield............................................................................................. P. vermiformes Khaustov, 1998

- Idiosoma about two times longer than wide, stigmata located far from lateral margin of prodorsal shield........................................................................................... P. innumerabilis Vitzthum, 1923

4. Solenidion φ 2 present, tegula approximately equal in length and width........................................... 5

- Solenidion φ 2 absent, tegula almost two times longer than wide................................. P. peruviensis n. sp.

5. Setae e several times longer than f ....................................................................... 6

- Setae e and f subequal........................................................... P. pteleobii Cooreman, 1963

6. Dorsal hysterosomal setae smooth....................................................................... 7

- Dorsal hysterosomal setae barbed............................................... P. scolyti Smiley & Moser, 1974

7. Tibia III without sclerotized notches...................................................................... 8

- Tibia III with sclerotized notches........................................... P. americanus Smiley & Moser, 1974

8. Idiosoma long and slender, about 2.4 times longer than wide, trichobothria globe-like, or, trachea long and slender................................................................................. P. fechteri Smiley & Moser, 1974

- Idiosoma short and oval, about 1.8 times longer than wide, trichobothria ellipsoidal, trachea long and stout....................................................................................... P. eccoptogasteris Vitzthum, 1921