Key for the world species of Typhloseiopsis

1. Seta S2 present......................................................... T. adventitius Ferragut & Moraes n. sp.

- Seta S2 absent........................................................................................2

2. Female with ventrianal shield...................................................... T. funiculatus De Leon, 1965

- Female either with separate ventral and anal shields, or without ventral shield......................................3

3. Female with separate ventral and anal shields...............................................................4

- Female without ventral shield............................................................................5

4. Calyx of spermatheca funnel-shaped........................................ T. neopritchardi Moraes & Mesa, 1988

- Calyx of spermatheca short-saccular........................................... T. pritchardi (Chant & Baker, 1965)

5. Calyx of spermatheca tubular, about 5 times as long as its diameter; minor duct indistinct........ T. maryae McMurtry, 1983

- Calyx of spermatheca slender, 20–25 times as long as its diameter; minor duct distinct, giving the impression of subdivided calyx....................................................................... T. theodoliticus De Leon, 1959