Key to the Cheiroseius species recorded from Brazil (based on females)

1. Peritreme extending posteriorly beyond stigma, curving inward behind coxa IV................................... 2

- Peritreme extending or not posteriorly beyond stigma, never curved behind coxa IV.................................5

2. Ventrianal shield with four pairs of opisthogastric setae in addition to circumanals; leg I at most 250 long............................................................................................ Cheiroseius brevipes Karg, 1977

- Ventrianal shield with 2–3 pairs of opisthogastric setae in addition to circumanals; leg I at least 330 long................3

3. Ventrianal shield with two pairs of opisthogastric setae in addition to circumanals; dorsal shield smooth; without metapodal platelets..................................................................... Cheiroseius luizgonzagai n. sp.

- Ventrianal shield with three pairs of opisthogastric setae in addition to circumanals; dorsal shield ornamented; with a pair of metapodal platelets....................................................................................4

4. Dorsal shield ornamented with a network of ridges and depressions; leg I about 360 long...... Cheiroseius xerophilus n. sp.

- Dorsal shield ornamented with minute punctuation; leg I about 800 long.... Cheiroseius tuberculatus (Evans & Hyatt, 1960)

5. Dorsal shield with lateral incisions (between setae S 2 and S 3); reticulate pattern of dorsal shield formed by lines of tubercles................................................................... Cheiroseius ornatus (Evans & Hyatt, 1960)

– Dorsal shield without lateral incisions; ornamentation of dorsal shield not constituted by lines of tubercles...............6

6. Tarsus I without claws; most of dorsal setae dagger-like........................... Cheiroseius pugiunculus Karg, 2006

- Tarsus I with claws; most of dorsal setae aciculate............................................................7

7. Anteromedian extension of epistome distally truncate and with denticles, slightly longer than anterolateral extensions............................................................................. Cheiroseius parvipulmonis Karg, 1977

- Anteromedian extension of epistome tapering distally and/or much longer than anterolateral extensions.................8

8. Peritreme extending posteriorly beyond stigma by an extension distinctly longer than its width immediately anteriad of stigma.................................................................. Cheiroseius tennesseensis (De Leon, 1964)

- Peritreme not extending posteriorly beyond stigma or extending by a very short extension............................................................................ Cheiroseius neophalangioides Mineiro, Lindquist & Moraes, 2009