Key to the deutonymphs for the species of Euryparasitus and the genera of Euryparasitidae in North America

1. Some elongate dorsal idiosomal setae (e.g. setae z5, r4, Z3, and/or Z5) rodlike and distinctly plumose .............................................................................. Cyrtolaelaps Berlese

­ All dorsal idiosomal setae, setiform, tapering to a point..... Euryparasitus Oudemans 2

2. Barbed setae on idiosoma absent; serrations on the free, anterior margin of the gnathotectum absent (Fig. 1 A); well differentiated acrotarsus on legs I present.................... 3

­ Barbed setae on idiosoma present (e.g. setae r4, Z5, occasionally s2, r2, Z3) (Figs. 5, 6); serrations on the free, anterior margin of the gnathotectum present (Figs 1 C, 1E); well differentiated acrotarsus on legs I absent .............................................................. 4

3. Median dorsal setae J1­J4 (and most other dorsal setae also) long, surpassing insertion base of the next seta in the series. Euryparasitus longicheta Bondartchuk & Buyakova

­ Median dorsal setae J1­J4 (and most other dorsal setae also) shorter, not surpassing insertion of the next seta in the series ......................... Euryparasitus occidentalis n. sp.

4. Species very large, idiosomal length averaging nearly 1200 µm. Chelicerae with 6 teeth on fixed, 3 on movable digit (Fig. 1 F) ...................... Euryparasitus calcarator (Banks)

­ Species smaller, idiosomal length averaging about 800 µm. Chelicerae with 4 teeth on fixed, 3 on movable digit (Fig. 1 E) ..................................... Euryparasitus maseri n. sp.