Key to Tenuipalpidae on Cyperaceae in Australia

1. Dorsal opisthosomal setae c1, d1 present, setae e1 absent (Figs 2, 9, 12, 20); genua I – IV nude....................... 2

- Dorsal opisthosomal setae c1 absent, setae d1, e1 present (Figs 22 – 25); genua I – II with setae, genu III with or without setae..................................................................................................... 5

2. Dorsal opisthosomal setae e2 absent, setae e3, f2, f3 present (Figs 2, 9); trochanters I – IV with one seta (v’); anterior margin of prodorsum without projections.................................................. 3 Gahniacarus Beard & Ochoa

- Dorsal opisthosomal setae e2, f3 absent, setae e3, f2 present (Figs 12, 20); trochanters I – IV nude (except male tr I with one seta, v’); anterior margin of prodorsum with three projections (a pair of conical projections (each bearing setae v2) flanking a broad median projection)...................................................... 4 Cyperacarus Beard & Ochoa

3. Prodorsal setae sc1 elongate, obviously longer than most other dorsal setae (Fig. 9); protonymph with dorsal opisthosomal setae e3 minute (Fig. 11).................................................. Gahniacarus gersonus Beard & Ochoa

- Prodorsal setae sc1 subequal in length to other dorsal setae (Fig. 2); protonymph with dorsal opisthosomal setae e3 subequal to other dorsal setae, barbed (Fig. 7)....................................... Gahniacarus tuberculatus Beard & Ochoa

4. Dorsal opisthosomal setae c1 minute (Fig. 20); lateral dorsal opisthosomal setae broadly rounded distally; prodorsal setae sc2> 240 μm............................................................... Cyperacarus foliatus Beard & Ochoa

- Dorsal opisthosomal setae c1 short, broad, barbed (Fig. 12); lateral dorsal opisthosomal setae tapered distally; prodorsal setae sc2 <220 μm............................................................ Cyperacarus naomae Beard & Ochoa

5. Anterior margin prodorsum smooth, or with a reduced median projection (Figs 22, 23); genu III nude.............................................................................................. 6 Prolixus Beard, Fan & Walter

- Anterior margin prodorsum with elongate, divided median projection (Figs 24, 25); genu III with one seta (d)............................................................................................ 7 Acaricis Beard & Gerson

6. Dorsal opisthosomal setae f2 present (Fig. 22); dorsal opisthosomal setae d1, c3 equal in length, short; dorsum with apparent prodorsal and opisthosomal shields, plicate between sc2–d1....................... Prolixus forsteri Beard, Fan & Walter

- Dorsal opisthosomal setae f2 absent (Fig. 23); dorsal opisthosomal setae c3 obviously longer than d1; dorsum entirely plicate................................................................... Prolixus corruginus Beard, Fan & Walter

7. Setae sc2 broadly lanceolate, finely barbed, longer than sc1 (Fig. 24); femur III with seta d broadly lanceolate, finely barbed............................................................................ Acaricis plana Beard & Gerson

- Setae sc2 short, barbed, equal in length to sc1 (Fig. 25); femur III with seta d short, stout, smooth................................................................................................ Acaricis danutae Beard & Gerson