Key to world species of Holostaspis (females)

1. Dorsal shield setae J5 and Z5 similar in length; anterolateral angles of anal shield slightly extended, with pointed margins (Figs 33, 57); epistome with well-rounded apex.................................................................. 2

- Dorsal shield setae J5 shorter than Z5 (Z5 = 1.5– 3 x J5); anterolateral angles of anal shield normal, with curved margins (Figs 2, 44); epistome with tapered apex........................................................................ 3

2. Podonotal and opisthonotal setae similar in length, vertical setae (j1) and setae of dorsal hexagon (j5, z5, j6) similar in length; with two unpaired accessory setae between J1 and J3 (Fig. 33)..................... Holostaspis isotricha Kolenati, 1858

- Opisthonotal setae 2–3 times as long as podonotal setae, vertical setae (j1) 1.5 times as long as setae of dorsal hexagon (j5, z5, j6); with one unpaired accessory seta between J3 and J4 (Fig. 57)................. Holostaspis oophila (Wasmann, 1897)

3. Vertical (j1) and clunal setae (Z5) conspicuous, thicker than other dorsal shield setae: j1 longer than other anteromedial setae (j2–j6), Z5 = 3x J5 and Z5 = 2x S5 (J 5 16–21 µm, S 5 24–31 µm, Z5 47–56 µm) (Fig. 44).................................................................................................... Holostaspis montana (Berlese, 1904)

- Vertical (j1) and clunal setae (Z5) not as conspicuous: j1 never longer than other anteromedial setae (j2–j6), and Z5 similar in size to S5 ............................................................................................ 4

4. Poststigmatic section of peritrematal shield notably extended beyond coxa IV, almost reaching anterior margin of metapodal platelet; epigynal shield tapered posteriorly, cuneiform; clunal setae (Z5) relatively short (Z5 <J4)............................................................................ Holostaspis iranica (Babaeian & Nemati, 2014) comb. nov.

- Poststigmatic section of peritrematal shield normal, not extending beyond coxa IV; epigynal shield regularly curved posteriorly, rounded; clunal setae (Z5) relatively long (Z5> J4)....................................................... 5

5. Peritremes shorter, with anterior ends reaching middle of coxa II; no unpaired accessory setae between J1–J5; metapodal platelets conspicuously elongate and narrow............................. Holostaspis michaeli (Joharchi, 2013) comb. nov. [? = Holostaspis acuminata (Berlese, 1903) comb. nov.]

- Peritremes longer, with anterior ends reaching middle of coxa I; at least one unpaired accessory seta between J1–J5; metapodal platelets short and wide, suboval......................................................................... 6

6. Dorsal shield not completely covering dorsal idiosoma, exposing strips of lateral and posterior soft integument (Fig. 19); anal shield (AS) wider than long, markedly distant from epigynal shield (ES) (AS – ES = 1.5– 2 x AS length) (Fig. 21); two posterolateral setae (pl1, pl2) on tibia III and genu III–IV, five ventral setae on femur I (Figs 26–29)....................................................................................... Holostaspis flexuosa (Michael, 1891) comb. nov.

- Dorsal shield completely covering dorsal idiosoma; anal shield longer than wide, close to epigynal shield (AS– ES <0.5 x AS length); one posterolateral seta (pl1) on tibia III and genu III–IV, four ventral setae on femur I........................ 7

7. Dorsal setae shorter: J5 with tips not reaching posterior margin of dorsal shield; J 5 21–26 µm, J 4 25–31 µm (Fig. 1)..................................................................................... Holostaspis ambigua sp. nov.

- Dorsal setae longer: J5 with tips reaching beyond posterior margin of dorsal shield; J 5 29–36 µm, J4 37–41 µm ......... 8

8. Posteromedial dorsal surface with 1–4 unpaired accessory setae; deutosternal groove narrowed posteriorly................................................................................... Holostaspis collina (Huhta & Karg, 2010)

- Posteromedial dorsal surface with a single unpaired accessory seta; deutosternal groove with regular width................................................................... Holostaspis submontana (Bai, Gu & Chen, 1994) comb. nov.