Steatonyssus, Kolenati, 1858

Orlova, Maria V. & Anisimov, Nikolay V., 2023, Three new species of bat-parasitic gamasid mites of the genera Spinturnix, Macronyssus and Steatonyssus (Acari: Mesostigmata: Spinturnicidae, Macronyssidae) from Siberia and Mongolia, with keys to species of Russia and adjacent countries, Persian Journal of Acarology 12 (2), pp. 211-239 : 231

Key to species of the genus Steatonyssus of Russia and adjacent countries (females)

1. Setae Z5 on opisthosomal plate long.............................................................................................. 2

– Setae Z5 short ................................................................................................................................ 3

2. Setae Z5 1.5 – 2.0 times shorter than J1–3 ........................................... S. spinosus Willmann, 1936

– Setae Z5 and J1–3 equal ............................................................................. S. noctulus Rybin, 1992

3. Peritremes long, reaching posterior margin or middle of coxa II ................................................. 4

– Peritremes short, not reaching posterior margin of coxa II ........................................................... 5

4. Setae St1–3 subequal; posterior end of opisthonotal plate with three pairs of short, subequal setae S4, S5, Z5; J5 microsetae .............................................................................................................. 6

– Setae St 1 2 times shorter than St 3; posterior end of opisthonotal plate with setae S5 approximately 3 times longer than S4 and Z5; J5 short .......................................... S. mongolicus Dusbabek, 1966

5. Peritremes reaching middle of coxae III; sternal plate with a well sclerotized posterior margin .... ................................................................................................ S. occidentalis evansi (Ewing, 1933)

– Peritremes nearly reaching anterior margin of coxa III; sternal plate with a weakly sclerotized band ................................................................................................................. S. desertorus Rybin, 1992

6. Setae St1 very short, nearly three times shorter than St3 ............... S. periblepharus Kolenati, 1858

– Setae St1 slightly shorter then St3 .................................................................................................. 7

7. Posterior end of body with 10 – 12 pairs of thick, knife-shaped setae .............................................. ............................................................................................................ S. superans Zemskaya, 1951

– Thick, knife-shaped setae absent.................................................................................................... 8

8. Peritremes reaching middle of coxae II; anterodorsal spur on coxa II with five denticles (sometimes difficult to observe); setae S 4–5 and Z5 subequal .......................... S. aglaiae Stanjukovich, 1991

– Peritremes reaching posterior margin of coxae II ......................................................................... 9

9. Setae j3 short, 1/2 of length of j1 .................................................................. S. cavus Rybin, 1992

– Setae j3 longer ............................................................................................................................. 10

10. Dorsal unsclerotized cuticle with more than 50 pairs of setae ....................................................... ....................................................................................... S. heteroventralis Ah & Radovsky, 1967

– Dorsal unsclerotized cuticle with about 30 pairs of setae .............................................................. .................................................................................................. S. pseudoheteroventralis sp. nov.