Mesostigmata

t

Taxonomy

updated 2025

Diagnostic characters

• Dorsal shield well sclerotized, entire or incised, ornamented with tubercles and bearing <25 pairs of often elongate, thickened and barbed setae, setae J5 absent
• Sternal shield often reduced to 2 pairs of setae, st3 on shield or on platelets
• Corniculi distally toothed, chisel-like, or weakly membranous
• Chelicerae with membranous lobe
• Tectum simple, smoothly subtriangular to acuminate, often with a well-developed median spine
• Genu II with 2 ventral setae
• Palp apotele 3-tined
• Tarsus I with claws and empodium

Similar taxa

Within the Ameroseiidae, species of Epicriopsis are most likely to be confused with those in Ameroseius that have relatively long setae; however, species of Ameroseius have 29 pairs of setae on the dorsal shield, as opposed to 24 or fewer in Epicriopsis. Dorsal shield hypotrichy is also present and tubercular ornamentation is also characteristic of Podocinidae and Epicriidae.

Key to adult females of soil/nest inhabiting genera

1. Dorsal shield with marginal ring of tubercles bearing setae j5, z2, z4, z6, s5, Z2, and S5; forest litter in eastern Australia.............................. Asperolaelaps
   - Not as above.............................. 2

2. Sternal shield with 3 cog-lkie circular ornaments; dorsal shield setae short, club-shaped to spatulate; setae j1 on bifid vertex.............................. Seritympanum
   - Not as above.............................. 3

3. Pretarsus I without claws.............................. Ameroseiella
   - Pretarsus I with claws.............................. 4

4. Dorsal shield with 24 or fewer pairs of setae.............................. Epicriopsis
   - Dorsal shield with 27–29 pairs of setae.............................. 5

5. Dorsal shield with 27 pairs of setae; genu II without ventral setae.............................. Brontispalaelaps
   - Dorsal shield with 29 pairs of setae; genu II with 2 ventral setae.............................. 6

6. Anal shield with 3 setae; genu III with 1 pl seta; palp apotele 3-tined.............................. Ameroseius
   - Ventrianal shield with 5 or more setae; genu III with 2 pl seta; palp apotele 2-tined.............................. Kleemannia

Ecology and distribution

Epicriopsis walteri Halliday lives in rainforest floor litter in Australia and can be reared on fungal hyphae. Other species are found in a variety of litter types and are assumed to be fungivores.

References

• Elsen and Whitaker 1985Elsen and Whitaker 1985:
  Elsen P, Whitaker JO, Jr. 1985. Seritympanum, a new genus of Ameroseiidae (Acarina, Mesostigmata) taken from rodents in the United States: including descriptions of three new species in the genus. Acarologia 26: 117–122.
• Evans 1963Evans 1963:
  Evans GO. 1963. The genus Neocypholaelaps Vitzthum (Acari: Mesostigmata). Annals and Magazine of Natural History (13th ser.) 6: 209–230.
• Halliday 1997aHalliday 1997a:
  Halliday RB. 1997a. Revision of the Australian Ameroseiidae (Acarina: Mesostigmata). Invertebrate Taxonomy 10: 179–201.
• Hughes 1976Hughes 1976:
  Hughes AM. 1976. The Mites of Stored Food and Houses (2nd ed.). Ministry of Agriculture, Fisheries and Food, Technical Bulletin 9. Her Majesty's Stationery Office, London.
• Seeman 1996Seeman 1996:
  Seeman OD. 1996. Flower mites and phoresy: The biology of Hattena panopla Domrow and Hattena cometis Domrow (Acari: Mesostigmata: Ameroseiidae). Australian Journal of Zoology 44: 193–203.
• Seeman and Walter 1995Seeman and Walter 1995:
  Seeman OD, Walter DE. 1995. Life history of Afrocypholaelaps africana (Evans) (Parasitiformes: Ameroseiidae), a mite inhabiting mangrove flowers and phoretic on honeybees. Journal of the Australian Entomological Society 34: 45–50.