Sarcoptiformes

Superorder Acariformes

  Order Sarcoptiformes

 Suborders: Endeostigmata, Oribatida

    

Common names: sarcoptiform mites, endeostigmatans, oribatids (including astigmatans)

 

Probability of Encounter: high

 

Quarantine importance: High, but almost entirely because of the Astigmatina, previously treated as the suborder Astigmata, but now recognized as a cohort in the Oribatida.  Most endeostigmatans and oribatids are of little interest to quarantine since they are primarily soil/litter inhabitants that feed on fungi, other microbes, decaying organic matter and small invertebrates (e.g. nematodes, tardigrades, rotifers).  Only a few sarcoptiform mites feed on living plant tissue and these are usually insignificant as pests.  The Astigmatina, however, includes important parasites of people, livestock, pets, wildlife and insects, as well as many fungivores and scavengers that are pests in stored products and homes.

 

Diagnosis.  Very small (0.15 mm long) to large (5 mm) mites without primary stigmatal openings or peritremes, sometimes with secondary respiratory systems (porose areas, brachytracheae); gnathosoma exposed or withdrawn into camerostome, cheliceral bases not covered by sclerotized ring; palps with 1-5 free segments, without palp apotele; subcapitulum without median groove, rutella (pseudorutella) setiform, stalked-dentate, to toothed, chisel-like or obscure (rarely lost); tritosternum absent; coxae fused to body, forming epimeral fields or reduced to internal sclerotized elements (apodemes); chelicerae 2-segmented; with or without prodorsal trichobothria; intercoxal region without sternal and genital shield elements; development: +/- hexapod prelarva, hexapod larva and 2-3 octopod nymphal stages (protonymph, +/- deutonymph, tritonymph); genital opening develops gradually with 1 pair of genital papillae added in the protonymph, a second pair usually added in the deutonymph, and a third pair often added in the tritonymph; males with a spermatophoric organ or (Astigmatina) an aedeagus, chelicerae not modified for sperm transfer; female sperm receiving structure primary or secondary (Astigmatina), with bursa copulatrix.

 

Similar mites.    Uropodid mites (Mesostigmata: Monogynaspides) superficially resemble brachypyline oribatid mites, but have tritosterna, intercoxal genital openings (except for Metagynella), lateral stigmata and peritremes.  Heterostigmatina (Prostigmata: Eleutherengonides) have a gnathosomal capsule.

 

Ecology & Distribution.  Sarcoptiformans are the dominant arthropods in soil/litter systems (including suspended soils, bogs, and cold and dry desserts).  Most species feed on fungi, other microbes, decaying organic matter and small invertebrates (e.g. nematodes, tardigrades, rotifers).  This is also true for most of those that inhabit vegetation and only a few species feed on health plant tissue.  Astigmatina are exceptional in that many species are pests of stored products or parasites of animals, and a few are predators of insects or graze on living plants.

 

References

Hughes AM.  1976.  The Mites of Stored Food and Houses.  Technical Bulletin 9, Ministry of Agriculture, Fisheries and Food: London

Krantz GW.  1976.  A Manual of Acarology.  OSU Bookstores: Corvallis.