Monogynaspida

Superorder Parasitiformes

Order Mesostigmata

Suborder Monogynaspida

Cohorts (superfamilies): Microgyniina (Microgynioidea); Heatherellina (Heatherelloidea); Uropodina (Thinozerconoidea, Polyaspidoidea, Uropodoidea, Trachyuropodoidea); Heterozerconina (Heterozerconoidea); Gamasina (Epicrioidea, Zerconoidea, Arctacaroidea, Parasitoidea, Vegaioidea, Rhodacaroidea, Eviphidoidea, Ascoidea, Phytoseioidea, Dermanyssoidea)

 

Common names: gamasines, uropodines (turtle mites, tortoise mites), parasitines, ascids, phytoseiids, predatory mites

 

Probability of Encounter: high

 

Quarantine importance: Most of the Mesostigmata encountered in quarantine intercepts are likely to be members of the Monogynapsida, including many species parasitic on birds (e.g. poultry mites), mammals (e.g. rat mites), reptiles (e.g. the snake mite), and bees (e.g. varroa, Tropilaelaps); predatory mites used in biocontrol; flower mites; stored product predators; and predatory soil mites.  Some of the vertebrate parasites (Dermanyssoidea) vector disease.

 

Diagnosis.  Mesostigmata with the adult female having a single genital shield covering the ovipore and bearing 0-1 (rarely 2) pairs of genital setae; genital shield truncate or rounded posteriorly, sometimes extending over venter and incorporating ventral setae; other ventral shields highly variable.  Tarsus IV without intercalary sclerite bearing setae av4/pv4.  Capitulum exposed or hidden under vertex.

 

Body chaetome variable, sometimes hypertrichous but usually with 65 or fewer pairs of setae; dorsal shielding entire (holodorsal) or fragmented with variously formed podonotal, mesonotal and pygidial shields or divided into two subequal shields (podonotal, opisthonotal).   Unpaired, postanal seta usually present in all stages.  Chelicerae various; movable digit without excrescences except in Microgyniina, but arthrodial corona or brush may be present; palp genu with 6 or fewer setae.  Corniculi horn-like, bifurcate, or rarely truncate; hypostomal groove usually broad and with 1-many denticles; epistome various.  Males with genital opening mid-coxal or at base of tritosternum; movable digit with or without spermatodactyl or spermatotreme; legs II and IV often with tubercles.

 

Similar mites.  Trigynaspida usually have 2-4 distinct genital shields, cheliceral excrescences, and an intercalary sclerite bearing setae av4/ pv4; Sejina have av4 / pv4 and a single large genital shield that usually bears 3 or more pairs of setae.

 

Ecology & Distribution.  Monogynaspides accounts for most of the 12,000 or so described species of Mesostigmata and are found on every continent, including two species known from Antarctica.  Most species are either free-living predators or parasites of vertebrates and invertebrates, but others are fungivores, scavengers, or feed on pollen or nectar.

 

References

Evans EO and Till WM.  1979.  Mesostigmatic mites of Britain and Ireland (Chelicerata: Acari-Parasitiformes).  An introduction to their external morphology and classification.  Transactions of the Zoological Society of London 35 (2): 145-270.

Gilyarov MS & Bregatova NG (eds)  1977.  Handbook for the Identification of Soil-inhabiting Mites, Mesostigmata.  Zoological Institute of the Academy of Sciences: Petrograd [In Russian]

Johnston, D.E.  1982.  Mesostigmata.  In: Parker, S.P. (ed.)  Synopsis and classification of living organisms.  McGraw-Hill, New York, p. 112-116.

Karg, W.  1993.  Teil 59.  Acari (Acarina), Milben Parasitiformes (Anactinotrichaeta) Cohors Gamasina Leach.  Raubmilben.  Gustav Fischer Verlag: New York.  523 pp. [In German]

Krantz GW.  1978.  A Manual of Acarology.  OSU Bookstores: Corvallis.

Krantz, GW & Ainscough, B.  1990.  Mesostigmata.  pp. 583-665, in DL Dindal (ed) Soil Biology Guide.  John Wiley & Sons: Brisbane.

Walter DE and Proctor HC.  1999.  Mites: Ecology, Evolution and Behaviour. University of NSW Press, Sydney and CABI, Wallingford.