Oribatida

Oribatida (formerly Cryptostigmata), also known as oribatid mites, moss mites or beetle mites, are an order of mites, in the "chewing Acariformes" clade Sarcoptiformes. They range in size from . There are currently 12,000 species that have been identified, but researchers estimate that there may be anywhere from 60,000 to 120,000 total species. Oribatid mites are by far the most prevalent of all arthropods in forest soils, and are essential for breaking down organic detritus and distributing fungi.
Oribatid mites generally have low metabolic rates, slow development and low fecundity. Species are iteroparous with adults living a relatively long time; for example, estimates of development time from egg to adult vary from several months to two years in temperate forest soils. Oribatid mites have six active instars: prelarva, larva, three nymphal instars and the adult. All these stages after the prelarva feed on a wide variety of material including living and dead plant and fungal material, lichens and carrion; some are predatory, but none is parasitic and feeding habits may differ between immatures and adults of the same species.
Many species have a mineralized exoskeleton as adults. In some, this includes a pair of pteromorphae: wing-like flaps that overhang the legs on either side. Some oribatids can also tuck in their legs underneath their protective armor, an ability known as ptychoidy, for more defence against predation.
Alkaloids are produced by some oribatids, presumably as another defence against predation. In turn, poison dart frogs that prey on oribatids sequester these alkaloids for their own defence.
The Oribatida are of economic importance as hosts of various tapeworm species, and by increasing the breakdown of organic material in the soil, in a similar manner to earthworms.
Many species of oribatid mites require extremely specific habitats, resulting in large diversity within the order due to the many niches they evolve to. Some species are especially suited to dry conditions, or on bare lichen covered rocks, but that largest section of Oribatida prefers the moist forest floor and its accompanying litter. There are a small number of species who have evolved to live on aquatic plants, often spending the majority of their life submersed underwater.
In contrast to the commonly held view that parthenogenetic lineages are short lived, four species-rich parthenogenetic clusters of the order Oribatida are very ancient and likely arose 400-300 million years ago. Parthenogenetic oribatid mite lineages have been hypothesized to be adapted to occupy narrow specialized ecological niches. However, it was recently shown that parthenogenetic oribatid mite species actually possess a widely adapted general-purpose genotype, and thus each such lineage might be viewed as a “jack-of-all-trades”.
The Astigmatina, though once considered a separate group, are now considered part of Oribatida. They are quite different from other oribatids (e.g. many astigmatans are soft-bodied and some are parasitic), resulting in them often being treated separately.
Systematics
The order Oribatida is divided into the following taxa:
Palaeosomata Grandjean, 1969
Acaronychoidea Grandjean, 1932 (6 genera)
Acaronychidae Grandjean, 1932
Palaeacaroidea Grandjean, 1932 (8 genera)
Palaeacaridae Grandjean, 1932
Parhyposomata Balogh & Mahunka, 1979
Parhypochthonioidea Grandjean, 1969 (3 genera)
Parhypochthoniidae Grandjean, 1969
Gehypochthoniidae Strenzke, 1963
Elliptochthoniidae Norton, 1975
Enarthronota Grandjean, 1947
Hypochthonoidea Berlese, 1910 (c. 8 genera)
Hypochthoniidae Berlese, 1910
Eniochthoniidae Grandjean, 1947
Arborichthoniidae Balogh & Balogh, 1992
Brachychthonoidea Thor, 1934 (c. 11 genera)
Brachychthoniidae Thor, 1934
Cosmochthonioidea Grandjean, 1947 (c. 14 genera)
Cosmochthoniidae Grandjean, 1947
Heterochthoniidae Grandjean, 1954
Haplochthoniidae Hammen, 1959
Pediculochelidae Lavoipierre, 1946
Sphaerochthoniidae Grandjean, 1947
Atopochthonioidea Grandjean, 1949 (3 genera)
Atopochthoniidae Grandjean, 1949
Pterochthoniidae Grandjean, 1950
Phyllochthoniidae Travé, 1967
Protoplophoroidea Ewing, 1917 (c. 7 genera)
Protoplophoridae Ewing, 1917
Mixonomata Grandjean, 1969
Dichosomata Balogh & Mahunka, 1979
Nehypochthonioidea Norton & Metz, 1980
Nehypochthoniidae Norton & Metz, 1980
Perlohmannioidea Grandjean, 1954
Perlohmaniidae Grandjean, 1954
Collohmanniidae Grandjean, 1958
Eulohmannioidea Grandjean, 1931
Eulohmanniidae Grandjean, 1931
Epilohmannioidea Oudemans, 1923
Epilohmanniidae Oudemans, 1923
Lohmannioidea Berlese, 1916
Lohmanniidae Berlese, 1916
Euptyctima Grandjean, 1967
Mesoplophoroidea Ewing, 1917
Mesoplophoridae Ewing, 1917
Euphthiracaroidea Jacot, 1930
Oribotritiidae Grandjean, 1954
Euphthiracaridae Jacot, 1930
Synichotritiidae Walker, 1965
Phthiracaroidea Perty, 1841
Phthiracaridae Perty, 1841
Steganacaridae Niedbała, 1986
Holosomata Grandjean, 1969
Crotonioidea Thorell, 1876
Thrypochthoniidae Willmann, 1931
Malaconothridae Berlese, 1916
Nothridae Berlese, 1896
Camisiidae Oudemans, 1900
Crotoniidae Thorell, 1876
Nanhermannioidea Sellnick, 1928
Nanhermanniidae Sellnick, 1928
Hermannioidea Sellnick, 1928
Hermanniidae Sellnick, 1928
Brachypylina Hull, 1918
Pycnonoticae Grandjean, 1954
Hermannielloidea Grandjean, 1934 (2 families)
Neoliodoidea Sellnick, 1928 (1 family)
Plateremaeoidea Trägårdh, 1926 (4 families)
Gymnodamaeoidea Grandjean, 1954 (2 families)
Damaeoidea Berlese, 1896 (1 family)
Polypterozetoidea Grandjean, 1959 (2 families)
Cepheoidea Berlese, 1896 (7 families)
Charassobatoidea Grandjean, 1958 (3 families)
Microzetoidea Grandjean, 1936 (1 family)
Zetorchestoidea Michael, 1898 (1 family)
Gustavioidea Oudemans, 1900 (8 families)
Eremaeoidea Oudemans, 1900 (4 families)
Amerobelboidea Grandjean, 1954 (10 families)
Eremelloidea Balogh, 1961 (7 families)
Oppioidea Sellnick, 1937 (12 families)
Trizetoidea Ewing, 1917 (6 families)
Otocepheoidea Balogh, 1961 (4 families)
Carabodoidea Koch, 1837 (3 families)
Tectocepheoidea Grandjean, 1954 (2 families)
Hydrozetoidea Grandjean, 1954 (1 family)
Ameronothroidea Willmann, 1931 (3 families)
Cymbaeremaeoidea Sellnick, 1928 (3 families)
Poronoticae Grandjean, 1954
Licneremaeoidea Grandjean, 1931 (6 families)
Phenopelopoidea Petrunkevitch, 1955 (1 family)
Unduloribatoidea Kunst, 1971 (3 families)
Limnozetoidea Thor, 1937 (2 families)
Achipterioidea Thor, 1929 (2 families)
Oribatelloidea Jacot, 1925 (3 families)
Ceratozetoidea Jacot, 1925 (5 families)
Zetomotrichoidea Grandjean, 1934 (1 family)
Oripodoidea Jacot, 1925 (19 families)
Galumnoidea Jacot, 1925 (3 families)
See also
Archegozetes longisetosus
Conoppia palmicinctum
Neotrichozetes
References
Further reading
Acariformes
Arachnid orders