Astigmatina Temporal range: | |
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Otodectes cyanotis (Psoroptidia: Psoroptidae) | |
Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Sarcoptiformes |
(unranked): | Astigmatina Canestrini, 1891 |
Superfamilies | |
Diversity | |
c. 76 families > 1,000 genera > 3,400 species |
Astigmatina is a clade of mites in the superorder Acariformes. Astigmata has been ranked as an order or suborder in the past, but was lowered to the unranked clade Astigmatina of the clade Desmonomatides (synonym Desmonomata) in the order Sarcoptiformes. Astigmatina is now made up of the two groups Acaridia and Psoroptidia, which have been suborders of the order Astigmata in the past. Astigmatina contains about 10 superfamilies and 76 families under Acaridia and Psoroptidia. [1] [2]
Astigmatina belongs to the Sarcoptiformes, which contains the "biting" Acariformes. Many species are parasites of vertebrates. Most notorious among these are the Psoroptidia, which contain such notable taxa as feather mites and Sarcoptes scabiei .
Astigmatan mites are usually soft-bodied and white to brownish in colour (rarely tan and well-sclerotised), and range from 0.15 to 2.00 mm in length. They lack stigmatal openings (thus the name of the clade), peritremes or prodorsal sensilla. The gnathosoma (mouthparts) is usually exposed. They have a pair of chelicerae that are 2-segmented and usually chelate-dentate in shape (whip-like in Histiostomatidae). Opisthosomal glands are present and usually well-developed. [3]
Some features vary depending on the life stage. Larvae have six legs (hexapod) whereas nymphs and adults have eight legs (octopod). The genital opening has one pair of genital papillae in the protonymph (first nymphal stage), but two pairs in the tritonymph (last nymphal stage) and adult. [3]
Some astigmatans have a deutonymph stage which looks very different from other stages (heteromorphic). This is usually adapted for phoresy (attachment to a larger animal for transport), being well-sclerotised (to resist desiccation), with a reduced gnathosoma and a solid, non-functional foregut (as deutonymphs generally do not feed) and usually a posteroventral attachment organ. Some lineages have two possible types of heteromorphic deutonymph, with the other being sac-like and immobile (immobile heteromorphic deutonymph). The purpose of this deutonymph type is to survive environmental stresses for long periods of time. [4]
Males have an aedeagus in a usually postcoxal position. Females have a secondary sperm-receiving structure with a bursa copulatrix. [3]
Unlike their oribatid ancestors, which are mostly restricted to soil, [4] the Astigmatina show a wide range of ecological strategies. The Histiostomatoidea live in various wet substrates such as decaying plant tissue, dung, mud and tree holes, and feed on organic material. The Glycyphagoidea live in mammal nests, human houses and stored foods. The Pyroglyphoidea live in houses as house dust mites. Many Acaroidea live in stored foods, but the superfamily also includes plant pests and inhabitants of vertebrate or insect nests. The majority of Hemisarcoptoidea are kleptoparasites. The Canestrinoidea are parasites feeding on exudates of beetles. The also-parasitic Sarcoptoidea live in mammal fur and skin. Several superfamilies are exclusively associated with birds (Pterolichoidea, Freyanoidea and Analgoidea) or bird nests (Hypoderatoidea). [5]
Among the mites occurring in soil, Astigmatina is the least common group, though they may be common in some habitats. Their populations in agricultural soils increase after harvesting or the application of rich manures. Most soil-dwelling Astigmatina are microbe feeders, though the species with chelate chelicerae can chew on vegetable material, fungi and algae. [6]
Several astigmatan families are obligate associates of bees, which feed within bee nests. [7] The genus Chaetodactylus can form both phoretic deutonymphs (to disperse to new nests on adult bees) and immobile deutonymphs (to survive in old nests so they can infest bees that reuse nests). [8]
Astigmatina in homes damage stored products, disperse microbial propagules and contribute to allergic reactions. The parasitic species cause diseases such as scabies and mange. A few acarid species are minor pests of seedling crops. [3]
There are also beneficial species of Astigmatina. Hemisarcoptes (Hemisarcoptidae) are parasites of armoured scale insects, which are plant pests. [9]
Astigmatina contains about 11 superfamilies with thousands of genera, as follows: [10] [11]
Mites are small arachnids. Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evidence of a close relationship.
The Acariformes, also known as the Actinotrichida, are the most diverse of the two superorders of mites. Over 32,000 described species are found in 351 families, with an estimated total of 440,000 to 929,000 species, including undescribed species.
Mesostigmata is an order of mites belonging to the Parasitiformes. They are by far the largest group of Parasitiformes, with over 8,000 species in 130 families. Mesostigmata includes parasitic as well as free-living and predatory forms. They can be recognized by the single pair of spiracles positioned laterally on the body.
Oribatida, 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 0.2 to 1.4 millimetres. 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.
Psoroptidia is a parvorder of the Acari (mite) group Astigma. It comprises around 40 families, and apparently originated as parasites of birds, before a secondary radiation saw some taxa become parasites of mammals. Because of their parasitic lifestyle, members of the Psoroptidia do not exhibit a deutonymph stage.
Eriophyoidea are a superfamily of herbivorous mites. All post-embryonic instars lack the third and fourth pairs of legs, and the respiratory system is also absent.
The Prostigmata is a suborder of mites belonging to the order Trombidiformes, which contains the "sucking" members of the "true mites" (Acariformes).
The Raphignathoidea is a superfamily of the Acari (mite) order Trombidiformes, comprising 1087 species in 62 genera and 12 families.
Histiostomatidae is a family of mites in the clade Astigmata.
Parasitidae is a family of predatory mites in the order Mesostigmata that has worldwide distribution. They are the only family in the superfamily Parasitoidea. Relatively large for mites, their color is often yellowish to dark brown. The family as a whole preys on a wide variety of microarthropods and nematodes, with individual species usually having a narrower range of prey. The family contains two subfamilies, 29 genera, and around 400 species.
Parasitengona is a group of mites, variously ranked as a hyporder or a cohort, between the taxonomic ranks of order and family.
Histiostoma is a genus of mites in the family Histiostomatidae.
Dermanyssoidea is a superfamily of mites, including most of the mites which parasitise vertebrates.
The family Ameroseiidae is one of the three families of mites under the superfamily Ascoidea. There are about 12 genera and more than 130 described species in Ameroseiidae. The family has a worldwide distribution.
Phoresis or phoresy is a non-permanent, commensalistic interaction in which one organism attaches itself to another solely for the purpose of travel. Phoresis has been observed directly in ticks and mites since the 18th century, and indirectly in fossils 320 million years old. It is not restricted to arthropods or animals; plants with seeds that disperse by attaching themselves to animals are also considered to be phoretic.
Chaetodactylus is a genus of parasitic mite primarily associated with solitary bees with over 20 species.
Chaetodactylidae is a family of mites in the order Sarcoptiformes. There are five genera: Sennertia, Chaetodactylus, Achaetodactylus, Centriacarus, and Roubikia.
Winterschmidtiidae is a family of mites in the order Astigmata.
Roubikia is a genus of bee-associated mites occurring in the neotropics. They are mutualists or commensals, and feed on fatty acids from floral oils and most likely on fungi. The type species is Chaetodactylus panamensis.
Uropodina is an infraorder of mites in the order Mesostigmata.