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. However, most recent genetic analyses do not recover the two as each other's closest relative within Arachnida, rendering the group non-monophyletic. Most mites are tiny, less than 1 mm (0.04 in) in length, and have a simple, unsegmented body plan. The small size of most species makes them easily overlooked; some species live in water, many live in soil as decomposers, others live on plants, sometimes creating galls, while others again are predators or parasites. This last type includes the commercially destructive Varroa parasite of honey bees, as well as scabies mites of humans. Most species are harmless to humans, but a few are associated with allergies or may transmit diseases.
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.
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 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.
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.
The Proctophyllodidae are a family of the Acarina (mite) order Astigmata. They contain many feather mites. The Alloptidae and Trouessartiidae were in earlier times included here as subfamilies.
Endeostigmata is a suborder of acariform mites. There are about ten families in Endeostigmata. The grouping is strongly suspected to be paraphyletic, containing unrelated early diverging lineages of mites.
Plateremaeidae is a family of oribatids in the order Sarcoptiformes. There are about 7 genera and 19 described species in Plateremaeidae.
Torrenticolidae is a family of torrent mites in the order Trombidiformes. There are about 5 genera and at least 20 described species in Torrenticolidae.
Echimyopodidae is a family of mites in the order Astigmata. There are at least two genera and two described species in Echimyopodidae.
Avenzoariidae is a family of feather mites in the order Astigmata. There are at least 15 genera in Avenzoariidae. They are found on the feathers of aquatic birds, and in the case of one species, birds of prey.
Winterschmidtiidae is a family of mites in the order Astigmata.
Mochlozetidae is a family of mites and ticks in the order Sarcoptiformes. There are about 12 genera and at least 50 described species in Mochlozetidae.
Phenopelopidae is a family of oribatid mites in the order Sarcoptiformes. As of 2018, there were 4 genera and 106 species known in this family.
Bdellidae is a family of snout mites in the order Trombidiformes. There are about 11 genera and at least 260 described species in Bdellidae.
Stigmaeidae is a family of prostigmatan mites in the order Trombidiformes. At over 600 species, it is the largest family in superfamily Raphignathoidea. It has a worldwide distribution.
Pterygosomatidae is a family of prostigs in the order Trombidiformes. There are at least two genera and two described species in Pterygosomatidae.
Mideopsidae is a family of prostigs in the order Trombidiformes. There are about 7 genera and 19 described species in Mideopsidae.
Glycyphagus is a genus of astigs in the family Glycyphagidae.
Glyphanoetus is a genus of astigs in the family Histiostomatidae.
Chaetodactylus krombeini,, was described by Karl Krombein and E. W. Baker in the 1960s. The mites are about 0.5 mm across, with the females larger than the males. Pollen mites are a kleptoparasitic pest of Megachilid solitary bees, with Ch. krombeini found with Osmia lignaria of North America,. Pollen mites do not feed on bees, but rather their provisions, and are harmful because they consume the food resources and starve or stunt the developing larvae; there is evidence that pollen mites also directly harm the egg by puncturing it.
Chaetodactylus krombeini female lateral propodosoma showing enlarged supracoxal sclerite. This trait is diagnostic for the family Chaetodactylidae.
