The Acari are a taxon of arachnids that contains mites and ticks. The diversity of the Acari is extraordinary and their fossil history goes back to at least the early Devonian period. Acarologists have proposed a complex set of taxonomic ranks to classify mites. In most modern treatments, the Acari are considered a subclass of the Arachnida and are composed of two or three superorders or orders: Acariformes, Parasitiformes, and Opilioacariformes; the latter is often considered a subgroup within the Parasitiformes. The monophyly of the Acari is open to debate, and the relationships of the acarines to other arachnids is not at all clear. In older treatments, the subgroups of the Acarina were placed at order rank, but as their own subdivisions have become better understood, treating them at the superorder rank is more usual.
Eriophyidae is a family of more than 200 genera of mites, which live as plant parasites, commonly causing galls or other damage to the plant tissues and hence known as gall mites. About 3,600 species have been described, but this is probably less than 10% of the actual number existing in this poorly researched family. They are microscopic mites and are yellow to pinkish white to purplish in color. The mites are worm like, and have only two pairs of legs. Their primary method of population spread is by wind. They affect a wide range of plants, and several are major pest species causing substantial economic damage to crops. Some species, however, are used as biological agents to control weeds and invasive plant species.
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, and an estimated total of 440,000 to 929,000 species occur, including undescribed species.
Abacarus hystrix, the cereal rust mite or grain rust mite, belongs to the family Eriophyidae. They are extremely small with adults measuring up to 1 millimetre in length and only have four legs at the front of the body. Viewing by the human eye requires a 10 – 20X lens. The adult mites are usually yellow but also have been seen to be white or orange. The cereal rust mite was first found on Elymus repens, a very common perennial grass species. It has now been found on more than 60 grass species including oats, barley, wheat and ryegrass, found in Europe, North America, South Africa and Australia. Mites migrate primarily through wind movement and are usually found on the highest basal sections of the top two leaf blades. Abacarus hystrix produces up to twenty overlapping generations per year in South Australian perennial pastures, indicating that the species breeds quite rapidly. It has been noted that the cereal rust mite can cause losses in yield of up to 30-70%.
Aberoptus is a genus of mites belonging to the family Eriophyidae. These tiny mites, flattened in shape, live beneath the waxy layer on the underside of the leaves of certain plants.
The Prostigmata is a suborder of mites belonging to the order Trombidiformes, which contains the "sucking" members of the "true mites" (Acariformes).
Aceria is a genus of mites belonging to the family Eriophyidae, the gall mites. These tiny animals are parasites of plants. Several species can cause blistering and galls, including erineum galls. A few are economically significant pests, while others are useful as agents of biological pest control of invasive plants such as rush skeletonweed, creeping thistle, and field bindweed.
Aceria sheldoni, commonly called the citrus bud mite, is a species of mite belonging to the family Eriophyidae. It feeds in leaf- and flower-buds of Citrus spp., causing deformation to leaves, flowers and fruit, and is a worldwide pest of citrus fruit production.
The eriophyid coconut mite, Aceria guerreronis, is a mite which infests coconut plantations. It is economically devastating, and can destroy up to 60% of coconut production. The immature nuts are infested and injured by mites feeding in the portion covered by the perianth of the immature nut.
Floracarus perrepae is a species of herbivorous mite belonging to the family Eriophyidae. It is native to Australia (Queensland), China and New Caledonia. As it is known to attack and eat the invasive fern species Lygodium microphyllum, it is being considered for use as a biological pest control agent in Florida.
The Trombidiformes are a large, diverse order of mites.
Abacarus is a genus of acari, including the following species:
Aceria anthocoptes, also known as the russet mite, rust mite, thistle mite or the Canada thistle mite, is a species of mite that belongs to the family Eriophyidae. It was first described by Alfred Nalepa in 1892.
Aceria clianthi is a species of mite belonging to the family Eriophyidae. It is found only in New Zealand. It is notable for being host specific to threatened plants of the genus Clianthus. It is classified by Buckley et al. as "nationally critical" under the New Zealand Threat Classification System. They stated "Aceria clianthi (Eriophyidae), has been recorded only from kakabeak in cultivation and once on Lotus cornalatus [Lotus corniculatus] (Fabaceae), an introduced plant growing near kakabeak. It is given the same threat classification as kakabeak ." Heenan had earlier stated that "the two species [of Clianthus] are considered to be threatened, with C. maximus having a rank of vulnerable, whereas C. puniceus is critically endangered", but the conservation status of C. maximus was subsequently found to be more serious. These threat classifications for Clianthus apply to plants in the wild, but the species are widely cultivated. Aceria clianthi occurs on both plants in the wild and in cultivation.
Schinopsis brasiliensis is a species of flowering plant in the cashew family known by the common names baraúna or braúna.
Cecidophyes is a mite genus in the family Eriophyidae. It is a plant parasite, causing galls or other damage to the plant tissues.
Alfred Nalepa was an Austrian zoologist specializing in the field of acarology.
Aculops fuchsiae, commonly known as fuchsia gall mite, is a species of mite in the family Eriophyidae. It feeds on Fuchsia plants, causing distortion of growing shoots and flowers. It is regarded as a horticultural pest.
Aculops is a genus of mites that belongs to the family Eriophyidae that live as plant parasites. Some species, such as Aculops lycopersici, are severe crop or ornamental pests, while Aculops ailanthii is being considered as biocontrol for the extremely invasive tree-of-heaven in North America. Very little is known about this genus, with new species constantly being discovered even in well covered regions such as New Zealand.
Eriophyes cerasicrumena is a species of gall mite in the family Eriophyidae. This species was formerly a member of the genus Phytoptus. They produce galls on black cherry plants.
