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.
The Acariformes, also known as the Actinotrichida, are the more 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.
Erythraeidae is a family of mites belonging to the Trombidiformes. Larval forms of these mites are parasitic on various other arthropods, for example harvestmen, but the adults are free-living predators. These oval mites are rather large, usually reddish coloured and densely hairy. The legs, especially the first and fourth pairs, are long and adapted for running. They have either one or two pairs of eyes and can be distinguished from related families microscopically by the presence of a single claw on the tibia of the palp.
Smarididae is a family of mites belonging to the order Trombidiformes. These large predatory mites have long oval bodies, distinctively pointed in front. They are usually red and densely hairy with slender legs, sometimes very long. They have either one or two pairs of eyes.
Erythraeus is a genus of mites belonging to the family Erythraeidae. These are large red mites with two pairs of eyes and long legs.
Erythraeus munsteri is a species of mite belonging to the family Erythraeidae. This is a large, oval red mite with a body length of up to 1.5 mm. It has two pairs of eyes and long, slender legs. This mite can easily be distinguished from closely related species by the extraordinarily long, blackish setae which cover the body and legs.
Balaustium is a genus of mites belonging to the family Erythraeidae. These are large red mites with one or two pairs of eyes set well back on the body.
Balaustium vignae is a species of mite belonging to the family Erythraeidae. This moderately hairy orange mite is around 1 mm in length with one pair of eyes set well back on the body. It can be distinguished from similar species by the first pair of legs being longer than the body and the lack of a suture dividing the abdomen.
Balaustium medicagoense is a species of mite belonging to the family Erythraeidae. This large, densely hairy mite is up to 1.6 mm in length with one pair of eyes set well back on the body. The first pair of legs is just longer than the body.
Balaustium bipilum is a species of mite belonging to the family Erythraeidae. This long-oval shaped, sparsely hairy orange mite is less than 1 mm in length with one pair of eyes set well back on the body. It can be distinguished from similar species by the crista projecting forward beyond the margin of the body and the clear suture dividing the upper abdomen. This species is endemic to South Africa.
Balaustium cristatum is a species of mite belonging to the family Erythraeidae. This oval mite is only known from immature specimens: the eight-legged nymph is around 0.75 mm in length and moderately hairy with two pairs of eyes and all legs shorter than the body. The six-legged larva is only around 0.5 mm in length and sparsely hairy with one pair of eyes and the third pair of legs longer than the body.
Leptus is a genus of large mites belonging to the family Erythraeidae; they resemble members of the related genus Balaustium, but can be distinguished by the eyes, which in Leptus species are set much further forward on the body than in Balaustium species.
Leptus intermedius is a species of mite belonging to the family Erythraeidae. This is a large, oval mite with a total length of 1.7 mm. The body is densely hairy and there is one pair of eyes. The fourth pair of legs is longer than the body. This species has been recorded only in the Bathurst area of South Africa.
Fessonia is a genus of mites belonging to the family Smaridiidae. These mites can be distinguished from other related genera by having 2 pairs of eyes and always lacking sclerotized plates on the body.
Tydeus eriophyes is a species of mite belonging to the family Tydeidae. This small oval, eyeless mite is around 300 μm in length with a soft body covered in striations. It can be distinguished from similar species by the bluntly pointed, rod-like dorsal setae. This species is associated with the gall mite Eriophyes vitis on grapevines in the vicinity of Grabouw, South Africa.
Trombiculidae ; commonly referred to in North America as chiggers and in Britain as harvest mites, but also known as berry bugs, bush-mites, red bugs or scrub-itch mites, are a family of mites. Chiggers are often confused with jiggers – a type of flea. Several species of Trombiculidae in their larva stage bite their animal or human host and by embedding their mouthparts into the skin cause "intense irritation" or "a wheal, usually with severe itching and dermatitis".
Parasitengona is a group of mites, variously ranked as a hyporder or a cohort, between the taxonomic ranks of order and family.
Hydrachnidia, also known as "water mites", Hydrachnidiae, Hydracarina or Hydrachnellae, are among the most abundant and diverse groups of benthic arthropods, composed of 6,000 described species from 57 families. As water mites of Africa, Asia, and South America have not been well-studied, the numbers are likely to be far greater. Other taxa of parasitengone mites include species with semi-aquatic habits, but only the Hydracarina are properly subaquatic. Water mites follow the general Parasitengona life cycle: active larva, inactive (calyptostasic) protonymph, active deutonymph, inactive tritonymph and active adult. Usually, larvae are parasites, while deutonymphs and adults are predators.
Eriophyes vitis, also known as grape erineum mite or blister mite, is a mite species in the genus Eriophyes infecting grape leaves. E. vitis has spread worldwide and has three distinct strains: a leaf-curling strain, a blister-causing strain, and a strain that stunts the growth of buds. It is a vector of grapevine pinot gris virus and grapevine inner necrosis virus.
Magdalena Kathrina Petronella Smith Meyer was a South African acarologist who was regarded as a world authority on plant-feeding mites of agricultural importance and was known as the "mother of red-spider mites of the world". She described more than 700 new species and 25 new genera, mostly of mites of agricultural importance. Meyer was involved in the promotion of biological control of mites using predatory mites, spiders and insects.
