Ticks are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians. The timing of the origin of ticks is uncertain, though the oldest known tick fossils are from the Cretaceous period, around 100 million years old. Ticks are widely distributed around the world, especially in warm, humid climates.
The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of over 700 species. They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'soft ticks' (Argasidae), lack. They are ectoparasites of a wide range of host species, and some are vectors of pathogens that can cause human disease.
Nuttalliella namaqua is a tick found in southern Africa from Tanzania to Namibia and South Africa, which is placed in its own family, Nuttalliellidae. It can be distinguished from ixodid ticks and argasid ticks by a combination of characteristics including the position of the stigmata, lack of setae, strongly corrugated integument, and form of the fenestrated plates. It is the most basal lineage of ticks.
Amblyomma is a genus of hard ticks. Some are disease vectors, for example the Rocky Mountain spotted fever in United States or ehrlichiosis in Brazil.
Dermacentor is a genus of ticks in the family Ixodidae, the hard ticks. The genus has a cosmopolitan distribution, with native species on all continents except Australia. Most are found in North America.
Rhipicephalus is a genus of ticks in the family Ixodidae, the hard ticks, consisting of about 74 or 75 species. Most are native to tropical Africa.
Amblyomma cajennense or Cayenne tick is a species of tick found in a range from the southern part of the United States to northern Argentina, through Central America and some of the Caribbean. As a consequence, the species has adapted to a wide range of environmental conditions. There are also major geographic barriers such as large rivers and the Andes mountain range.
Haller's organ is a complex sensory organ possessed by hard and soft ticks. Not found outside of Acari, it is proposed to function like the chemosensation of insect antennae, but is structurally different. Ticks, being obligate parasites, must find a host in order to survive. Bloodmeals are necessary for completion of the life cycle, including reproduction and ontogenetic development. First described in 1881, it was named for its discoverer, Haller. While Haller initially proposed it was involved in auditory sensation, this was rejected in favor of olfactory sensation by 1905. This theory was supported by Lee's behavioral studies as early as 1948.
Ticks of domestic animals directly cause poor health and loss of production to their hosts. Ticks also transmit numerous kinds of viruses, bacteria, and protozoa between domestic animals. These microbes cause diseases which can be severely debilitating or fatal to domestic animals, and may also affect humans. Ticks are especially important to domestic animals in tropical and subtropical countries, where the warm climate enables many species to flourish. Also, the large populations of wild animals in warm countries provide a reservoir of ticks and infective microbes that spread to domestic animals. Farmers of livestock animals use many methods to control ticks, and related treatments are used to reduce infestation of companion animals.
Rhipicephalus hoogstraali is a tick found in Djibouti and Somalia. First recognized by Harry Hoogstraal as Rhipicephalus longicoxatus based on an incomplete published description, after discovery of the holotype of R. longicoxatus, it was described and named to honor Hoogstraal in 2009.
Amblyomma triguttatum, commonly known as the kangaroo tick, is a species of tick in the genus Amblyomma native to Australia, in Western Australia, parts of Queensland, and in New South Wales.
Amblyomma gervaisi is a hard-bodied tick of the genus Amblyomma. The tick is a parasite of snakes, such as Naja naja, Python molurus species and monitor species such as Varanus ocellatus, Varanus yemenensis, Varanus benghalensis, Varanus griseus and many other Varanus species in southeastern Asia and Asia-minor. They exhibit sexual dimorphism. They can be found in Sri Lanka, India, Yemen, Saudi Arabia. It is a potential vector for Coxiella burnetii.
Amblyomma javanense is a hard-bodied tick of the genus Amblyomma. It is found in Vietnam, Indonesia, Malaysia, India, Sri Lanka, Philippines and Thailand. It is the only ectoparasite found on the Manis javanica, Manis crassicaudata and also from Sus scrofa.
Dermacentor reticulatus, also known as the ornate cow tick, ornate dog tick, meadow tick, and marsh tick, is a species of tick from the family Ixodidae. It is the type species for the genus Dermacentor. D. reticulatus is an ornate tick. The female varies in size from 3.8–4.2 mm (unfed) to 10 mm when engorged after feeding. The unfed male is 4.2–4.8 mm long. D. reticulatus is found in Europe and Western Asia, generally in wooded areas.
The zebra tick or yellow back tick is a species of hard tick. It is common in the Horn of Africa, with a habitat of the Rift Valley and eastward. It feeds upon a wide variety of species, including livestock, wild mammals, and humans, and can be a vector for various pathogens. The adult male has a distinctive black and ivory ornamentation on its scutum.
Margaropus is a genus of ticks, characterized as inornate, having eyes, lacking festoons, and with the legs of the male increasing in size from pair I to IV with the segments enlarged, giving them a beaded appearance, from which the genus name was taken, margaritopus signifying beady-legged; the species name memorialized naturalist and entomologist Wilhelm von Winthem.
Archaeocroton sphenodonti, or the tuatara tick, is a species of tick that parasitises only the tuatara of New Zealand. It is found on just four of the twelve island groups where tuatara survive, preferring islands where the reptiles live in high densities. Larvae, nymphs, and adults all feed exclusively on tuatara blood, and ticks can survive for up to a year without a host. When tuatara are translocated, the tick has been lost or survives only in low densities in the new population. It is the only living species in the genus Archaeocroton.
Cosmiomma is a genus of ticks first discovered by Paul Schulze in 1919. It is monospecific, being represented by the single species Cosmiomma hippopotamensis. It was first described in 1843 by Henry Denny from specimens collected from a hippopotamus in Southern Africa, and has been called "one of the most unusual, beautiful, and rare tick species known to the world."
Maria Tonelli-Rondelli (1899–1970) was an Italian entomologist who studied the taxonomy and identification of ticks (Ixodidae), especially South American species.
