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.
Ixodes holocyclus, commonly known as the Australian paralysis tick, is one of about 75 species in the Australian tick fauna and is considered the most medically important. It can cause paralysis by injecting neurotoxins into its host. It is usually found in a 20-kilometre wide band following the eastern coastline of Australia. Within that range, Ixodes holocyclus is the tick most frequently encountered by humans and their pets. Because the same area includes Australia's most densely populated regions, bites on people, pets and livestock are relatively common.
Dermacentor variabilis, also known as the American dog tick or wood tick, is a species of tick that is known to carry bacteria responsible for several diseases in humans, including Rocky Mountain spotted fever and tularemia. It is one of the best-known hard ticks. Diseases are spread when it sucks blood from the host. It may take several days for the host to experience symptoms.
Ixodiphagus hookeri, the tick wasp, is an encyrtid wasp which lays its eggs into ticks. It seems to use a symbiotic bacteria, Wolbachia pipientis, to weaken the tick's immune system.
Ixodes scapularis is commonly known as the deer tick or black-legged tick, and in some parts of the US as the bear tick. It was also named Ixodes dammini until it was shown to be the same species in 1993. It is a hard-bodied tick found in the eastern and northern Midwest of the United States as well as in southeastern Canada. It is a vector for several diseases of animals, including humans and is known as the deer tick owing to its habit of parasitizing the white-tailed deer. It is also known to parasitize mice, lizards, migratory birds, etc. especially while the tick is in the larval or nymphal stage.
Ixodes ricinus, the castor bean tick, is a chiefly European species of hard-bodied tick. It may reach a length of 11 mm (0.43 in) when engorged with a blood meal, and can transmit both bacterial and viral pathogens such as the causative agents of Lyme disease and tick-borne encephalitis.
Amblyomma americanum, also known as the lone star tick, the northeastern water tick, or the turkey tick, is a type of tick indigenous to much of the eastern United States and Mexico, that bites painlessly and commonly goes unnoticed, remaining attached to its host for as long as seven days until it is fully engorged with blood. It is a member of the phylum Arthropoda, class Arachnida. The adult lone star tick is sexually dimorphic, named for a silvery-white, star-shaped spot or "lone star" present near the center of the posterior portion of the adult female shield (scutum); adult males conversely have varied white streaks or spots around the margins of their shields.
Rhipicephalus sanguineus, commonly called the brown dog tick, kennel tick, or pantropical dog tick, is a species of tick found worldwide, but more commonly in warmer climates. This species is unusual among ticks in that its entire lifecycle can be completed indoors. The brown dog tick is easily recognized by its reddish-brown color, elongated body shape, and hexagonal basis capituli. Adults are 2.28 to 3.18 mm in length and 1.11 to 1.68 mm in width. They do not have ornamentation on their backs.
Dermacentor andersoni, commonly known as the Rocky Mountain wood tick, is a hard tick, or member of the Ixodidae family, with three life stages including larvae, nymph, and finally adult, or, more entomologically, imago. This tick is generally located in the northwest United States and southwest Canada along the Rocky Mountains. This tick is generally a vector for Colorado tick fever, but can also be a vector for Rocky Mountain spotted fever and tularemia. During the larval and nymphal stages, the tick does not feed on humans, but during the adult stage, it will. Prevention of infections associated with these ticks is based on control of exposure to the vector, including wearing proper clothing when in woods/wet areas, and checking oneself thoroughly after returning home. Adult female ticks can feed for 5 to 15 days, thus removing a tick if present is very important. Follow general tick removal tips.
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.
The Asian blue tick is an economically important tick that parasitises a variety of livestock and wild mammal species, especially cattle, on which it is the most economically significant ectoparasite in the world. It is known as the Australian cattle tick, southern cattle tick, Cuban tick, Madagascar blue tick, and Puerto Rican Texas fever tick.
Ornithodoros hermsi is a species of soft tick. It can be infected with Borrelia hermsii.
Ixodes hexagonus, also known by the common name hedgehog tick, is a tick species in the genus Ixodes. It is a parasite of the European hedgehog.
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.
Lyme disease is spread to humans through the bite of infected ticks. The tick population is affected by weather and climate. Many factors determine tick population densities as well as diseased population densities of ticks so that no single factor can determine likelihood of exposure to tick-borne disease. Overall climate and primary host population determine the localities where ticks will thrive. However, studies have been conducted which correlate tick population to climate change and their behavior to weather patterns. Ticks are parasites which carry a myriad of infectious diseases that depend on the species of tick. Overall climate is more determinate of tick population and daily weather has a subtle effect on the spread of tick-borne disease. Being mindful of daily weather patterns and vigilantly avoiding exposure to ticks reduces human exposure to Lyme disease.
Haemaphysalis leporispalustris, the rabbit tick, is a species of tick that is widely distributed in the Americas, stretching from Alaska to Argentina. H. leporispalustris is known to have one of the largest distributions for a tick originating in the New World. It is a three-host tick and a member of the family Ixodidae, commonly called the "hard ticks," and the genus Haemaphysalis. Its common hosts are rabbits, hares, and sometimes ground-feeding birds. H. leporispalustris has a rigid scutum and a prominent capitulum projecting forward from its body and is often said to look like the "wood tick". It has a hemimetabolic life cycle. H. leporispalustris does not play a prominent role in disease transmission in humans but is a vector for disease in other animals.
Rhipicephalus annulatus, the cattle tick, is a hard-bodied tick of the genus Rhipicephalus. It is also known as North American cattle tick, North American Texas fever tick, and Texas fever tick.
Ixodes angustus is a species of parasitic tick, whose range encompasses the majority of Canada and the United States, along with parts of northern Mexico. I. angustus is a member of the Ixodidae (hard-bodied) family of ticks. It is most abundant in cool, moist biomes such as riparian, boreal or montane zones. I. angustus is a host generalist and has been discovered feeding on more than 90 different host species, including humans and domestic dogs. I. angustus has been identified as a potential vector for Lyme disease but is not considered a principal vector due to the relative rarity with which it feeds on humans.
