What species of ticks exist? - briefly
Ticks are divided into hard (Ixodidae) and soft (Argasidae) families; hard species include Ixodes scapularis, Dermacentor variabilis and Amblyomma americanum, while soft species include Argas persicus and Ornithodoros moubata.
What species of ticks exist? - in detail
Ticks belong to the subclass Acari and comprise more than 900 described species. Taxonomically they are grouped into three families: Ixodidae (hard ticks), Argasidae (soft ticks), and the monotypic Nuttalliellidae.
The hard‑tick family Ixodidae contains the greatest diversity. Representative genera and species include:
- Ixodes – Ixodes scapularis (black‑legged tick) inhabits eastern North America, feeds on mammals and birds, and transmits Borrelia burgdorferi. Ixodes ricinus (castor bean tick) is widespread in Europe, parasitises a broad host range, and vectors tick‑borne encephalitis virus. Ixodes pacificus occurs on the western coast of the United States, sharing similar ecological traits.
- Dermacentor – Dermacentor variabilis (American dog tick) is common in the United States, prefers dogs and rodents, and can transmit Rocky Mountain spotted fever. Dermacentor andersoni (Rocky Mountain wood tick) occupies high‑altitude regions of western North America, also a vector of the same rickettsial disease.
- Amblyomma – Amblyomma americanum (lone star tick) expands across the southeastern United States, feeds on a wide range of vertebrates, and carries Ehrlichia chaffeensis. Amblyomma variegatum (tropical bont tick) occurs in sub‑Saharan Africa and the Caribbean, transmitting heartwater disease in livestock.
- Rhipicephalus – Rhipicephalus sanguineus (brown dog tick) thrives in domestic environments worldwide, feeds primarily on dogs, and spreads Babesia vogeli. Rhipicephalus microplus (cattle tick) dominates tropical regions, infests cattle, and transmits Anaplasma marginale.
The soft‑tick family Argasidae lacks a scutum and feeds rapidly. Notable species include:
- Ornithodoros hermsi, found in North American coniferous forests, feeds on small mammals and transmits relapsing fever Borrelia.
- Ornithodoros moubata, distributed across sub‑Saharan Africa, parasitises rodents and humans, and is a vector of African swine fever virus.
- Carios capensis, associated with seabird colonies, serves as a reservoir for various viral agents.
Nuttalliellidae is represented by a single species, Nuttalliella namaqua, recorded in southern Africa and the Arabian Peninsula. Its morphology combines features of hard and soft ticks, and its ecological role remains poorly understood.
Geographic distribution, host specificity, and vector competence vary markedly among these taxa, reflecting evolutionary adaptation to diverse habitats. Comprehensive identification relies on morphological keys, molecular sequencing, and ecological surveys.