A tick is not an insect, but what is it? - briefly
Ticks belong to the arachnid class, specifically the Acari subclass, making them relatives of spiders and mites rather than insects.
A tick is not an insect, but what is it? - in detail
Ticks belong to the subclass Acari, class Arachnida, and are therefore more closely related to spiders, scorpions, and mites than to insects. Their bodies consist of two main regions: the capitulum, which houses the mouthparts, and the idiosoma, containing the legs, digestive and reproductive organs. Adult ticks have eight legs, a distinguishing feature of arachnids, while the larval stage possesses six legs.
Physiologically, ticks are obligate hematophages; they feed exclusively on the blood of vertebrate hosts. Their feeding apparatus includes chelicerae for cutting tissue and a hypostome equipped with barbs that anchor the tick to the host’s skin. Saliva injected during attachment contains anticoagulants, anti‑inflammatory compounds, and immunomodulators that facilitate prolonged blood intake.
The life cycle comprises four stages: egg, larva, nymph, and adult. After hatching, each stage, except the egg, requires a blood meal to progress. Some species complete the cycle on a single host, while others alternate among multiple hosts, increasing the potential for pathogen transmission.
Ticks serve as vectors for a range of pathogens, including bacteria (e.g., Borrelia burgdorferi), viruses (e.g., tick‑borne encephalitis virus), and protozoa (e.g., Babesia spp.). Transmission occurs when infected salivary secretions enter the host during feeding. The epidemiological significance varies among tick families:
- Ixodidae (hard ticks) – possess a scutum, feed for days to weeks, major carriers of Lyme disease and Rocky Mountain spotted fever.
- Argasidae (soft ticks) – lack a scutum, feed quickly, associated with relapsing fever and African swine fever.
- Nuttalliellidae – a monotypic family with limited data, representing an evolutionary bridge between hard and soft ticks.
Control measures focus on habitat management, host treatment, and personal protection. Strategies include regular grooming of domestic animals, application of acaricides to livestock, and use of repellents or protective clothing for humans in endemic areas. Early detection and prompt removal of attached ticks reduce the risk of pathogen transmission; removal should be performed with fine‑pointed tweezers, grasping the tick close to the skin and pulling steadily without twisting.