- An acarine of the families Ixodidae (hard ticks) or Argasidae (soft ticks), which contain many bloodsucking species that are important pests of humans and domestic birds and mammals, and that probably exceed all other arthropods in the number and variety of disease agents that they transmit. Ticks are differentiated from the much smaller true mites by possession of an armed hypostome and a pair of tracheal spiracular openings located behind the basal segment of the third or fourth pair of walking legs; the larva (seed t.) has six legs, and after molting appears as an eight-limbed nymph. Some important ticks are Amblyomma americanum (Lone Star t.) and A. hebraeum (South African bont t.); Argas persicus (adobe, fowl, or Persian t.) and A. reflexus (pigeon t.); Boophilus (cattle ticks); Dermacentor albopictus (horse or winter t.), D. andersoni (Rocky Mountain spotted fever or wood t.), D. nitens (tropical horse t.), D. occidentalis (Pacific or wood t.), and D. variabilis (American dog t.); Haemaphysalis chordeilis (bird t.) and H. laporis-palustris (rabbit t.); Ixodes pacificus (California black-legged t.), I. pilosus (paralysis t.), I. ricinus (castor bean t.), and I. scapularis (black-legged or shoulder t.); Ornithodoros coriaceus (pajaroello t.) and O. moubata (African relapsing fever or tampan t.); and Rhipicephalus everti (African red t.), R. sanguineus (brown dog t.), and R. simus (black-pitted t.).
* * *tick 'tik n1) any of numerous bloodsucking arachnids that constitute the acarine superfamily Ixodoidea, are much larger than the closely related mites, attach themselves to warm-blooded vertebrates to feed, include important vectors of various infectious diseases of humans and lower animals, and although the immature larva has but six legs, may be readily distinguished from an insect by the complete lack of external segmentation2) any of various usu. wingless parasitic dipteran flies (as the sheep ked)
* * *n.a bloodsucking parasite belonging to the order of arthropods (the Acarina) that also includes the mite. Tick bites can cause serious skin lesions and occasionally paralysis (see Ixodes, Amblyomma), and certain tick species transmit typhus, Lyme disease, and relapsing fever. Dimethyl phthalate is used as a tick repellent. There are two families: Argasidae (soft ticks), which includes Ornithodoros, with mouthparts invisible from above and no hard shield (scutum) on the dorsal surface; and Ixodidae (hard ticks), including Dermacentor, Haemaphysalis, and Rhipicephalus, with clearly visible mouthparts and a definite scutum.
* * *(tik) a blood-sucking, parasitic arachnid arthropod of the suborder Ixodides, superfamily Ixodoidea. The ticks are larger than their relatives, the mites. There are two families: Argasidae (soft ticks) and Ixodidae (hard ticks).
Medical dictionary. 2011.