The family Ixodidae (hard ticks) is by far the largest and economically most important family with 13 genera and approximately 650 species.
The most important species of hard ticks in North America as parasites of companion animals are:
Ixodes pacificus, Ixodes scapularis (dammini) (Black-legged (Deer) tick), Dermacentor variabilis (American dog tick), Rhipicephalus sanguineus (Brown dog tick) and Amblyomma americanum (Lone star tick), Haemaphysalis leporispalustris, Boophilus annulatus and Boophilus microplus.
I. ricinus (Castor bean tick, sheep tick) a prostriate tick, is the most common tick in Northern Europe and is an important vector of both animal and human diseases.
The family Argasidae (soft ticks) comprises 5 genera and approximately 170 species.
The 5 genera are: Argasinae (e.g. Argas reflexus, Argas vespertilionis), Ornithodorinae (e.g. Ornithodoros hermsi, Ornithodoros coriaceus, Ornithodoros moubata), Otobinae (e.g. Otobius megnini), Antricolinae, Nothoaspinae.