soft ticks

Definition

Members of the family Argasidae, one of three extant families of ticks (suborder Ixodida), distinguished by a leathery, wrinkled integument lacking the hard scutum (dorsal shield) characteristic of hard ticks (Ixodidae). Soft ticks possess a subterminal capitulum (mouthparts) hidden from dorsal view, are adapted to arid environments with exceptional desiccation resistance, and typically exhibit rapid feeding (minutes to hours) and multiple nymphal instars. The family comprises approximately 220 species in genera including Argas, Ornithodoros, and Otobius, with highest diversity in South Asia. Many species are nidicolous, residing in host nests, burrows, or roosts, and several transmit pathogens including tick-borne relapsing fever spirochetes (Borrelia spp.) and African swine fever virus.

Etymology

Common name refers to the flexible, unarmored cuticle contrasting with the sclerotized scutum of hard ticks.

Example

Ornithodoros moubata, a soft tick of African rodent burrows, transmits Borrelia duttonii, the agent of endemic relapsing fever, and can survive years without feeding in desiccated conditions.

Synonyms

• Argasidae

Related Terms

• hard ticks
• Ixodidae
• Scutum
• capitulum
• Nidicolous
• Relapsing fever
• tick-borne disease
• ixodid
• Argasid
• festoon

Usage Notes

The term is strictly common-name equivalent to the family Argasidae, not a grade or ecological grouping. Soft ticks differ from hard ticks in habitat use (often cryptic, nest-dwelling vs. questing), feeding duration, and life-history traits; these distinctions are functionally significant in disease ecology and control. The adjective 'soft' describes integument texture, not body consistency in living specimens. In formal taxonomic contexts, 'Argasidae' is preferred.