Argasidae

Definition

A family of soft ticks (order Ixodida) characterized by a leathery, wrinkled integument lacking the hard scutum found in hard ticks (Ixodidae). Argasids possess a subterminal capitulum visible only from below, multiple nymphal instars (typically 2–7), and rapid feeding habits (minutes to hours versus days). The family comprises approximately 220 species in two recognized subfamilies (Argasinae, Ornithodorinae), with highest diversity in South Asia. Soft ticks exhibit exceptional desiccation resistance and longevity, surviving years without feeding in arid microhabitats.

Etymology

From genus Argas (Greek argos, 'bright' or 'swift') + family suffix -idae.

Example

Ornithodoros moubata, an argasid tick, transmits African swine fever virus to domestic pigs and relapsing fever spirochetes (Borrelia duttoni) to humans; its ability to survive months in dry burrows enables pathogen persistence between host encounters.

Synonyms

• soft ticks

Related Terms

• Ixodidae
• Ixodida
• Acari
• Parasitiformes
• Ornithodoros
• Argas
• Scutum
• capitulum
• Relapsing fever
• tick-borne disease

Usage Notes

Argasidae contrasts with Ixodidae (hard ticks) in morphology, feeding duration, and habitat preference. Argasids are often nest- or burrow-dwelling, feeding intermittently on roosting birds or sheltering mammals, whereas ixodids typically quest in vegetation. The common name 'soft tick' refers to the flexible, unarmored body; however, this is a relative distinction—some argasids are quite sclerotized. Taxonomic composition remains provisional; molecular studies continue to refine generic boundaries within Argasinae and Ornithodorinae.