Spinose ear tick

Definition

A soft-bodied argasid tick (Otobius megnini) whose larval and nymphal stages are obligate parasites of the external ear canal in mammals. Unlike most ticks, adults are non-parasitic and do not feed; only the immature stages infest hosts, causing otitis externa, secondary infections, and sometimes fatal neurologic complications in heavy infestations. The name refers to the spiny cuticular projections visible on nymphs.

Etymology

From Latin spinosus (spiny, thorny) + ear, referring to the spiny integument of nymphs and the tick's exclusive infestation site; specific epithet honors French veterinarian L. Megnin.

Example

In feedlot cattle, heavy infestations of spinose ear ticks can cause head shaking, ear drooping, and weight loss; control requires acaricide treatment of the ear canal rather than whole-body application.

Synonyms

• Otobius megnini

Related Terms

• Argasidae
• soft tick
• otitis externa
• Nidicolous
• Argasid
• ear mite
• Otobius

Usage Notes

Strictly refers to Otobius megnini, not to other ticks occasionally found in ears (e.g., some Ixodes species). Distinguish from ear mites (Otodectes cynotis, arachnids but not ticks). The non-feeding adult stage is diagnostic for Otobius and unusual among ticks.