spinose ear tick
Otobius megnini
This record describes Otobius megnini (species). Recorded family: Argasidae. Recorded order: Ixodida.
Identification and Appearance
Classification
Habitat and Range
Habitat
Larvae and nymphs live within the ear canal of the mammalian host. Adults are non-parasitic. Documented hosts include: cattle, cats, sheep, horses and other equines, goats, swine, coyotes, deer, bighorn sheep, cottontail rabbits, jackrabbit, ostrich, javelina, and pronghorn; rare zoonotic infection in humans. Most common in arid regions.
Geographic Range
western and southwestern United States, south to Argentina, Brazil, and Chile; introduced to India, Australia, and South Africa.
Diet and Behavior
Diet: Blood of the mammalian host (see also habitat, above).
Life History
Eggs of Otobius megnini are laid on or near the ground for as long as 6 months. They hatch in 18 days or more. The larvae then crawl up vegetation, fence posts and feed bunks to await hosts. Unfed larvae may live off the host for more than 2 months. If they find host, they locate in the ears where they engorge for 5 to 10 days. The larvae molt to the nymphal stage in the ears. Here they engorge for about a month. However, the nymphs may remain in the ear for as long as 7 months. When ready to molt, they crawl out of the ears to the ground where they molt to adults. This species is a one-host tick.
About Ticks: the wider group
Order-level background for Ixodida, the group containing Otobius megnini. Species-specific details appear above.
Group overview
Ixodida (ticks) includes ~900 described species in two major families: hard ticks (Ixodidae, ~700 species) and soft ticks (Argasidae, ~200 species). Ticks can increase their body weight by 200-600× when engorged with blood.
Ecological role of the group
Ticks are obligate blood-feeding parasites at all life stages after hatching. A single female can lay 3,000-8,000 eggs. Ticks can transmit more different pathogens than any other arthropod group - including bacteria, viruses, and protozoa simultaneously.
Economic and practical significance of the group
Tick-borne diseases are the most common vector-borne illnesses in the U.S. - Lyme disease alone accounts for 82% of all tickborne disease reports (CDC). Annual cases more than doubled from 22,000 to 48,000 between 2004-2016. Tick-related economic losses in U.S. cattle alone exceed $3 billion annually.
Recorded sources for this group: CDC tick surveillance data, USDA veterinary entomology. Imported estimates may describe particular regions or reporting periods.
Photos of spinose ear tick (5)
Photo credits: Contributed by Blaine Mathison
Frequently Asked Questions About spinose ear tick
Where is spinose ear tick found?
| Feature | Details |
|---|---|
| Habitat | Larvae and nymphs live within the ear canal of the mammalian host. Adults are non-parasitic. Documented hosts include: cattle, cats, sheep, horses and other equines, goats, swine, coyotes, deer, bighorn sheep, cottontail rabbits, jackrabbit, ostrich, javelina, and pronghorn; rare zoonotic infection in humans. Most common in arid regions. |
| Range | western and southwestern United States, south to Argentina, Brazil, and Chile; introduced to India, Australia, and South Africa. |
What does spinose ear tick eat?
The diet of the spinose ear tick includes Blood of the mammalian host (see also habitat, above)..
What is the life cycle of a spinose ear tick?
Eggs of Otobius megnini are laid on or near the ground for as long as 6 months. They hatch in 18 days or more. The larvae then crawl up vegetation, fence posts and feed bunks to await hosts. Unfed larvae may live off the host for more than 2 months. If they find host, they locate in the ears where they engorge for 5 to 10 days. The larvae molt to the nymphal stage in the ears. Here they engorge for about a month. However, the nymphs may remain in the ear for as long as 7 months. When ready to molt, they crawl out of the ears to the ground where they molt to adults. This species is a one-host tick.