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Asian Longhorned Tick in Delaware
Invasive tick found in New Castle and Kent counties. Rarely bites people; hard on livestock.
| Peak season | Apr – Aug |
|---|---|
| Size | About 0.1 inch (unfed) |
| Risk | Livestock risk — heavy infestations; rarely bites people |
How to identify them
A small, solid-colored reddish-brown tick, about 0.1 inch long, with no contrasting markings on the back. DNREC lists three features to look for: short mouthparts, a solid color with no contrast between the shield and the rest of the body, and projections on the mouthparts that stick out to the sides. Immature ticks can be smaller than a sesame seed; a female full of blood is about the size of a pea.
Asian Longhorned Tick in Delaware
DNREC first confirmed the Asian longhorned tick in Delaware in 2019, after tick surveillance found five nymphs in northern New Castle County in late June. It is now found in a variety of habitats in New Castle and Kent counties during the spring and summer. In the U.S., females can lay eggs without mating, so a single tick can start a new population. The tick is known to swarm livestock and horses in large numbers, causing serious blood loss.
When they’re active
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What you can do now
- Use an EPA-registered repellent and treat clothing with permethrin. Wear long sleeves and tuck pants into socks or shoes.
- Check yourself, kids and pets daily after time outdoors, and shower soon after coming inside.
- Keep grass mowed and clear leaf piles. Penn State Extension suggests a 9-foot buffer between lawn and wooded edges.
- Ask your veterinarian about tick protection for pets, and check livestock regularly.
Reporting a tick and getting help
Report suspected Asian longhorned ticks to DNREC through the Tick Interaction Report at de.gov/ticks; a photo of the top of the tick helps. USDA APHIS suggests sealing a suspect tick in a zip-top bag and giving it to your veterinarian for identification. Delaware does not offer tick pathogen testing. Livestock and horse owners should talk to their veterinarian about prevention.
Asian Longhorned Tick: common questions
Can the Asian longhorned tick make me sick?
DNREC says it infrequently bites people and, so far, isn’t associated with any medical conditions in the United States, though elsewhere in the world it has been linked to conditions such as alpha-gal syndrome. The CDC says it isn’t yet known whether, or how often, these ticks pass pathogens to people.
Where in Delaware is it found?
DNREC first found it in northern New Castle County in June 2019. It is now found in a variety of habitats in New Castle and Kent counties during the spring and summer.
I think I found one. What should I do?
Seal it in a zip-top bag or take a clear photo of the top of the tick, then submit it through DNREC’s Tick Interaction Report at de.gov/ticks. If it was on a pet or livestock, contact your veterinarian.
Where in Delaware
DNREC reports longhorned ticks in a variety of habitats in New Castle and Kent counties during the spring and summer. They were first found in Delaware in late June 2019, in northern New Castle County.
Where Asian longhorned ticks rank on each county’s top-pest list:
- New Castle County Not in the county top six
- Kent County Not in the county top six
- Sussex County Not in the county top six
Towns where Asian longhorned ticks are on the local top-pest list: