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Delaware

Lone Star ticks in New Castle County

CDC county record, 2025

Yes. Lone Star ticks have been found in New Castle County.

Lone Star ticks have been found here, but fewer than CDC needs to call them established. Treat them as present and take the usual steps outdoors. The nearest county where CDC lists them as established is Cecil County, MD, about 15 miles away, measured between centers. CDC county data, 2025 (opens in a new tab)

Peak season
April – SeptemberNo state figure; CDC's national guide: CDC (opens in a new tab)
What to do
Use repellent and do tick checks. If you ever get hives or stomach pain hours after eating red meat, mention tick bites to a clinician.
All of Delaware
Alpha-gal hotspotCDC lists 2 of Delaware's 3 counties as established and 1 more as reported.Ticks in Delaware

Loading counties…

Fig. 1. New Castle County, outlined in ink, among Delaware’s 3 counties, by CDC’s 2025 record.
  • Established2
  • Reported1
  • No records0

If you find one on you

Take it out with fine-tipped tweezers, pulling straight up, and write down the date. The step-by-step guide tells you what to watch for, and for how long.

What to do after a biteIdentify the tick

How to avoid bites in New Castle County

  • Use EPA-registered repellent (DEET, picaridin, or oil of lemon eucalyptus)
  • Treat clothing and gear with permethrin
  • Wear long sleeves and tuck pants into socks in brushy areas
  • Stay on cleared trails and avoid tall grass and leaf litter
  • Shower within two hours of coming indoors
  • Do daily tick checks on people and pets during the season
The full prevention guide

Common questions

Are there Lone Star ticks in New Castle County, Delaware?

CDC's 2025 county record for New Castle County says "Reported". Lone Star ticks have been found here, but fewer than CDC needs to call them established. Ticks are most active from April to September. Finding ticks is not the same as personal disease risk.

How far is New Castle County from where Lone Star ticks are established?

Lone Star ticks have been reported in New Castle County itself, though not in the numbers CDC counts as established. The nearest county where CDC lists them as established is Cecil County, MD, about 15 miles from New Castle County, measured between centers.

When is tick season in New Castle County?

In Delaware, Lone Star ticks are most active from April to September. They can still bite on warm days outside those months, so keep up tick checks.

Can a tick bite in New Castle County cause alpha-gal syndrome?

It can. Lone Star tick bites are linked to alpha-gal syndrome, a delayed allergy to red meat. Most bites do not cause it, and only a doctor can diagnose it. Watch for hives, swelling or stomach trouble 2 to 6 hours after eating red meat.

What should I do if I find a tick in New Castle County?

Remove it with fine-tipped tweezers, pulling straight up with steady pressure, then clean the area. Save a photo, note the date, and watch for symptoms over the following weeks. Contact a licensed clinician if a rash, fever, fatigue, or a delayed reaction to red meat develops.

How do I report or identify a tick found in New Castle County?

Save the tick in a sealed bag with a moist paper towel and take a clear photo. Your Delaware health department or a university extension program may identify or test it. LoneStarMap does not collect tick reports. Official surveillance runs through those agencies.

Where this comes from8 sourcesShow
  1. 1.
    Where Ticks Live (opens in a new tab) · CDC

    The Lone Star tick is widely distributed in the Northeast, South, and Midwest U.S.

  2. 2.
    Lone Star Tick Surveillance (opens in a new tab) · CDC

    County-level established vs. reported records. 'Established' = 6+ ticks or multiple life stages collected in 12 months.

  3. 3.
    Alpha-gal Syndrome (opens in a new tab) · CDC

    What alpha-gal syndrome is, symptoms, and its association with tick bites.

  4. 4.
    Geographic Distribution of Suspected Alpha-gal Syndrome Cases — U.S., 2017–2022 (MMWR) (opens in a new tab) · CDC / MMWR

    Highest suspected-AGS prevalence across a contiguous southern, midwestern, and mid-Atlantic region; most cases align with the established Lone Star tick range.

  5. 5.
    Current and Future Distribution of the Lone Star Tick in North America (opens in a new tab) · Raghavan et al., PLOS ONE (2019)

    Ecological niche modeling of Amblyomma americanum range and projected northward expansion.

  6. 6.
    Preventing Tick Bites (opens in a new tab) · CDC
  7. 7.
    Find the Repellent That Is Right for You (opens in a new tab) · EPA

    Search tool for EPA-registered repellents (DEET, picaridin, oil of lemon eucalyptus).

  8. 8.
    Lone Star Tick Surveillance Map Data, 2025 (county status) (opens in a new tab) · CDC

    Every county's status: Established (6 or more ticks, or more than one life stage, found in a year), Reported (fewer), or No records. Linked from CDC's Lone Star Tick Surveillance page.

Regional data last reviewed:

Educational information only, not medical advice. If someone is struggling to breathe or having a severe reaction, call 911. Read the disclaimer.

Printed from lonestarmap.com/states/delaware/new-castle. Check the page for the latest version.