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How to identify it
- A hard tick in the genus Ixodes that researchers describe as morphologically very similar to the blacklegged tick.[3][1]
- The two species share the mid- and south-Atlantic coastal states, and researchers developed a DNA test that tells them apart at every life stage as a supplement to examining the ticks under magnification.[3]
- Only ticks in the genus Ixodes can transmit the bacterium that causes Lyme disease, and researchers call accurate identification of these two species crucial to disease studies in the region. Because Ixodes affinis adults are active from April to November in North Carolina, suspected Lyme vectors collected there in warm months need a confirmed identification.[7][3][1]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Blacklegged tick | Shares the coastal Southeast with Ixodes affinis and is very similar in form; adult blacklegged ticks have a reddish-orange body, black legs and a black shield. Among Ixodes ticks taken from southeastern dogs and cats in one national study, about 93 percent were blacklegged ticks and 3.5 percent were Ixodes affinis.[3][7][4] |
| Groundhog tick | Another Ixodes found on southeastern pets: the same study identified 10 groundhog ticks from 3 dogs, alongside the 9 Ixodes affinis.[4] |
Where it lives
Ixodes affinis lives in the coastal plain of the southeastern United States. In North Carolina it has been collected in 32 of the state's 41 coastal plain counties but in no piedmont or mountain county, a pattern like its distribution in Georgia and South Carolina. It is expanding northward, and newly established populations in southeastern Virginia mark the northern edge of its range. Published records from dogs and cats come from Virginia, North Carolina, South Carolina, Georgia and Florida.[1][2][4]
Biology and life cycle
In southeastern Virginia, the highest densities were in mixed pine and hardwood forest with an herbaceous understory. It was never found in the smallest habitat patches or in dry dune habitat, and once a population became established it tended to persist and grow as the forest matured, provided the understory stayed vegetated.[2]
Known hosts in the United States numbered 15 mammal species and one bird species as of 2010. Later work in Virginia added house mice and coyotes, hosts that may help the tick keep spreading and sustain new populations.[1][2]
In North Carolina, adults are out seeking hosts from April to November.[1]
Damage and signs
- It feeds on dogs and cats. In a national survey of Ixodes ticks from pets, 9 of the 261 from the Southeast were Ixodes affinis, taken from 2 cats and 5 dogs, and earlier reports document it on pets in Virginia, North Carolina, South Carolina, Georgia and Florida.[4]
- It has also been recorded biting people. A 2022 review lists it as one of only three tick species added after 2000 to the list of ticks known to infest humans in the United States.[5]
Health risk
In the coastal plain of Georgia and South Carolina, Ixodes affinis is considered an enzootic vector of Borrelia burgdorferi sensu stricto, the Lyme disease bacterium, and researchers describe it, like the blacklegged tick, as a tick vector of that bacterium. Its northward spread is changing tick community dynamics in the Mid-Atlantic. For pets, Ohio State Extension advises testing dogs for exposure to tick-borne diseases at annual checkups, or right away if symptoms appear, and having any pet with symptoms examined by a veterinarian.[1][3][2][6]
Control
Prevention
In wooded tick habitat, wear light-colored clothing so crawling ticks are easier to see, tuck pants into socks and shirt into pants, and apply a tick repellent following the manufacturer's instructions. Ohio State notes that DEET products need at least 25 percent DEET to repel ticks and that permethrin repellents go on clothing only, never on skin.[6]
Sanitation
Clearing brush, tall weeds and grass removes cover for the rodents and other small mammals that ticks feed on.[6]
Traps and physical control
Check yourself and your pets for ticks often, and remove any attached tick right away.[6]
When to call a professional
Tick-control products for dogs are available from veterinarians, and Ohio State recommends consulting your veterinarian before using any over-the-counter product.[6]
Common questions
- Is Ixodes affinis the same as a deer tick?
- No, but it is very similar. It is a separate species that looks so much like the blacklegged (deer) tick that researchers developed a DNA test to tell them apart, and both are vectors of the Lyme disease bacterium.[3]
- Is Ixodes affinis spreading?
- Yes. It is expanding its range northward, and newly established populations in southeastern Virginia, at the northern edge of its range, tend to persist once they take hold.[2]
- Does it bite dogs and cats?
- Yes. It has been found on dogs and cats from Virginia to Florida, including 2 cats and 5 dogs in a recent national survey of ticks from pets.[4]
Sources
- Journal of Vector Ecology (Society for Vector Ecology), “Recent discovery of widespread Ixodes affinis (Acari: Ixodidae) distribution in North Carolina with implications for Lyme disease studies (B.A. Harrison and others), Journal of Vector Ecology 35(1):174-179 (2010), abstract.” pubmed.ncbi.nlm.nih.gov/20618664/ (accessed 2026-11-08)
- Ticks and Tick-borne Diseases (Elsevier), “Natural history of Ixodes affinis in Virginia (R.M. Nadolny and H.D. Gaff), Ticks and Tick-borne Diseases 9(1):109-119 (2018), abstract.” pubmed.ncbi.nlm.nih.gov/29030315/ (accessed 2026-11-08)
- Ticks and Tick-borne Diseases (Elsevier), “Single-tube real-time PCR assay for differentiation of Ixodes affinis and Ixodes scapularis (C.L. Wright and others), Ticks and Tick-borne Diseases 5(1):48-52 (2014), abstract.” pubmed.ncbi.nlm.nih.gov/24192510/ (accessed 2026-11-08)
- Vector-Borne and Zoonotic Diseases (Mary Ann Liebert), full text in PubMed Central PMC9469741, “Ixodes spp. from Dogs and Cats in the United States: Diversity, Seasonality, and Prevalence of Borrelia burgdorferi and Anaplasma phagocytophilum (P. Ghosh et al.), Vector-Borne and Zoonotic Diseases 21(1):11-19, 2021.” pmc.ncbi.nlm.nih.gov/articles/PMC9469741/ (accessed 2026-11-08)
- Ticks and Tick-borne Diseases (Elsevier), full text in PubMed Central PMC10862467, “Tick species infesting humans in the United States (L. Eisen), Ticks and Tick-borne Diseases 13(6):102025, 2022.” pmc.ncbi.nlm.nih.gov/articles/PMC10862467/ (accessed 2026-11-08)
- Ohio State University Extension (Ohioline), “Ticks and Tick-Borne Diseases, HYG-2073.” ohioline.osu.edu/factsheet/HYG-2073 (accessed 2026-11-08)
- University of Kentucky Entomology Extension, “Ticks and Disease in Kentucky, ENTFACT-618.” entomology.ca.uky.edu/ef618 (accessed 2026-11-08)
- iNaturalist, “Ixodes affinis taxon page (order and family).” www.inaturalist.org/taxa/297828 (accessed 2026-11-08)