American dog tick vs Lone star tick
These two are easy to mix up. Here's how to tell a american dog tick from a lone star tick, and whether either one bites or stings.
American dog tick
Dermacentor variabilis
Lone star tick
Amblyomma americanum
≠The key differences
D. variabilis has white mottling on its back in both sexes and lacks the single central white female spot; mouthparts are shorter relative to body.
⚖︎Side by side
| American dog tick | Lone star tick | |
|---|---|---|
| To humans | Disease vector | Disease vector |
| Size | Unfed adults 3-5 mm long; engorged females up to about 15 mm | Unfed adults 3-6 mm; engorged females up to 15 mm or larger |
| Colours | Brown, Reddish-brown, Cream (pale ornamentation), Grey (engorged female) | Reddish brown, Cream/white (female spot), Pale mottling |
| Family | Ixodidae | Ixodidae |
| Habitat | Grassy fields, trails, forest edges, leaf litter and tall roadside vegetation; often found where mammals travel or rest. | Woodlands, brushy edges, overgrown fields, and areas with high deer or other wildlife activity; also lawns and trail margins near wooded areas |
| Range | Eastern and central United States and southern Canada, with separate populations along parts of the Pacific coast. | Originally southeastern and south-central USA, now widespread across the eastern and central United States and expanding northward, with occasional records in southern Canada |
| Active | Most active spring through early summer and in warm autumn periods; adults quest during daylight on warm, humid days. | Spring through fall in most of its range; adults and nymphs most active in warm months and on warm, humid days |
| Pest? | Yes | Yes |
🔍How to spot a american dog tick
- Hard, oval body with a dorsal scutum and visible mouthparts projecting forward.
- Adults 3-5 mm when unfed, females noticeably expand when engorged.
- Brown to reddish-brown color with lighter cream or buff ornamentation on the scutum (more obvious on males).
- Usually found questing on grass and low vegetation rather than high in trees.
🔍How to spot a lone star tick
- Female adults show a single distinct white or cream dorsal spot (the 'lone star') on an otherwise reddish-brown body.
- Males lack the single spot and have pale mottled markings across the scutum.
- Mouthparts are long and visible from above; adults have eight legs and a hard scutum.
- Size varies widely: unfed adults 3-6 mm, engorged females swell to over 10 mm.
?Frequently asked questions
What is the difference between a american dog tick and a lone star tick?
D. variabilis has white mottling on its back in both sexes and lacks the single central white female spot; mouthparts are shorter relative to body.
Is a american dog tick or a lone star tick more dangerous?
American dog tick: Disease vector. Lone star tick: Disease vector. Bites can cause localized irritation; more importantly, the species can transmit Rocky Mountain spotted fever and, less commonly, tularemia. Bites can be itchy and irritating and can transmit pathogens (notably ehrlichiosis and tularemia) and are associated with STARI.
Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.