Dermacentor variabilis

Definition

A species of hard tick (family Ixodidae) native to eastern North America, commonly called the American dog tick or wood tick. Adults feed primarily on medium to large mammals, including dogs and humans, and are principal vectors of Rickettsia rickettsii (Rocky Mountain spotted fever) and Francisella tularensis (tularemia). Larvae and nymphs typically parasitize small mammals and ground-dwelling birds. The species is among the most medically important ixodid ticks in the United States due to its broad host range and synanthropic tendencies.

Etymology

Latin: Dermacentor, 'skin pricker' (from derma 'skin' + kentor 'stinger'); variabilis 'variable,' likely referring to morphological variation or host plasticity.

Example

Field surveys for Dermacentor variabilis often focus on woodland edges and grassy trails where questing adults climb vegetation to encounter hosts; nymphal stages are frequently recovered from white-footed mice (Peromyscus leucopus) using drag sampling or nest box inspections.

Synonyms

• American dog tick
• wood tick

Related Terms

• Ixodidae
• Rickettsia rickettsii
• Rocky Mountain spotted fever
• Tularemia
• questing behavior
• three-host tick
• vector competence
• tick-borne disease

Usage Notes

Distinguish from Dermacentor andersoni (Rocky Mountain wood tick), a western North American congener that also vectors RMSF but occupies different elevation and habitat zones. The name 'wood tick' is sometimes applied loosely to several Dermacentor species; precise identification requires examination of scutal ornamentation and spiracular plate shape. Specimens identified as 'Dermacentor variabilis Camicas et al., 1998' in some databases represent a separate taxonomic act and may require verification against the senior synonym Say, 1821.