Dermacentor variabilis, American Dog Tick, SEM

american dog tick arachnid arthropod vector arthropod blue disease d variabilis dermacentor variabils dermacentor disease epromo05072018b f tularensis female francisella tularensis hard tick illness insect borne ixodidae parasite parasitiformes parasitology r rickettsii rickettsia rickettsii rickettsia rickettsial rmsf rocky mountain spotted fever tick tick borne tularemia vector borne wood tick zoonosis