Amblyomma americanum

Photo by CDC: Adult Female Lone Star Tick

This hard tick is a rare visitor to Colorado and is probably not an established resident, but arrives occasionally on animals traveling with their owners from the eastern US, where it has an extensive and expanding distribution, extending from Florida to Maine and as far west as Texas and Oklahoma. The adult female is distinguished by a white dot or “lone star” on her back. The lone star tick can transmit the agents of canine and human monocytic ehrlichiosis (HME), canine and human granulocytic ehrlichiosis (HGE), Tularemia, Q-fever and southern tick-associated rash illness (STARI); it has also been implicated in transmission of the Heartland and Bourbon viruses. The bite of this tick may also cause potentially fatal host paralysis via toxins in their saliva, and appear to cause red meat allergies in some people. Hosts of this species include a wide variety of mammals and ground-dwelling birds. The nymph and adult females are the most common biters. This is an aggressive tick that frequently bites humans.

Visit University of Rhode Island’s TickEncounter Resource Center for additional photos to help in the identification of ticks.

CDC Distribution Map: This map provides general insight into the expected distribution of these human-biting ticks in the contiguous United States. Populations of ticks may be found outside noted areas. Naturally occurring populations of the Lone Star Tick are not known to occur in Alaska or Hawaii.