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lone star tick

lone star tick (Amblyomma americanum)
Photo © James Gathany

Features and Behaviors

The adult lone star tick female is about 1/8-inch long unfed and can be about one-half inch or longer after feeding. The male ranges in size from less than one-tenth to about two-tenths inch in length. The nymph is about the size of a pinhead. The body is round and brown, and the female has a large, white spot on the back. Ticks have four pairs of legs (total of eight legs) in their adult form. The larval form of a tick has six legs.

Present from April through fall, all stages will feed on a variety of animals, including people. The life cycle can take up to three years. The adult female feeds, then lays eggs. The eggs hatch to the larval form. After feeding, the larval form transforms to the nymph. The nymph feeds, then molts to the adult form. Lone star ticks can transmit the pathogens for Rocky Mountain spotted fever, ehrlichiosis and tularemia. Although found statewide, this species is most common in the southern one-half of the state. Local health departments and the Illinois Department of Public Health (217-782-2016 or can provide more information about ticks and the diseases that they can carry.

Illinois Range


​Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Ixodida
Family: Ixodidae

Illinois Status: common, native