Lone star tick. Engorged female lone star tick (Amblyomma americanum). Some freshly laid eggs (orange spheres) are seen to the right of the tick's head. A. americanum is found through the southeast and south-central United States. It is the vector for the spirochete bacteria Borrelia lonestari, which causing a Lyme disease-like rash known as southern tick-associated rash illness (STARI).