First Evidence of an Established Population of Ixodes scapularis (Acari: Ixodidae) in South Dakota.

Ixodes scapularis Say (Acari: Ixodidae) is the most important vector of human disease in the United States. Recent efforts by public health officials to determine its presence on a county-by-county basis have been undertaken to assist in Lyme disease risk assessment. Recent modeling efforts show that South Dakota can potentially support populations of I. scapularis based on favorable climatic conditions and presence of suitable hosts to support tick populations within the state. We provide the first documentation of an established population of I. scapularis in Clay County, SD, providing only the third record of the presence of this tick species within the state.