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

Ixodes scapularis</it> 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</it> 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</it> in Clay County, SD, providing only the third record of the presence of this tick species within the state.