Date of Award

Spring 3-30-2022

Document Type

Honors Thesis



First Advisor

Dr. Hugh Britten

Second Advisor

Dr. Jose Pietri

Third Advisor

Dr. Mark Sweeney


South Dakota, Ixodes scapularis, Borrelia, Lyme, infection, expansion, Amblyomma americanum

Subject Categories

Entomology | Epidemiology | Veterinary Preventive Medicine, Epidemiology, and Public Health


Tick-borne diseases threaten the health of humans, animals, and ecosystems, but surveillance efforts are lacking in some regions. Throughout 2019, 2020, and 2021, we conducted tick surveys aimed at determining the status of the black-legged tick (Ixodes scapularis), the American dog tick (Dermacentor variabilis) and the lone star tick (Amblyoma americanum) in eastern South Dakota. Each year, ticks were collected using a flagging method and identified in the lab. A subset were tested for the presence of Borrelia burgdorferi, the causative agent of Lyme disease, by polymerase chain reaction (PCR). Dermacentor variabilis was the most commonly identified tick, present in all counties surveyed. Amblyomma americanum was also identified in three counties, providing the first evidence of established populations in the state and expanding the range of this species. In addition, established populations of Ixodes scapularis were identified in three counties, confirming a previous report of an established population in the state. Adult I. scapularis from Lincoln and Clay Counties were found to harbor B. burgdorferi during each surveillance year, suggesting the ongoing presence of the pathogen in tick populations in the state and representing its southwestern-most detection in the Midwest United States. These findings provide important information for assessing and monitoring the public health risk from tick-borne diseases in an area with minimal surveillance.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.