Variable Rates of Parasitism on Ornate Box Turtles (Terrapene ornata) in Eastern Kansas by the Chelonian-Specific Ectoparasite Cistudinomyia cistudinis

Abstract. – Understanding which factors make an individual susceptible to parasitism provides insight on how a parasite infects a host. Numerous factors such as habitat characteristics, body size, and sex have shown differential impacts on parasitism rates. Trends in parasitism rate often exist for similar taxonomic groups, so expanding research to new species helps test the robustness of such trends. A chelonian-specific ectoparasite, Cistudinomyia cistudinis (Diptera: Sarcophagidae), has been documented in case studies dating back a century. Almost all reports of infection by this flesh fly are of a single or few turtles, so there is a lack of information regarding the population dynamics of infection. This lack of information means little is known about which factors make a turtle more or less likely to be parasitized. In this work, we compared the occurrences of parasitism in ornate box turtle (Terrapene ornata) populations across multiple seasons from 2 different habitats in northeastern Kansas (North Topeka and Lawrence). At the population level, we found a significantly higher number of parasitized turtles in the Lawrence population. Within the Lawrence population, we found females were more likely to be parasitized. This study sets baseline infection rates for a long-lived vertebrate host that can help better understand the reasons for parasitism both among and within populations.