acase@tulane.edu / The United States is home to eleven species of triatomine insects that can carry and transmit the parasite that causes Chagas disease, Trypanosoma cruzi. Much of the natural history of these vectors remains unknown. This is especially true of the species native to southeastern Louisiana, Triatoma sanguisuga. To this end experiments were undertaken to understand the movements, blood meal sources, and associated vertebrates of T. sanguisuga. Sites of genetic variability were sequenced and compared to determine how related T. sanguisuga spatially aggregate. It is demonstrated that the cytochrome b gene can be used to identify sub-populations of these insects and monitor their spatial aggregation over a multi-year period. Genetic analysis suggests the presence of wide-spread sub-populations. The sources of vertebrate blood meals were determined from collected specimens to determine the most frequent bloodmeal sources. The most frequent bloodmeal sources were found to be from humans, cows, pigs, dogs, and raccoons - though some of these sequences are likely the result of laboratory contamination. Finally, habitat modeling of T. sanguisuga provides a framework for assessing the shared habitats of T. sanguisuga and its vertebrate food sources. By using publicly available reports of T. sanguisuga, a model representing suitable habitat for the vector was created. By comparing this distribution to similar distribution models of associated animals, it was determined that the most statistically significant overlap of suitable habitats occurs between T. sanguisuga and two small rodent species, Oryzomys palustris and Neotoma floridana. The present research adds significantly to the limited knowledge of the natural history of this vector species. The work provides a foundation on which to build evidence-based risk assessments of autochthonous human Chagas disease in southeastern Louisiana and beyond. / 1 / Samuel B Jameson