P9 - Lyme Disease Vector Geographic Range Expansion: South Carolina is a Battleground of Northern and Southern Ixodes scapularis clade colonization into new ecosystems

Abstract: Recent evidence indicates two subclades of blacklegged tick (Ixodes scapularis) exist in the USA: a northern and southern clade. Northern clade ticks exhibit more aggressive host seeking characteristics, making this subclade a public health priority. With factors such as climate change, urbanization, host movement, and variations in ecological populations, South Carolina has become a battleground for this Lyme disease vector, with both subclades encroaching along the Appalachian Mountains or Atlantic coast. Small genetic difference between the ticks migrating from the south versus the north may help researchers make important predictions about their settlement in the southeastern USA, and what implications this may have on public health and vector control agencies. The current study leverages 450 banked Ixodes scapularis tick samples from across South Carolina to employ a multi-year phylogenic analysis to detail subclade spatial-temporal distribution. We hypothesize the state will become divided with established northern clade I. scapularis in the Upstate region, southern clade I. scapularis in the low country region, and focal variances of both clades in the PeeDee and Midlands regions dependent on underlying deer population abundance and environmental characteristics.