Mosquito diversity, range-expanding species, and host-feeding patterns across Virginia's heterogeneous landscapes

Understanding how mosquito community, host use, and environmental drivers vary across landscapes is critical for predicting vector‑borne disease risk. Virginia spans multiple ecoregions and broad elevational gradient, yet statewide surveillance remains limited and concentrated near urban centers. To address surveillance gaps, we surveyed mosquitoes across four ecologically distinct sites in Virginia during 2022 to evaluate species diversity, bloodfeeding patterns, and environmental predictors of occurrence. Using CDC light traps, gravid traps, and supplemental aspiration, we collected 7,781 mosquitoes representing 34 species. Community composition varied significantly among sites: the Coastal Plain exhibited the greatest abundance and richness, while montane and urban sites supported lower but distinct assemblages. Several medically important and invasive species-including Aedes albopictus (Skuse), Aedes japonicus (Theobald), Culex pipiens/quinquefasciatus, Culiseta inornata (Williston), and the range-expanding Culex coronator (Dyar & Knab) and Culex nigripalpus (Theobald) were detected, providing new regional records beyond previously documented localities. Bloodmeal analysis from 18 specimens revealed predominantly mammalian feeding, with white‑tailed deer (Odocoileus virginianus [Zimmermann]) comprising over 80% of identified hosts across taxa. Avian and amphibian hosts occurred at lower frequencies, indicating diverse host-vector interactions relevant to enzootic transmission. Random forest models identified elevation and trap type as the strongest predictors of species-specific occurrence, with climatic factors exerting secondary effects. Together, these findings show that mosquito distribution and host selection in Virginia are shaped by interacting ecological and environmental drivers, underscoring the need for expanded, ecologically informed surveillance to improve assessments of vector‑borne disease risk in the region.