Mosquito Distributions Across Delaware

• Joshua Hornberger, Insect Ecology and Conservation, University of Delaware

• Vincenzo Ellis, Entomology and Wildlife Ecology, University of Delaware

Mosquitoes are a global public health concern causing upwards of 700,000 deaths per year (World Health Organization, 2025). Risk of mosquito-borne disease is determined in large part by the species of mosquitoes in an area, as species differ in vector competence and ecology. The composition and distribution of mosquito species in Delaware is largely unknown, which leaves the state unaware of potential mosquito-borne disease risk or how to effectively control mosquito populations. The most common locally transmitted mosquito-borne disease in the state is West Nile virus, with a few cases each year, but the state also monitors for eastern equine encephalitis, as well as tracking exposure risks for disease from neighboring states that have the potential to be vectored in Delaware (Delaware Department of Natural Resources and Environmental Control [DNREC], 2026). Understanding mosquito distributions across the state is important for protecting against mosquito-borne diseases and deploying effective control strategies. The Mosquito Control Section of DNREC’s Division of Fish and Wildlife set CDC light traps at 32 locations for weekly mosquito surveillance from May to October in 2025. This project will use this data to map and interpret mosquito distributions in R. When complete, this project will present essential information on the current distributions of Delaware’s mosquitoes which can improve our knowledge on potential disease risk throughout the state.