First characterization of mosquito vector abundance and diversity on commercial swine farms in the United States

This study is the first in the United States to characterize mosquito vector abundance and diversity on commercial swine farms. Between June and October 2024, bi-weekly mosquito sampling was conducted on ten farms (five sow farms and five wean-to-market farms (WTM)) in southeast Iowa using BG-Pro light traps (Biogents AG, Regensburg, Germany). Traps were placed both outdoors, near water bodies (lagoons and ponds) and vegetation (crop fields, trees, shrubs, and thick grasses), and indoors (barns), trapping a total of 11,343 female mosquitoes. Overall, 55.8% were trapped on sow farms and 44.2% on WTM farms. Overall female abundance varied significantly across time periods (P < 0.01), peaking in July and August. Outdoor female abundance was significantly higher than indoors on sow farms (P < 0.01), whereas no statistically significant difference was observed on WTM farms. Nineteen mosquito species were identified, predominantly belonging to three genera: Culex, Aedes, and Anopheles, with significant differences in community composition across habitats, as indicated by alpha and beta diversity metrics (P < 0.05). These findings provide a critical baseline for understanding vector dynamics in swine production systems and highlight the need for sustained mosquito surveillance to inform arbovirus risk mitigation strategies.