Continued range expansion of Aedes albopictus (Diptera: Culicidae) in Iowa, United States.

The mosquito Aedes albopictus (Skuse) (Diptera: Culicidae) serves as a competent vector of several arboviruses, including dengue, chikungunya, and Zika viruses, and is highly invasive, spreading to every continent except Antarctica. With the emergence of Zika virus in the Americas in 2015 and 2016, targeted surveillance efforts for invasive Aedes species were initiated in Iowa, documenting the detection and establishment of Ae. albopictus in 3 Iowa counties over a 5-yer period (2016 to 2020). Herein, we provide an update on the abundance of Ae. albopictus based on our continued surveillance efforts over the past 5 yr (2021 to 2025) across 19 Iowa counties, further documenting its spatial distribution and temporal abundance in the state to at least 11 counties. Highlighting trapping efforts in 2 Iowa counties with previous or recently detected populations of Ae. albopictus, we provide a detailed examination of their increased detections in these locations, offering new insight into their continued spread in the state to locations that were previously negative for Ae. albopictus. Together, these data provide further evidence for the continuing range expansion of Ae. albopictus in Iowa, which serves as its current northern range in the Upper Midwest. These findings have broad implications for the future spread of this invasive mosquito species in the United States and its potential impacts on public health.