Displacement of Aedes albopictus by Aedes aegypti in Gainesville, Florida.

Aedes aegypti and Ae. albopictus are invasive mosquitoes, capable of vectoring arboviruses such as dengue, chikungunya, yellow fever, and Zika. Recent shifts in spatial distribution indicate there is a resurgence of Ae. aegypti in certain regions of Florida. After a 26-year absence, Ae. aegypti larvae were collected in a downtown neighborhood in Gainesville, Florida, in November 2019. Subsequent surveys confirmed that Ae. albopictus was completely displaced by Ae. aegypti in this neighborhood, whereas Ae. albopictus and Ae. aegypti coexisted around this community focus, and Ae. albopictus alone has been found elsewhere in the city and county since the 1990s. Field surveys revealed that Ae. aegypti is resurging in the downtown area of Gainesville and is actively dispersing to adjacent neighborhoods. Thus, Ae. aegypti could potentially replace Ae. albopictus across more of urban Gainesville in north-central Florida, as reported recently in coastal cities of northeastern Florida.

Efficacy of Residual Pesticide-Treated Plant Saucers Against Aedes albopictus Larvae Under Semi-Field and Field Conditions.

Plant saucers are ubiquitous, outdoor water-holding receptacles and are one of the most productive domestic mosquito habitats in the urban environment. Two kinds of commonly used plant saucers, clay and plastic, were manually treated with 3 residual insecticides, bifenthrin (Talstar® Professional), lambda-cyhalothrin (Lambda 9.7 CS), and tau-fluvalinate (Mavrik® Perimeter), at their maximum rates to assess their residual efficacy against Aedes albopictus larvae under semi-field and field conditions. Both clay and plastic saucers treated with bifenthrin and lambda-cyhalothrin provided weeks of control of 3rd instars of Ae. albopictus, whereas tau-fluvalinate provided only 1 day of control. Results from this study show that bifenthrin and lambda-cyhalothrin can provide good control of Ae. albopictus larvae for a considerable period of time and have great potential with regard to container mosquito management in the future.