Evaluating vector mosquito occurrence in residential rain barrels in central Illinois

Several species of vector mosquitoes (e.g., Culex pipiens (Linnaeus, 1758), Aedes albopictus (Skuse, 1895)) complete juvenile development in artificial containers. Rain barrels are green infrastructure tools used to conserve rainwater for outdoor use, though they may also serve as a source of mosquito habitat in residential neighborhoods. To identify rain barrel features, maintenance habits, and other conditions associated with the presence of juvenile mosquitoes (i.e., month), we conducted periodic inspections of rain barrels at 53 households in central Illinois, USA, between June and September 2016. Additionally, we administered a questionnaire to the household study participants. In the first month of the study, a diversity of mosquito species was detected in household rain barrels, but for July-September, juveniles of Ae. albopictus were predominant. More than half of the inspected households contained at least one mosquito-positive rain barrel within the study period. Using stepwise model selection, the strongest predictors of whether or not mosquito juveniles were detected in rain barrels were the use of a preventative measure (e.g., Bti, chlorine, goldfish), the presence of a mesh covering on the lid of the barrel, and the month of the year. Additionally, the participant questionnaire revealed that the majority of respondents were aware of immediate elimination methods, but few were aware of the need for long-term preventative maintenance of rain barrels against larval mosquito colonization. These findings provide valuable insight into best practices for mosquito prevention in green infrastructure and highlight the importance of proper maintenance and education to minimize juvenile mosquito habitat.