Social and ecological risk factors for mosquito production in residential neighborhoods

Mosquitoes (Diptera: Culicidae) transmit many pathogens that affect human and wildlife health, including West Nile, Zika, dengue, and chikungunya viruses. Since vaccines are not currently available for many of these pathogens, control of the vectors is the most effective method to reduce disease risk. In the United States, the mosquitoes of greatest disease concern are container-breeding mosquito species. Females of these species oviposit in natural and man-made container habitats, where the resulting larvae develop and compete for nutritional resources. In human-dominated landscapes, mosquito abundance and species composition are determined by the interaction of ecological and social factors. This dissertation examines both ecological and social factors that affect mosquito populations to elucidate which factors drive mosquito production in residential neighborhoods in the midwestern United States. In Chapter 1, I provide background information about social and ecological factors that may affect container-breeding mosquitoes in residential neighborhoods. In Chapter 2, I examined the distribution and abundance of various container types and their productivity for mosquito juveniles at 83 residential properties in nine neighborhoods. The nine neighborhoods were stratified across three levels of socioeconomic status (SES) and three levels of canopy cover. Large container types harbored the greatest number of mosquito juveniles. While low SES neighborhoods had the lowest frequency of containers, the containers in low SES neighborhoods were most likely to be positive for mosquito juveniles. Additionally, I conducted a knowledge, attitudes, and practices (KAP) questionnaire in the same neighborhoods to determine residents’ knowledge about mosquito ecology, attitudes towards mosquitoes, and self-reported mosquito control practices. Results from the KAP show that residents in low SES neighborhoods and younger residents are the least knowledgeable about mosquito ecology, while residents in high SES neighborhoods and older residents were the most likely to report control practices. In Chapter 3, I conducted an oviposition choice assay to determine if females of different mosquito species exhibit preference for certain commonly-found man-made containers. A garbage can, flower pot, and flower pot saucer were placed together at 8 residential field sites for 40 days. The garbage can was removed at half the field sites at day 20 to examine how removal of the largest, most productive habitat affected oviposition choice. Culex spp. preferentially oviposited in the garbage can, and when removed, the total number of egg rafts laid decreased. Aedes spp. preferentially oviposited in garbage can and flower pots, but there was no significant difference between the total numbers of eggs laid when the garbage can was removed compared to when the garbage can was present. In Chapter 4, I explored a potential mosquito control strategy for clogged rain gutters, an often overlooked but productive container habitat, by using experimental rain gutters to compare two gutter guard treatments to an unmodified control. Results showed that the presence of gutter guards increases mosquito production in clogged gutters, so gutter guards are not an effective control strategy. Collectively, these studies provide insight into ecological and social factors contributing to mosquito production in residential neighborhoods, and can be used to develop more effective integrated mosquito control techniques in residential settings