Aedes albopictus Populations and Larval Habitat Characteristics across the Landscape: Significant Differences Exist between Urban and Rural Land Use Types

Simple Summary More than 50% of the global population now resides in cities. In addition to large human populations, some cities support large populations of vectors, such as mosquitoes. Consequently, we have seen a resurgence in urban outbreaks of mosquito borne diseases, e.g., West Nile and dengue fever, in the last 60 years. The Asian Tiger mosquito, Aedes albopictus, is an ecologically flexible species that has colonized every continent, except Antarctica, in recent decades. In this paper, we tested the prediction that A. albopictus is more abundant in human-dominated, urban, and suburban areas compared to rural areas in a temperate US city. We collected data on mosquito abundance and other aspects of the environment important for mosquitoes and that also may vary by land use type. As predicted, we found higher densities of A. albopictus in urban and suburban areas compared to rural ones. We also found few other mosquito species, higher average temperatures, lower nitrogen levels in aquatic larval habitats, and faster water evaporation in some sample weeks. We conclude that this species is thriving in human-dominated areas in this metropolitan region, and its success may be partially due to the environmental characteristic of this habitat type. One of the most profound recent global changes has been the proliferation of urban metropolitan areas. A consequence of urbanization is a reduction in abundance, or diversity, of wildlife. One exception, is the proliferation of vectors of disease; recent years have seen the emergence and resurgence of diseases vectored by species closely associated with humans. Aedes albopictus, a mosquito with a near global range and broad ecological niche, has been described as an urban, suburban, or rural vector, or a forest edge species depending on local conditions. We tested the hypothesis that abundance and phenological patterns of this species vary among different land use types in a temperate city because of the variation in the biotic and abiotic conditions characteristic of those habitat types. A. albopictus populations in urban and suburban areas were an order of magnitude larger than in rural areas and were detected several weeks earlier in the season. Additionally, we found fewer overall mosquito species, higher temperatures, lower nitrogen, higher pH, and faster water evaporation in larval habitats in urban vs. rural areas. By understanding the ecological differences that facilitate a species in one habitat and not another, we can potentially exploit those differences for targeted control.

Automated summary

With more than 50% of the global population now residing in cities, there has been a resurgence in urban outbreaks of mosquito-borne diseases such as West Nile and dengue fever. The Asian Tiger mosquito has been found to be more abundant in urban and suburban areas compared to rural areas in a temperate US city, with factors like temperature, nitrogen levels, and water evaporation playing a role in its success in human-dominated habitats.