Aedes albopictus and Culex pipiens mosquitoes: Competition across socioeconomic gradients

Non-native mosquitoes Aedes albopictus and Culex pipiens are two of the most abundant urban mosquito species in the eastern United States and can vector numerous arboviruses. Previous research shows that adult mosquitoes are larger, more abundant, and have higher infection rates in low-income Baltimore, MD and Washington, DC neighborhoods, creating a disproportionate and unjust risk of disease for residents. The abundance, distribution, and vectorial capacity of A. albopictus and C. pipiens are mostly determined by developmental ecology in water-filled container habitats, which usually includes strong resource competition for allochthonous organic detritus and can be affected by temperature. Field observations revealed distinct plant communities and different microclimates along socioeconomic gradients, with a greater frequency of non-native plants and higher mean temperatures in low-income neighborhoods. Based on these results, we conducted two density-dependent mosquito competition trials. The first tested the effects of three detrital resource bases on mosquito survival and development time: a non-native plant mix characteristic of low-income blocks (Ailanthus altissima, Paulownia tomentosa), a native plant mix characteristic of high-income blocks (Acer rubrum, Ulmus americana), and a combination of native and non-native plants found with similar frequency across income brackets (Juglans nigra, Morus alba). The second set of trials tested the effects of four temperature regimes: low constant, low fluctuating, high constant, and high fluctuating. We found that conditions characteristic of low-income neighborhoods promoted higher rates of survival and faster development, and also alleviated larval competition. Understanding the ecological mechanisms underpinning mosquito ecology can help us better address associated disease risks.