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Abstract BackgroundUrbanization can influence disease vectors by altering larval habitat, microclimates, and host abundance. The global increase in urbanization, especially in Africa, is likely to alter vector abundance and pathogen transmission. We investigated the effect of urbanization and weather on the abundance of two mosquitoes,Aedes aegyptiandAedes albopictus, and infection with dengue, chikungunya, and Zika viruses at 63 sites in six cities spanning a 900-km latitudinal range in Cameroon, Central Africa. MethodsWe used human landing catches and backpack-mounted aspirators to sample mosquitoes and collected larval habitat, host availability, and weather (temperature, precipitation, humidity) data for each site in each city. We analyzed land use and land cover information and satellite photos at varying radii around sites (100 m to 2 km) to quantify the extent of urbanization and the number of structures around each site. We used a continuous urbanization index (UI; range 0–100) that increased with impermeable surface and decreased with forest cover. ResultsUrbanization increased larval habitat, human host availability, andAe. aegyptimosquito abundance.Aedes aegyptiabundance increased 1.7% (95% CI 0.69–2.7%) with each 1 unit increase in the urbanization index in all six cities (Douala, Kribi, Yaounde, Ngaoundere, Garoua, and Maroua) with a 5.4-fold increase from UI = 0 to UI = 100, and also increased with rainfall. In contrast,Ae. albopictusabundance increased with urbanization in one city, but showed no influence of urbanization in two other cites. Across three cities,Ae. albopictusabundance increased with rainfall, temperature, and humidity. Finally, we did not detect Zika, dengue, or chikungunya viruses in any specimens, and found weak evidence of interspecific competition in analyses of adult population growth rates. ConclusionsThese results show that urbanization consistently increasesAe. aegyptiabundance across a broad range of habitats in Central Africa, while effects onAe. albopictuswere more variable and the abundance of both species were influenced by rainfall. Future urbanization of Africa will likely increaseAe. aegyptiabundance, and climate change will likely alter abundance of both species through changes in precipitation and temperature. Graphical Abstract 

Abstract Laboratory and field-based studies of the invasive mosquito Aedes albopictus demonstrate its competency to transmit over twenty different pathogens linked to a broad range of vertebrate hosts. The vectorial capacity of Ae. albopictus to transmit these pathogens remains unclear, partly due to knowledge gaps regarding its feeding behavior. Blood meal analyses from field-captured specimens have shown vastly different feeding patterns, with a wide range of anthropophagy (human feeding) and host diversity. To address this knowledge gap, we asked whether differences in innate host preference may drive observed variation in Ae. albopictus feeding patterns in nature. Low generation colonies (F2–F4) were established with field-collected mosquitoes from three populations with high reported anthropophagy (Thailand, Cameroon, and Florida, USA) and three populations in the United States with low reported anthropophagy (New York, Maryland, and Virginia). The preference of these Ae. albopictus colonies for human versus non-human animal odor was assessed in a dual-port olfactometer along with control Ae. aegypti colonies already known to show divergent behavior in this assay. All Ae. albopictus colonies were less likely (p < 0.05) to choose the human-baited port than the anthropophilic Ae. aegypti control, instead behaving similarly to zoophilic Ae. aegypti . Our results suggest that variation in reported Ae. albopictus feeding patterns are not driven by differences in innate host preference, but may result from differences in host availability. This work is the first to compare Ae. albopictus and Ae. aegypti host preference directly and provides insight into differential vectorial capacity and human feeding risk.