Synchrony of globally invasive Aedes spp. immature mosquitoes along an urban altitudinal gradient in their native range

Abstract

Mosquito-borne infections often have concerted peaks, or are synchronous, across landscapes. This phenomenon might be driven by vector responses to similar environmental conditions that synchronize their abundance. While adult mosquito populations can be synchronous over spatial scales ranging from a few meters to a few kilometers, little to nothing is known about immature mosquito synchrony, including its relationship with mosquito colonization and persistence in larval habitats. Here, we present results from a 2-yearlong synchrony study in co-occurring populations of Aedes (Stegomyia) albopictus (Skuse), Aedes (Stegomyia) flavopictus Yamada and Aedes (Finlaya) japonicus japonicus (Theobald), three invasive mosquito species, along an urban altitudinal gradient in Japan. We found that Ae. albopictus was asynchronous while Ae. flavopictus and Ae. j. japonicus had synchrony that, respectively, tracked geographic and altitudinal patterns of temperature correlation. Spatially, Ae. albopictus was more persistent at hotter locations near urban land use, while Ae. j. japonicus and Ae. flavopictus increasingly persisted farther away from urban land. Temporally, Ae. albopicus and Ae. flavopictus decreased the proportion of colonized habitats following variable rainfall, while Ae. j. japonicus increased with vegetation growth and leptokurtic temperatures. Our results support the hypothesis that immature mosquito synchrony is autonomous from dispersal and driven by common environmental conditions.

Keywords: Land use; Moran effect; NDVI; Schmalhausen's law; Time series analysis.