Interactive effects of land use, temperature, and predators determine native and invasive mosquito distributions

Abstract

Abstract Land‐use and climate change could alter the distribution of both native and exotic mosquitoes by changing abiotic and biotic characteristics of freshwater habitats. We initially studied the influence of land use on standing water habitats, and the subsequent effects on native and exotic mosquito and mosquito‐predator presence. Associated with abiotic habitat characteristics, mosquito‐predator richness was highest in aquatic habitats of natural land uses (forest and grassland), and lowest in human‐modified land uses (pastoral and urban), and the opposite relationship was true for mosquito presence. Based on the outcome of the field survey we investigated the potential effects of climate‐induced habitat warming and drying on interactions between invasive Aedes notoscriptus and native Culex pervigilans mosquitoes and native invertebrate predators affected by the land‐use gradient. Predator presence, which is directly affected by both climate and land‐use change, influenced both mosquito survivorship and behaviour. We found predation rates increased with temperature, but the magnitude of changes depended on both predator and prey identity. In general, higher temperatures increased mosquito pupation rates, but also made mosquitoes more susceptible to predation. Although invasive A. notoscriptus were more susceptible to predation, increased temperature resulted in shorter life cycles, thereby reducing the net effect of increased predation caused by higher temperatures. Overall, our results suggest interactions between temperature, land use and predator identity will be important in determining mosquito distributions, and will likely differ between mosquito species. Such interactions and species‐specific responses will be particularly important if environmental changes facilitate range expansion of invasive mosquito species that are vectors for disease.