Olivier Glaizot

The impacts of landscape anthropization on mosquito abundance and diversity are already well studied, but the underlying ecological factors behind these effects are still poorly understood. One such underlying ecological factor may be related to the loss of amphibians in human‐modified landscapes, providing ideal habitats for several mosquito species. In this study, we conducted a mosquito and amphibian larvae survey in 77 ponds along a gradient of landscape anthropization in western Switzerland. We used structural equation models to investigate the direct and indirect effects of building footprints and several local pond parameters on mosquito abundance and composition through amphibian abundance. We highlighted that landscape anthropization increases the presence probability of mosquito larvae and the proportion of Culex pipiens in mosquito communities. Our results also suggested that one of the ecological mechanisms underlying these effects is a reduction in amphibian abundance, limiting competition and predation experienced by mosquitoes in human‐modified landscapes. In addition, we showed that several local pond characteristics prevent the presence and abundance of mosquito larvae. Indeed, deep ponds, which promote amphibian abundance, limit the probability of larval mosquito presence, and large and old ponds have a lower larval mosquito abundance. Amphibians appear to be effective control agents of natural mosquito populations. Therefore, the development of measures to protect amphibians in human‐modified landscapes could help to reduce both mosquito‐related nuisances and the risk of emergence of vector‐borne diseases in humans and wildlife.

In recent decades, the emergence and resurgence of vector‐borne diseases have been well documented worldwide, especially in tropical regions where protection and defense tools for human populations are still very limited. In this context, the dynamics of pathogens are influenced by landscape anthropization (i.e., urbanization, deforestation, and agricultural development), and one of the mechanisms through which this occurs is a change in the abundance and/or diversity of the vectors. An increasing number of empirical studies have described heterogeneous effects of landscape anthropization on vector communities; therefore, it is difficult to have an overall picture of these effects on a global scale. Here, we performed a meta‐analysis to quantify the impacts of landscape anthropization on a global scale on the presence/abundance and diversity of mosquitoes, the most important arthropods affecting human health. We obtained 338 effect sizes on 132 mosquito species, compiled from 107 studies in 52 countries that covered almost every part of the world. The results of the meta‐analysis showed an overall decline of mosquito presence/abundance and diversity in response to urbanization, deforestation, and agricultural development, except for a few mosquito species that have been able to exploit landscape anthropization well. Our results highlighted that these few favored mosquito species are those of global concern. They, thus, provide a better understanding of the overall effect of landscape anthropization on vector communities and, more importantly, suggest a greater risk of emergence and transmission of vector‐borne diseases in human‐modified landscapes.