Various studies have shown that the prevalence of mosquito borne diseases such as malaria and dengue fever is correlated to deforestation and urbanization. Some factors that can explain such a correlation are, for example, changes in micro-climatic conditions that come with such changes in the landscape but also the availability of breeding habitats for mosquitoes. We wondered if effects on the landscape scale would also affect predator prey interactions. Different species may be affected by landscapes in different ways and it is therefore likely that a correlation between such changes and the abundance of vector mosquitoes could result from changes in predator-prey interactions.
Hence, we conducted a field experiment in which we placed water-filled containers in trees along a gradient of forest and urban habitats and monitored the dengue vectors and predators that colonized these containers. We found that aquatic predators more quickly colonized containers in landscapes that contained more green spaces (think of forests but also urban parks). In addition, the distance to large aquatic habitats also had a major effect on the colonization rate of predators. In containers that were colonized with predators the mosquito densities were much lower.
We can conclude that in urban areas mosquitoes prevail due to a decreased colonization rate of predators, which may be another underlaying factor that helps explaining the relationship between deforestation, urbanization and dengue fever.
You can read more about this study here.