Aedes mosquitoes are limited to where they can live by multiple factors, predominantly temperature and rainfall. The insects need high temperatures, but also need rainfall as they lay their eggs in water. These factors help to limit the habitable zone of Aedes largely to the topics. However, with global warning, the regions in which the mosquitoes can survive and spread is increasing, causing concern about the viral diseases they can transmit.
The study, which was published in the journal eLife, aimed to establish models to predict the global regions that Aedes egypti and albopictus could live. The models were based on real world data gathered by capturing mosquitoes across the globe. In total, 19,930 A. egypti and 22,137 A. albopictus mosquitoes were captured. Most of these were captured in Asia, 60% of the A. egypti and 75% of the A. albopictus captures. The Americas came in a comfortable second for the highest proportion of captures. This suggests that most of the mosquitoes currently reside in tropical parts of Asia and the Americas. Building on this knowledge, and factoring in climactic conditions that impact mosquito survival, models were generated to predict potential areas that the mosquitos can live.
Using these models, we now have more information about areas that could be at risk of the viral diseases carried by the mosquitoes. For instance, Mexico is predicted to have ideal conditions for the two mosquito species, even though none were captured there during the course of the study. In Europe, captures suggested that Greece and Italy have an increasing presence of the mosquitoes, and that while none were captured there, Spain, Portugal and much of south-eastern Europe have good conditions for spread.