How are environmental changes, loss of biodiversity, and the spread of pathogens connected? The answer is a puzzle. Scientists from Charité – Universitätsmedizin Berlin in cooperation with the Leibniz-IZW have now described one piece of that puzzle in a study on the effects of rainforest clearing on mosquitoes and the viruses they carry the journal “eLife”. They show that the destruction of tropical rainforests harms the diversity of mosquito species. At the same time, more resilient species of mosquitoes become more prevalent – which also means the viruses they carry are more abundant. If there are many individuals of a given species, those viruses can spread quickly.