A laboratory in Valencia, Spain, is working to stop the spread of dengue fever and other diseases by breeding and sterilizing thousands of tiger mosquitoes, a species that is growing more common due to climate change. As warmer temperatures create perfect conditions for these mosquitoes to grow and spread across Europe, the regional government-funded Biological Pest Control Centre in Valencia started a large sterilization program. Every week, around 45,000 male mosquitoes are sterilized using an electron accelerator and then released into the environment. The plan is for these sterilized males to mate with females, which are the ones that bite humans and spread diseases. By stopping the females from reproducing, the program aims to slowly reduce the mosquito population and control the spread of diseases carried by mosquitoes.

This European project, led by the laboratory with experience in controlling fruit flies, is essential as the threat of diseases like dengue, Zika, and chikungunya rises. Locally sourced mosquitoes are used in the program, where scientists use special machines to separate female pupae from males before sterilizing the males with radiation. The European Centre for Disease Prevention and Control has reported an increase in imported dengue cases and local outbreaks of diseases like the West Nile virus. The tiger mosquito, Aedes albopictus, is now establishing populations in 13 European countries, including Spain. The World Health Organization reported that global dengue cases have increased eightfold since 2000, reaching 4.2 million in 2022, a trend linked to climate change’s impact on mosquito populations.