Wolbachia mosquitoes are one of the best tools against dengue and Zika.

Wolbachia-infected mosquitoes help control dengue and Zika by making the mosquitoes themselves less capable of transmitting the viruses, and in some cases, by suppressing the mosquito population entirely.

Here’s how it works: Wolbachia is a naturally occurring bacterium that infects many insects, but not the Aedes aegypti mosquito — the main vector for dengue and Zika. Scientists inject it into mosquito eggs in the lab. When those mosquitoes