The CDC’s website, where the agency in question tracks the regions where one might find Aedes aegypti. Aedes aegypti is a species of mosquito that’s known to extent diseases like chikungunya, Zika, and dengue — which can lead to epidemics.

Nearly all of California is included in this map, and it’s led the government to board on a bold and potentially risky plan — sending genetically engineered mosquitos out into the wild to diminish the population of Aedes aegypti.

An article in the Los Angeles Times explores the ideas at the heart of the plan, as well as the explanations why some residents are concerned about its significances. The mosquitos were designed by the company Oxitec; essentially, when the males mate with female Aedes aegypti, the resulting female offspring die. Given the speed at which mosquitos reproduce, this can — in theory — have a considerable effect on plummeting the mosquito population.

The EPA is in favor of this experiment going onward in California’s Tulare County. California’s state government still needs to approve it, however — and given that this technology is in its early days, there are plenty of concerns surrounding what could potentially go wrong.

If this project does go ahead and is fruitful, these genetically engineered mosquitos could be deployed to more regions around the world where mosquitos spread disease — but that’s still a big if.