Oxitec has created a breed of mosquito whose offspring don’t survive to adulthood in an effort to eradicate mosquito-borne illness.

A controversial plan by U.K. biotechnology firm Oxitec could eliminate a virus that causes 2.3 million infections and 25,000 deaths per year worldwide, but at the expense of driving an entire species to extinction.

Oxitec scientists have engineered flightless female and sterile male Aedes aegypti mosquitoes that either cannot reproduce or whose offspring die before reaching maturity.

“After an Oxitec mosquito has successfully mated with a wild female, any offspring that result will not survive to adulthood, so the mosquito population declines,” according to the company’s website. “By applying the Oxitec Control Programme to an area, the mosquito population in that area can be dramatically reduced or eliminated.”

Their goal is to stop the transmission of dengue fever, which according to the World Health Organization , has spread rapidly in recent decades, putting nearly half of the world’s population at risk for infection. It is spread from person to person almost exclusively by Aedes aegypti.

Dengue typically causes flu-like symptoms and joint pain, but can rarely develop into dengue hemorrhagic fever, or severe dengue, which causes tissue bleeding and sometimes death.

As of now, there is no cure—or even a specific treatment—for dengue. All affected populations can do is spray insecticide and erect nets to keep the mosquitoes at bay.

Oxitec’s genetically modified organisms, or GMOs, may seem like the perfect solution—kill them before they kill us—but public reaction to the mosquitoes has been decidedly mixed.

As with genetically modified food crops, many worry about the unknown consequences of disrupting natural ecosystems and playing favorites with living things.