Scientists are raising millions and millions of parasite-infected mosquitos, cared for by robots. They also plan to release them into major population centers, too — but don’t worry — it’s for your own good.

These millions of mosquitos belong to Verily Life Sciences, one of Google’s sibling companies under the Alphabet umbrella. The subsidiary is on a mission to eliminate one of the most hated pests on the planet: mosquitos. So to accomplish their mission, the group partnered with the Consolidated Mosquito Abatement District and MosquitoMate. In a study called Debug Fresno, the team tried to show they they could effectively target just one of the 3,500 species of mosquitos that exist, Aedes aegypti.

malaria death map 2012
Deaths per million, calculated by the WHO in 2012.

Aedes aegypti, aka the yellow fever mosquito, is considered often the mother load for terrifying diseases, carrying maladies like Zika virus, chikungunya, and dengue. Though the species is well-studied, it’s incredibly difficult to mitigate, since it doesn’t even require an open body of water to reproduce: any nook or cranny will do. Their one redemptive trait, as far as humans are concerned, is that they don’t fly as far as other species of mosquitos. Their particular combination of geographic concentration and deadliness has made them an attractive target for researchers, because they’re both comparably easy to study while offering the opportunity to make an outsize impact.

Fighting Mosquitos With Mosquitos

Verily’s study hinges on a tiny bacterium called Wolbachia. The parasite’s superpower — hacking the reproductive systems of species, rendering them sterile — means that when Wolbachia-ridden mosquitos mate with wild mosquitos, the eggs produced by that union are a dead end. Generation by generation, this adds up to a diminished, if not eliminated, mosquito population. With the help of robot nannies raising their bug army, researchers decided to breed and infect male mosquitos for this purpose, since only the females hunt for human blood.

debug fresno van
How many mosquitos are inside that van?

Scientists have eyed Wolbachia for years, making Verily Life Sciences one of many companies refining the Sterile Insect Technique (SIT), which dates back to the 1950s. The technique is far from perfected: Some studies found that certain combinations of Wolbachia and Plasmodium, the genus of organisms that includes malaria parasites, actually heightens other species of mosquitos’ ability to spread the disease instead.

Nobody wants a plot twist when the apocalyptic hum of millions of mosquitos descending upon California arrives in earnest.

Is This the End of Aedes aegypti?

Despite some setbacks in the field of SIT, Verily Life Sciences has shown the technique can work. In 2017, they released their first swarm in Fresno County, reducing the number of biting females by 68 percent, compared to other areas. In 2018, after expanding their hit zone to three additional neighborhoods and letting out their home-bred bugs earlier in the season, they netted a 95 percent reduction of biting females in the treated area.

The research community isn’t certain that slapping those suckers to the ground is a clear win. Verily explains on their website that eliminating the bloodthirsty bugs would simply restore the natural order, since they’re an invasive species. They don’t pollinate crops or make up a significant food source for animals, and the Wolbachia technique leaves other species of bugs like ladybugs or honeybees safe — something that traditional insect repellants often fail to do.

Critics suggest that Aedes aegypti would be soon replaced by another vector in the disease chain, or that the effects of eliminating an entire species on the ecosystem are just too unpredictable.

raising mosquitos
The study involves sorting male and female mosquitos, a process Verily Life Sciences hopes to expedite in the future.

But following Verily’s smashing success, the company plans to move forward with the study, though it’s still refining the volume of “good bugs” to release while keeping an eye on future aspirations to scale up.

So if you see a white van unleashing a swarm of mosquitos near you, it might not be the apocalypse, or an exterminator’s biggest payday. It might be the sound of the 3,500 species of mosquitos that could be circling your neighborhood going down to 3,499.

Correction: A previous version of the story erroneously reported that Aedes aegypti transmits malaria in addition to other diseases. It has been updated with additional comment Verily Life Sciences.