Bees across South Carolina are dying by the truckload as the state attempts to control mosquitoes carrying the Zika virus.

The cause of the honeybee die-off is likely from the spraying of pesticides targeting the Aedes albopictus andAedes aegypti species of mosquito, which carry the Zika virus.

zika virus

Southern states like Florida and South Carolina are spraying pesticides from trucks and airplanes in mosquito-heavy areas in an effort to control the virus that can cause serious birth deformities if transmitted to a pregnant woman, either by the mosquito itself or through sexual contact.

However, as the Washington Post reported, the spraying is having a devastating side effect on local bee populations.

At Flowertown Bee Farm and Supplies, based in Summerville, South Carolina, roughly 2.5 million bees in 46 hives died simultaneously on Sunday.

Bee farmers suspect the culprit is Naled, the pesticide being sprayed from the air in Dorchester County, South Carolina. In an interview with the Associated Press, Flowerton Bee Farm and Supplies co-owner Juanita Stanleydescribed the scene, saying her farm “looks like it’s been nuked.”

The danger of Naled to local bee populations has been previously documented by Cornell University researchers as early as 23 years ago, who wrote “Naled is highly toxic to bees” in the study.

The mass killing of bees can cause potentially irreparable harm to the food supply. As University of Minnesota entomology professor Marla Spivak wrote for CNN, 71 of the 100 crops that make up 90 percent of the global food supply depend on bees to survive.

Counties fighting Zika usually spray pesticides at night, when bees are sleeping in their hives and not pollenating.

However, Dorchester County sprayed Naled between 6:30 and 8:30 on a particularly hot day, when bees tend to exit the hive to cool off in a cluster called a “beard.”

Bee farmers say that particular spraying is what killed off their bee supply.

“They passed right over the trees three times,” Stanley told local media.