Reports out of South Carolina have indicated that when officials approved the spraying of local farmlands with insecticide to prevent the spread of Zika-carrying mosquitos, it accidentally wiped out millions of bees too.

The insecticide in question, called Naled, is known to be “highly toxic” to bees, and these vital pollinators appear to be the latest collateral damage in the fight against Zika.

In response to the ensuing outcry from local farmers after last Sunday’s bout of aerial spraying in Dorchester County, the local administrator’s office announcedthat the state health department had reported four travel-related cases of Zika virus in the Summerville area of Dorchester County on Friday 26 August.

While the health department reported that no one has been infected from a local mosquito bite to date, Dorchester County officials justified the accidental bee cull on the grounds that the mosquito population remained a threat.

“Dorchester County is concerned about the safety of its citizens,” a statement from the County Administrator’s Office reads. “This includes protecting citizens from insect bites from pests such as mosquitoes that carry viruses including West Nile and Zika.”

The spraying commenced at 6:30am last Sunday morning, and the effects on bees were reportedly instant.

“Stressed insects tried to flee their nests, only to surrender in little clumps at hive entrances,” Ben Guarino reports for The Washington Post. “The pattern matched acute pesticide poisoning. By one estimate, at a single apiary – Flowertown Bee Farm and Supply, in Summerville – 46 hives died on the spot, totalling about 2.5 million bees.”

The decision to conduct aerial spraying with Naled – something that’s never been done in South Carolina before – is of course highly controversial, but what’s perhaps even more contentious is the fact that local officials claim to have warned farmers ahead of Sunday.