Clemson University scientists and South Carolina officials are investigating the possible deaths of millions of bees last month after the aerial spraying of an anti-Zika pesticide.
The mosquito-killing product containing the active ingredient Naled was sprayed on Aug. 28, in the Summerville region of Dorchester County. The area is home to several residents who contracted the Zika virus while traveling outside the state.
Meanwhile, neighboring Charleston County, where eight travel-related Zika cases have been reported, on Wednesday began spraying unpopulated areas with an organic product designed to kill mosquito larvae in standing water prior to hatching. That program will continue through Sept. 12.
Dr. Mike Weyman, deputy director of Clemson University Regulatory Services, told AMI Newswire that soil and bee samples were taken at the Flowertown Bee Farm in Summerville, where 45 beehives were destroyed on the day when Dorchester County sprayed the area to control adult mosquitoes. A single bee colony typically contains about 50,000 bees, so two million bees might have been killed.
“It’s unfortunate that this happened,” Weyman said, “but we can’t lose sight of the fact that this is a public health crisis."
As of Wednesday, the South Carolina Department of Health and Environmental Control (DHEC) reported that the state had confirmed 46 travel-related cases of the Zika virus, including one case that was transmitted sexually. The virus, which is spread by the Aedes mosquito species, can be passed from a pregnant woman to her unborn child, who is then at risk of birth defects, reports the federal Centers for Disease Control.
Weyman said that Naled, the active ingredient in a commercial insecticide called Trumpet, does not pose a threat to people when applied properly. Exposure can harm honey bees, however, and the Environmental Protection Agency reports that applications of the product between dusk and dawn reduce the risks to bees, which tend not to forage during those hours.
“It’s an extremely valuable tool in the toolbox for treating or suppressing adult mosquitoes,” he said.
Weyman emphasized that the pesticide was applied in Summerville in response to travel-related Zika cases. Mosquito abatement officials attempted to reduce risks to public health by working to suppress adult mosquitoes around the areas where the infected residents live, he said.
This was required to keep local mosquitoes from taking blood from any of the infected people. If that had happened, it could have led to future vector-caused infections in the county, Weyman said.
“DHEC looked at this as a clear and present public health threat,” he said.
Officials are hoping to wrap up the investigation by the latter part of next week and will examine whether there were any violations of label instructions on the use of the pesticide, Weyman said.
“This is a very intricate investigation, turning over every rock to determine the outcome,” he said.
Though Weyman characterized the bee deaths at Flowertown Bee Farm as “catastrophic,” he also said that possible effects on agriculture would not likely be widespread. Though bees can forage and pollinate over distances of two to three miles, the main purpose of the bees at Flowertown was to collect honey.
Although Flowertown co-owner Juanita Stanley was unavailable for comment, an effort has been launched at the website Gofundme.com to help raise money to compensate for the company’s losses. As of Wednesday, about $7,400 had been raised.
“Due to the unfortunate application of the aerial spraying of an insecticide called Naled, my bees have taken a devastating blow, causing me to refocus my efforts on informing and education,” a note on the website said. “This must not happen to anyone again!”
Dorchester County officials urged beekeepers to register with the county in order to receive notifications of future aerial spraying plans. “No additional aerial spraying flights for mosquitoes are scheduled at this time,” county officials stated in a news release. “Prior to any additional aerial spraying, notification will be sent out three to five days in advance.”
The county reported that prior to the Aug. 28 spraying, notices were sent to media outlets in the region as well as via social media. A news release was also published on the county website about 48 hours prior to the spraying.
County governments are ultimately responsible for decisions to employ aerial spraying to combat the Zika virus, the Carolina Farm Stewardship Association said in an email to AMI. The association, which educates residents of the Carolinas about local, organic foods, urged people who keep honey bees or are involved in organic agriculture to contact their county administrator’s office in order to have their properties excluded from aerial spraying.
The spraying of mosquito larvae in Charleston County is taking place between 6 a.m. and 9 p.m., according to a county news release. In the past, the county has also sprayed using the Trumpet pesticide to kill adult mosquitoes, and it gives the 90 beekeepers in its database at least 24 hours notice prior to aerial spraying, officials said.