While gray caterpillars covering trees throughout the South look creepy as hell, they are doing plenty of harm to local ecosystems.
Florida’s Department of Environmental Protection released a video on Thursday urging residents to treat areas with the insects, which have taken over the state this year after building their fatness by ingesting harmful substances such as antifreeze and nicotine.
“Most people just ignore them, but they are a real threat,” Frances Gulland, an environmental scientist with the department, said in the video.
Numerous reports have made the rounds online in recent weeks suggesting the huge larvae of the Mexican brown tree moth have been up to damaging their hosts in recent months. Business Insider reported that a barbed-wire fence in Henderson, North Carolina, was destroyed by one. Some nature sites, including the Nantahala National Forest, posted photos of the tail of the larvae splattered on a tree stump.
Some reports of infected trees contain the toxin 1080. Found naturally in many forests in the Pacific Northwest, the chemical can be deadly to bats, cows and even birds, according to the Natural Resources Defense Council.
The Mexican brown tree moth’s egg masses have been found in Georgia, Alabama, North Carolina, South Carolina and Virginia. Gulland said the insects were first observed in Florida in 2015, and that early this year they covered some 1.5 million trees, an increase from the 1.2 million they were found on in 2015.
Dr. Ed Fricke, a botanical biologist with the University of Florida, said in an interview with “Florida Today” that this year’s unusually large population is due to a combination of warmer temperatures and new, harder habitats.
The insect’s larva lay their eggs on the trunk of trees, then remain active for months to take root under the bark, according to the DEP. Researchers believe the exposure of a number of factors causes larvae to “engulf” the tree trunk after feasting on substances for three months.
The bites on trees from blackflies during the last two summers also helped create a window of opportunity, Gulland said.
The Mexican brown tree moth is not the only moth causing havoc. “This year we are seeing a lot of populations that look like they are connected,” Gulland said. “We are seeing community spiders, parasites, vermin, old bedbugs.”