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May 1—Aerial spraying to tamp down an infestation of the forest-killing spongy moth in Waynesville and Maggie Valley has been bumped back to the second half of next week.
The spraying in Haywood County was originally scheduled to start May 2, but treatment crews have to finish up a job in Virginia first. So May 7 is now the earliest that the helicopter could begin making the rounds here.
"These anticipated start dates are often very fluid since weather and other factors come into play. A May 7 start is our best guess right now, but that is not set in stone," said Andrea Ashby, with the NC Agriculture department. (See below to sign up for a text notice the day before spraying begins.)
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Spongy moths — the invasive pest whose caterpillars can defoliate and destroy large sections of forest — are on the rise in Haywood.
Aerial spraying from a helicopter will be deployed starting Friday to hopefully tamp down an explosion of the devastating moths in the Waynesville and Maggie Valley area.
The spraying will target 5,990 acres where an alarming uptick in the moths was detected last year. The swath lies along the south side of U.S. 19 in Maggie Valley, goes up the mountainside to the ridgeline and back down the other side into the Eagle's Nest area of Waynesville, then runs south following the ridgeline to Balsam.
"We chose those spots because they're where we caught the highest number of moths and the elevation range is about the same — meaning the trees in those areas are leafing out around the same time, and the caterpillars are all about the same age and size, making the treatment as effective as possible," said Sara Lalk, forest health research specialist with the N.C. Department of Agriculture & Consumer Services.
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And Lalk isn't kidding about catching a lot of spongy moth caterpillars in the area. Her team trapped 13 male moths there in 2023. That number had exploded to 2,627 the next year.
Left unaddressed, the infestation could mean bare trees in as little as two years, leaving the affected forest vulnerable to other types of destructive pests.
What to expect
The aerial treatment operations are now slated to begin around May 7, and would take about three days.
About 2,560 commercial or residential lots lay within or just outside the treatment area.
Residents in or near the treatment area can expect to see a low-flying helicopter making frequent passes overhead for eight hours a day during the treatment dates. The choppers will be low — just above tree canopy — and might occasionally disappear for refueling. And if it looks like the helicopters are spraying the same area over and over again, don't be alarmed.
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"A helicopter treatment swath is about 125 feet wide, so they may look like they're working in the same area for a long time. Managers have a display that shows treatment progression, and we can watch them 'color in' the treatment block as they move back and forth," Lalk explained.
Due to the nature of the biopesticide being used, a helicopter's slower speed and lower height make it a better tool for effective dispersal than a plane. There's an added benefit, Lalk explained.
"The rotor wash from the turbulence created by the helicopter allows better coating of the little droplets on the leaf surfaces," she said. "More droplets on tree leaves means more chances for the spongy moth caterpillars to feed on them, which means fewer make it to adulthood to possibly mate and lay eggs."
The helicopter will be spraying Bascillus thuringiensis var. kurstaki — a naturally occurring soil bacteria which is fatal to spongy moths but harmless to people, plants, pets, livestock, and wildlife.
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A different approach
In 2023, the aerial spongy moth treatments were conducted over Cruso. It was originally planned for 2022, but postponed for a year due to public opposition. An education campaign quelled fears in the intervening year, including enlisting the public to participate in moth trap checks to see the problem for themselves.
The treatment in Cruso used a "mating disruptor" that confused male spongy moths and interrupted their ability to find a mate. But the Waynesville and Maggie spongy moth population is too robust for that.
"Once the populations are high enough, the mating disruptor no longer works because there's so many moths and they can still find each other. So then we move into this next layer, this biological control agent," Joy A. Goforth, plant pest administrator at NCDA&CS, told The Mountaineer earlier this year.
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Goforth stressed that Bascillus thuringiensis var. kurstaki is "perfectly safe," and that people should have "no concerns whatsoever."
After discovering the population boom last year, the NCDA&CS held an information session over the winter for residents in the area.
To check if you are in the treatment area, or to request an email or text in advance of treatment, visit ncagr.gov/proposed-spongy-moth-management.