After the coronavirus pandemic, he’d hoped to use the harvest to renew the relationships that have been difficult to maintain over the past year.
But that’s impossible since gypsy moth caterpillars wiped his trees and bushes clean this year. Instead of up to 90 pounds of apples and 18 quarts of berries, Boltz-Robinson says all he has are bare branches.
“Normally the things that I am able to make and pass to friends and family members is not going to happen this year,” he told CNN. “It’s devastating.”
“I grew up in Vermont and I remember some bad years in the late 1980s, and I have never seen anything this bad,” he said.
A legion of larvae
Caterpillars emerge from eggs in the spring and feed on foliage until June or July, at which point they transition to an adult gypsy moth. The adults are alive for a matter of days — just enough time to mate and lay eggs on trees, which will mature through the winter.
Gypsy moths have spread beyond New England, where they were first introduced to the US. According to the USDA, the larval moths are affecting the Midwest, the Northeast, and some Southern states.
This year in particular, the larvae are legion. Officials are calling it the worst outbreak in recent memory.
An infestation of gypsy moth caterpillars can have a ripple effect, Petrice said. As the caterpillars spread, they affect wildlife, timber production, recreation, and the overall health of the forest. And if the population of caterpillars grows large enough, they move on from trees to other vegetation, like crops.
The USDA says that “early detection is critical to limiting the (European gypsy moth’s) spread.”
Several experts who spoke with CNN said that there were small-scale steps that could limit the damage to trees. Boltz-Robinson said that wrapping a tree in burlap sprayed with glue, or with duct tape facing outward, can trap the larvae on their way up a tree trunk.
“It’s effective on a small scale, but if you have 10 acres of trees that’s an awful lot of duct tape,” he said.
Skinner suggested physically removing caterpillar eggs, though recommended wearing gloves, masks, and long-sleeved clothing to do so. Gypsy moth caterpillars have been known to cause skin rash and respiratory problems in some people, according to the USDA.
Drought is playing a role in outbreak
The problem is ultimately environmental. Decker said she is hoping for rain, which would promote the growth of a fungus that kills the caterpillars and keeps the population in check.
If the drought continues, Decker said it is likely there will be more defoliation next year.
“In the 1980s, there was 12 million acres defoliation, and in the 1990s, 7 million acres,” he said. “Between a million and 10 million acres of forests are expected to be defoliated over the next year due to this year’s outbreak.”
What’s unique about the 2021 outbreak, Liebhold said, is that the caterpillars are being found further north than before — even into Ontario, where he said the gypsy moth population is likely the largest.
“Whether conditions have shifted to make them more favorable in the North than the South, we don’t know,” he added.
Boltz-Robinson, the Vermont tree warden, partially attributes the severity of this year’s outbreak to the pandemic and the inability to take preventative measures.
But he also points to climate change. Extreme drought has hindered the growth of some natural funguses that are repellent to the caterpillars, he said.
“And my personal opinion, it’s only going to get worse from here without any significant change,” he said.
Correction: A previous version of this story misquoted Sandy Liebhold on the number of acres damaged in the 1990s gypsy moth outbreaks. Liebhold said it was 7 million acres, not 17 million.