ELLSWORTH – Last February marked Maine’s first-ever brown tail moth awareness month, a fact that illustrates just how ubiquitous this invasive species has become.
Native to Europe and neighboring countries in Asia and the northern coast of Africa, this spiny pest was introduced to the region by accident in the 1800s. The brown moth population has fluctuated over the years, but it has been in the epidemic phase since 2015, according to the Maine Forest Service. And while they can be found in greater numbers farther southwest in Waldo and Kennebec counties, they still pose a serious threat to the local ecosystem and its inhabitants.
As a caterpillar, the brown moth grows microscopic, poisonous hairs that can cause a severe rash that can last anywhere from hours to weeks if they come into contact with the skin. And the respiratory problems caused by inhaling the hairs can also be very serious. These hairs carry the same level of toxicity whether attached to the caterpillar or airborne, whether the caterpillar is alive or dead. And although there are natural brakes on their population growth, such as a certain fungus called entomophaga aulicae that grows during a cold, wet spring, there is no way to eradicate the species on a large scale.
That’s why organizations like the Hancock County Soil and Water Conservation District and its chairman, Mark Whiting, are urging residents to act now to help nip this problem in the bud.
“It’s a pretty straightforward process to get rid of brown moth nests,” Whiting explained, as he stood this week with Woodlawn chief executive Kathy Young and museum custodian Richard Tupper. Several nests had been spotted on the property.
“From the start of the year to about mid-March, depending on the weather, you can safely touch them because they haven’t developed their hair yet,” said Jake Meir, a consultant forester who was there to help. to location. and the process of elimination. “That’s why it’s so important to do it now!”
The first step is to check your trees and locate the nests, which is not always easy. Nests are often incredibly small and tall. The key is to check if there are one or two solitary leaves near the end of a branch that have survived the winter. Although these leaves may be of stronger stock than their compatriots, it is more likely that they were attached to the branch by the butterfly’s silken web.
Browntail moths weave their nests in early fall, with each nest containing between 25 and 400 larvae. The caterpillars will eventually emerge from these nests after winter and begin to eat the leaves of their host tree, usually oak, apple, crabapple, pear, birch, cherry, or other hardwoods.
“Two years ago the population was much higher and they completely destroyed my garden,” Whiting lamented. “They ate every leaf of every tree.”
This is why it is important to remove nests even if they are high in a tree and unlikely to come into contact with humans. The Forest Service warns that long-lasting tree defoliation and branch dieback are major concerns.
If you are unable to reach the high nests, the Hancock County Soil and Water Conservation District is ready to help. He has purchased a 9 foot long reach pruner and is ready to loan it out for a few days to anyone who needs it. It can be picked up at the organization’s office at 474 Bucksport Road in Ellsworth.
“We bought it specifically for brown moth eradication,” Whiting said. “But if someone wants to prune an apple tree or two of their own while they have it, we don’t mind.”
Once the nest is located and cut, the next step is to carefully remove it from the tree and soak it in a bucket of dish soap-infused water for a few days before discarding it.
“The soap breaks down the casing, allowing water to penetrate and drown the eggs,” Whiting explained.
Burning the nests, while perhaps more satisfying, is not recommended. The toxins can still irritate the skin and would be even more dangerous if inhaled, like burning poison ivy.
Whiting and Weir say any action taken now will go a long way to reducing the brown moth population and preventing damage to residents and their gardens in the spring and summer.