They are back. Not in our back yard (yet), but that doesn’t mean they aren’t here. If they are up in the trees, we won’t see them for a week or two. Meanwhile, a couple of miles down the road, they are munching away on my son’s trees. He has managed to rescue a beloved old apple tree, but the oaks are going down for a second year.
The cold, wet weather is on our side. I may complain about it because it really sets off the arthritis, but it may save us — to some extent — from the caterpillars. As long as it stays chilly and rainy, there’s a decent chance the invasion will be minimal. If not, it will most likely be worse than last year, something I have trouble imagining and which has both of us seriously creeped out.
Garry isn’t normally afraid of bugs, but he has developed a healthy loathing for these invaders.
Last year, they ate about 350,000 acres of hardwoods. If the weather dries up and the temperatures go up, they could easily knock off twice as much this year. Many people have been spraying and every little bit helps. We’ll get sprayed again, probably next week.
If you live in New England and you are seeing well-grown caterpillars — they would be the ones showing blue and/or red dots on their back — I’d appreciate you letting me know where you are and how bad it appears to be. Right now is when we would be heading into the worst of the invasion. June is the month. The caterpillars feed well into June, at the end of which they pupate and form cocoons.
The 2016 outbreak was the largest gypsy moth outbreak in the state since the early 1980s. In the 1980s, the damage was even more widespread, with 900,000 acres of woods stripped in 1980 and 2 million defoliated acres in 1981.
More recently gypsy moth damage hasn’t been as bad because, since about 1989, a caterpillar-killing fungus has greatly reduced their numbers. But drought conditions in 2015 and 2016 reduced the fungus’ ability to infect young caterpillars and the population boomed. This spring’s cool, rainy weather has the potential to save us. The fungus might make enough of a comeback to dent the caterpillar population for the remainder of 2017.
Neither of us remembered the 1980s invasions. Garry was living in Boston in a high-rise in the 1980s while I lived in Jerusalem. That’s probably why it took us so long to figure out what was happening. I looked through my posts from last year. This was approximately when we started to realize something ugly was happening. Between the end of May and a week later, I stopped leaving the house. At all. Three weeks later, the caterpillars had eaten every leaf on every tree.
These invasions are usually a couple of years which run together. The second year is typically worse than the first.
I’m trying not to make myself insane with worry, but it is hard not to worry. Ignore my complaints about the cold, wet weather. Bring on more cold wet weather. Keep it wet and keep it chilly. It’s our best defense against the killer creepers.
The caterpillar pictures Garry took at our house were as of June 9, 2016, the beginning of the worst part of the invasion. We aren’t there yet, so all we can do is hope … worry … then hope a little more.
What is a gypsy moth?
It’s a species of moth native to Europe and Asia. Historians believe they were first introduced to Massachusetts by Etienne Leopold Trouvelot, a Medford-based amateur entomologist who tried to breed a hybrid gypsy-silk moth in the late 1860s. To say that his attempts to produce a silkworm went wildly awry doesn’t begin to cover the damage that has resulted from his doomed experiments. Gypsy moths have spread across the continent, down into Mexico and up into Canada, including Alberta.
Why do I keep hearing about them?
Last year, Massachusetts saw its first major gypsy moth infestation in 35 years. A specific variety of fungus typically keeps the invasive species in check, but a statewide drought last year kept fungus levels low and allowed the gypsy moth population to balloon. And as of late last month, scientists said this season’s eggs are beginning to hatch—setting the state up for another bout with the creatures. Unless the bad weather keeps them in check, this could be a very bad year. Worse than last year.
What’s the big deal about some moths?
Gypsy moth caterpillars are responsible for mass deforestation. Last year, they stripped leaves from more than 350,000 acres of trees across Massachusetts, with the heaviest concentration in eastern and central parts of the state. They favor oak, aspen, apple, and willow trees, especially. Full-grown gypsy moth caterpillars are 1.5 to 2 inches long.
A single larva can consume as much as a square foot of leaves per day, according to the University of Illinois Extension website. Last year, we could actually hear them chewing. It’s a horrible sound.
The caterpillars go on to produce a proportional amount of fecal matter, which can make it impossible to enjoy outdoor activities. The trees are left bare, limiting autumn foliage and allowing sunlight into parts of the woods which are normally shaded. Not good for plants or animals.
Any danger to people?
Yes. Although gypsy moth caterpillars do not bite, they frequently cause a red, itchy rash. Garry got a nasty one last year on his arms. The rash can last a few days or weeks. Wear long sleeves, a hat, long pants, socks, closed shoes, and gloves if you need to handle them. If you develop a rash, take antihistamines to relieve itching, or see your doctor if it’s very bad.
Is there anything I can do to keep them away?
If you spotted gypsy moth eggs in your trees earlier this year or late last year — Massachusetts Wildlife Magazine describes them as “tawny brown egg masses”—now’s the time to call a tree care professional, who can safely apply pesticides to keep the caterpillars at bay. Mass Audubon also suggests a number of DIY solutions.
And regardless, if you were invaded last year, there’s every reason to assume — whether you see them or not — they are on the way.