Another Vermont Drought Bummer: Very Hungry Caterpillars Defoliating Forests

A large patch of defoliated trees on a hill near my 
house in St Albans, Vermont. Gypsy moth caterpillars
are laying waste to stretches of forest in the state
this year. Dry weather is partly to blame for 'the
resurgence of this pest.

 Especially if you're in the Champlain Valley, you've probably noticed it.

Big patches of normally green hillsides are brown and leafless. Or, if you're particularly unlucky, the trees in your yard are getting devoured and caterpillars are pooping all over you if you step outside.  

They're gypsy moth caterpillars, and they're causing the biggest defoliation in Vermont since 1991.

The dry weather this year is largely to blame. So yeah, another problem created by drought or near-drought. 

A happy fungus took hold in Vermont in the early 1990s that goes after gypsy moth caterpillars, keeping them in check. If you have a succession of soggy springs and early summers, you still get those little hungry buggers, but they are reduced and number and the trees and forests stay more or less intact. 

Recent springs have been dry,  especially last year and this year, so the very hungry caterpillars have come roaring back.  

Sure, it rained early this week, which is nice, but that's far too late and too little to do much to encourage that wonderful caterpillar-killing fungus.  (The quarter inch of rain that fell on St. Albans yesterday was less than in other parts of Vermont, helping cement my town as part of the Great Champlain Valley desert).

Even worse, now that the caterpillars are back with a vengeance, they might stick around for a few years. Lots of wet weather this summer and especially next spring and the spring after that would help a lot. 

I know we like bright, sunny spring weather, but I hope spring, 2022 is just one long slog of foggy, drizzly days. 

I've got selfish reasons for that. There's a big patch of defoliated trees on the hill above my house, and it's creeping closer to my property. 

The trees around my house give me a great deal of privacy in the summer, which I love. Plus, some of the trees aren't the healthiest.

Most healthier trees can survive a season or two of defoliation, but ones that already have pre-existing issues often do not. Newly planted trees are also in danger. 

We sure picked the wrong summer to spend lots and lots of cash to plant a nice big river birch in our St Albans yard to replace the willow that blew over in a storm a couple years ago.  Despite lots of watering, it's suffering from the dry weather, and gypsy moth caterpillars love munching on river birch. Sigh. 

The gypsy moth caterpillars will wrap up their destruction  later this summer, but who knows how many years this problem will last before that wonderful fungus can gain the upper hand?

It's not just us having this problem, by the way. Parts of Ontario, Quebec, Wisconsin and New York, among other places, are having a battle royale with the caterpillars. 

If you have some prized trees, there are only a few things you can do about the problem. You can wrap burlap around the base of trees so egg masses are laid there instead of in the tree.  Then later on, you can remove the burlap and destroy the egg masses. Putting caterpillars and their egg masses into soapy water kills them. 

Experts say the Great Vermont Gypsy Moth Caterpillar Munchathon will continue for about another month before it wanes.  Those buggers will turn into moths, then regroup to torture us next year.