I don't have many answers but can sympathize as I found a very large caterpillar on my garage door yesterday. After getting really hit hard by winter moth AND a huge bump in the tick population in our yard, I'm exhausted and it's only May! I remember when I was little that my grandmother had severe allergic reactions to touching gypsy moth caterpillars accidentally.

I'd like to hear anyone's experiences with BT as well since I believe it also treats winter moth and perhaps this is the year to try to make a dent in both populations.

Thanks, thyme2dig. I think our tree is in the large but not overwhelming quantity category. Most of the leaves look about half eaten so far, and near the top they are almost completely gone and already sprouting a second flush of leaves. I have only found a few actually in the yard though. I'm pretty sad for the tree. Good idea to contact the extension office.

I happened to be in Plymouth today and the number of gypsy moth caterpillars was truly astounding. Some trees literally had one on each leaf. A few trees were 100% defoliated. I saw a building with hundreds crawling on the walls. My oak tree is nothing like that--at least not yet.

http://www.biocontrol.entomology.cornell.edu/pathogens/entomophagamaimaiga.php

Not available commercially at this time.

I'm in the south end of Plymouth and the gypsy moth caterpillars are bad here; dropping down on my deck among other places. Not horrendous, just annoying. I have another reason for wearing a sun hat - it keeps the caterpillars out of my hair.

A big part of the problem is that it's been extremely dry here with most of the recent rain staying to the north or the south. Wet conditions encourage the fungus that kills the caterpillars; dry conditions let the caterpillars run rampart.

According to the UMass Factsheet - Gypsy Moth

"During wet springs, an entomopathogenic (insect killing) fungus (now "naturally" common in Massachusetts), known as Entomophaga maimaiga,
works extremely well in keeping this pest in low numbers. Observing
dead gypsy moth caterpillars that are hanging head-down on the trunks of
host trees is a good indicator that this fungus has been effective."

All of the caterpillars I've been seeing are extremely robust and healthy, although the grackles have been foraging in the grass - hopefully eating the caterpillars.

Claire

The first several years I lived in NH (early 80's) we had some really high gypsy moth populations, with so much dropping frass in our wooded area that it always sounded like it was raining for a few weeks. When going out a doorway, in order to not be festooned with caterpillars, we had to brush aside threads of hanging caterpillars that were dangling from the eaves, and I tended to avoid walking under trees as much as possible. Completely icky, and due to the multiyear infestation, white oaks in particular were killed by repeated defoliation. We burned white oak in the woodstove from standing dead trees for years. We have since had one more wave, less intense, but in general, there seems to now be a manageable balance between the gypsy moths and the diseases that keep the population from killing trees via total defoliation in our area. I still see a few caterpillars every year and step on them, but there haven't been a large number for quite a few years here.

We used strips of special tape and Tanglefoot to reduce the number of caterpillars climbing the trunks of yard trees, scraped the fuzzy tan egg clusters into containers of soapy water once the adult moths had done their thing, and in one case wet down a larger tree with the hose and used an industrial fan to blow Bt up into the foliage to reduce its defoliation. Bt works best if the caterpillars are still tiny; once they are large, I don't think it is able to kill them, though they may not be as healthy. You might check to see if there are pheromone traps available to reduce the adults and therefore the number of eggs for next year. Here we couldn't protect the woodlands, just the yard trees from the worst of the infestation.

Claire, sorry, but we didn't find that any of the birds seemed to like the caterpillars, perhaps due to their spines, but we don't generally have starlings, so I hope that you find your starlings like them.

I found this site from Michigan State University:
Natural Enemies of Gypsy Moth: The GoodGuys!

which talks about all sorts of predators and parasites, birds, mammals, insects, fungi, viruses, etc. I just hope some of them will either eat the caterpillars or eat the pupae before they can hatch into moths and reproduce.

Claire

The caterpillars have devastated the oaks in my yard here in Plymouth. My deck is under an oak and the frass is littering part of the deck (I do sweep it up, again and again). Luckily I have an overhang and an umbrella so I can stay out here without getting covered.

The frass-fall is lessening and I'm hoping the caterpillars will pupate soon. I saw a dead caterpillar this morning so maybe the fungus or the virus is beginning to affect them.

The grackles have failed me! I count on them to eat winter moth caterpillars, and I think they do, but the gypsy moth caterpillars haven't been eaten. I need to revisit the contract with the grackles - they've been eating a lot of seed and suet and I expect pesticide services in return.

I'm worried about the continued droughty conditions. The trees will need water to leaf out again and rain is sorely lacking.

Claire

I just checked the Michigan State link above and this is a screenshot of caterpillars killed by the virus:

Claire

If it's any comfort, we usually had better years after particularly bad years because the disease levels increased so the surviving gypsy moths and their caterpillars decreased in the following years. My sympathies to you and your trees. Let's hope for a good several days of rain!

Check the tree trunks and start the killing.

"What can you do now? Look on tree trunks and destroy gypsy moth pupae and caterpillars that are covering themselves in silk."

URI Entomology Caterpillar Update

Steve

Thanks, Steve. Not a chore I look forward to.

Claire

Article in the Globe this morning:

For this massive caterpillar invasion, it’s crunch time

Claire

Claire, a spoon and a container of soapy water will do the trick. You don't have to handle them or squish if you prefer not. It's kind of meditative.

Just curious, is one person's removal of caterpillars likely to make a difference? Perhaps Claire can save herself the trouble. I know for some things, especially insects that don't travel far from their hatching sites, it really can make a dent. (For instance, Asiatic garden beetles, which I hand picked at night for 3 years, and this year had a *much* reduced population eating my June flowers.) For other things they say it's really the population as a whole, rather than any one tree or yard, that needs to be affected. If that's the case we have to hope for a wetter spring and an uptick in the fungus...

Good point, lalala - I haven't seen an answer to that question, although the oaks across the street are much less devastated than the oaks in my yard so it may be a localized phenomenon in my immediate neighborhood.

I didn't see a bunch of caterpillars and pupae on any tree trunk, so they must have found other places to assemble to pupate where I couldn't see and destroy them..

I'm now seeing large numbers of gypsy moths flying; presumably the males since the females are flightless. They all seem to be fairly dark colored as the males are.

I've only seen one white one, which would be a female, and it was fluttering but not flying. I'll have to check that spot in the morning to see if she laid any eggs.

The caterpillars are almost all gone although I did find one crawling on my neck this morning after I came in from feeding the birds.

I read somewhere that the female caterpillars grow larger than the males and pupate later, so I'm hoping that the virus will have infected the females. I've seen two caterpillars killed by viruses so far. Probably just wishful thinking but I'll take any hope right now.

Claire

I did check the spot (under a deck railing) where I saw the female gypsy moth, and she did indeed lay eggs there. I scraped them off with a paint scraper.

And then I looked up at the nearby oaks and saw a few areas about twenty feet high where there are a whole lot of female gypsy moths stationary on the bark, with male moths flying around.

In one area there seem to be masses of eggs and what looks like developing pupae as well as adult female moths.

I'm guessing this is why I never saw bunches of larvae and pupae - they were all high up on the trees. None of these areas are reachable and I'm sure there are more on the trees on the coastal bank so the best hope is for a rainy spring next year.

I am not happy.

Claire

Ugh, so sorry, Claire!

This is beginning to feel like picking at a scab, but I wanted to update the progress of gypsy moths in Plymouth.

The females have been out for a while and courted by the males and are still laying eggs.

This female chose the underside of my stool as a good spot to lay eggs. I did not agree so she was evicted before she could lay eggs. Luckily I saw her fluttering while she climbed.

And the rubber bird bath is apparently a desirable location. I flush and refill it every day but I hadn't been looking closely at the sides when I fill it - I approach from the top with the hose and just sluice it out. I should have looked more carefully.

This is getting surreal.

Claire

For those who want to do something about the gypsy moth eggs before they hatch next spring (besides begging for a wet spring so the fungus kills the caterpillars), I've found a lot of information mostly leading to spraying the eggs with a horticultural oil product.

If the egg masses are on a flat surface it's easy to scrape them off and dump them in a bucket of soapy water, but if they're on tree bark it's a whole different story. This is not really scrape-able without damaging the tree.

The Virginia Cooperative Extension has a good page:
Gypsy Moth Management for Homeowners on Small Properties

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Egg mass treatments (prior to egg hatch)

Since each egg mass contains from 500 to 1000 eggs, destruction of egg masses before hatch can have an impact on populations. Starting in the fall, search your property, including trees, outdoor furniture and play equipment, for egg masses. In some areas of VA, eggs hatch as early as mid-March, so egg masses must be destroyed before that time.

• Using a putty knife or similar tool, scrape the egg masses into a plastic bag or can. Once collected, empty the contents of the bag into a container of soapy water (dish soap works well) and soak for a day or two.

• An option to physically removing egg masses is to saturate egg masses before hatch with a solution of horticultural oil labeled for gypsy moth (available at garden stores). This will smother the gypsy moth larvae (caterpillars) within the eggs. This solution is available commercially as Golden Pest Spray Oil® (Stoller Enterprises, Inc.), or you can make your own using soybean oil and water (1:1). Use a small spray bottle, household sprayer, or "supersoaker" water gun to soak the egg masses.

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I ordered the Golden Pest Spray Oil and I think I'm going to get myself a supersoaker water gun (might as well enjoy the process).

Claire