Ep 208. Spongy Moths vs. Tent Caterpillars

Mary Stone answers a question about whether Spongy Moths, formerly called Gypsy Moths, make tents in trees. Not so, though the larvae look similar to Eastern Tent Caterpillars and Fall Webworms. Spongy Moths can completely defoliate and kill trees. Mary shares safe remedies for the creepy crawlies. 

Then, she recounts her brother Rick's hilarious experience with Tent Caterpillars and the identification of another culprit in his rose dilemma—a Scarlet and Green Leafhopper!

Related Podcasts and Blog Posts you'll enjoy:

Related Podcasts and Blog Posts you'll enjoy:

Spongy Moths Vs. Tent Caterpillars – Blog Post

Rose is a Rose Pest Remedies – features my brother Rick's hilarious dilemma

Fall Webworm vs. Tent Caterpillars -  Blog Post 

Ep 71. Diehard Campers - Tent Caterpillars and Webworms 

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I'd love to hear your garden and nature stories and your thoughts about topics for future podcast episodes. You can email me at AskMaryStone@gmail.com.

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Mary Stone, Columnist & Garden Designer
                                        AskMaryStone.com

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Welcome to Garden Dilemmas, Delights, and Discoveries.

It's not only about gardens; it's about nature's inspirations, about grasping the glories of the world around us, gathering what we learned from mother nature, and carrying these lessons into our garden of life. So, let's jump in in the spirit of learning from each other. We have lots to talk about.

Thanks for tuning in, Mary Stone
Garden Dilemmas? AskMaryStone.com
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Transcript

Ep-208 Spongy Moths Vs. Tent Caterpillars 

Sat, Jun 07, 2025 8:45PM • 11:42

00:00

Mary Stone, Hello, fellow lovers of all things green. I'm Mary Stone, and welcome to garden dilemmas, delights, and discoveries. It's not only about gardens. It's about nature's inspirations, about grasping the glories of the world around us, gathering what we learn from Mother Nature, and carrying these lessons into our garden of life. So, let's jump in, in the spirit of learning from each other. We have lots to talk about.

00:26

Hello there. It's Mary Stone and Jolee on the screen porch. We are in a summer swing; although it's not summer officially, we're still in early June here in Blairstown, New Jersey. I want to mention after our last chat about the labyrinth that I mentioned that we've been having an exorbitant amount of rain, and it turns out the total is 11 inches in the month of May when the norm is four inches. So that's a lot of rain, but it's sunny today and bright and beautiful. And it's something that we just have to expect in this life, that Mother Nature has a cycle that she unfolds for us, and we have drought spells, we have rainy spells. And at the end of it all, hopefully, things will be in balance. 

01:09

I want to thank those that wrote back after the last chat about labyrinths, I heard from one of my clients who I designed a labyrinth for. She has yet to build it, but she's got a renewed sense of excitement for when that time comes. So anyway, I have a continuum, in a way, about a story we shared long ago about Diehard campers, that is, the eastern tent caterpillar and the webworms we spoke about way back in episode 71, and it came up from my dear friend Ken Roberts. And it starts like this.

01:32

Hello, fellow lovers of all things green. They're back! While visiting the Karen Ann Quillen home for hospice for our weekly volunteer sing the larva of spongy moths, formerly called gypsy moths, were slithering along the sidewalk. Ken Roberts, my dear friend and partner in providing music therapy, asked if they make tents in the trees. I don't think so. Let me ask Mary. I giggled. 

02:13

Spongy moths don't make the silky tents in trees that we see in the spring and the fall, though, the creepy crawlies look similar. They lay their egg masses on tree trunks, branches and other surfaces like firewood, lawn furniture and even under our car bumpers and wheel wells. Ick! 

02:31

Fall webworms pitch their tents around branches in late summer or early fall and feed on them while camping. And that's interesting because their frass ends up in their tents, and so they look kind of messy as they spend their time during that time. In comparison, the Eastern tent caterpillars make their tents in the spring in a fork of branches and then leave their campsites to eat leaves of nearby trees, returning in the evening or during rainy weather to hunker down so their abodes are tidier. While they both can significantly defoliate, they usually won't kill trees unlike spongy moths. 

03:08

If need be, you can destroy the nest by dropping them into soapy water or using a safe-for-the-environment-contact insecticide, such as Bacillus thuringiensis or BT, a naturally occurring bacterium common in soils. Bt is a selective insecticide that kills caterpillars, while safe for other wildlife, apply the spray directly on foliage and tent nests. It produces proteins that react with the cells of the gut lining of susceptible insects, causing them to stop feeding. Within hours, they then die from starvation, not very kind. Maybe it's best just to let them be. That is how I feel about those native tent caterpillars and the fall webworms because they are naturally here, and so I believe there are self-corrections on them. I don't know of any of them killing trees or shrubs. But I may be wrong about that.

04:03

Think of them as Diehard campers with a nifty life cycle instead of a threat. Besides, native insects are a food source for beneficial birds, adorable toads, and other beneficial insects. It's true; they can be unpleasant when they fall onto your plate at a barbecue.

04:21

Native to Eurasia, unlike many unfavorable insects that arrived here accidentally, gypsy moths were brought here intentionally in the 1860s as a possible source of silk fiber when the traditional silk moth became diseased, Gypsy Moths are now called spongy moths due to their spongy egg masses and to be politically correct, apparently. Their favorite host is Oak. Though they love to feed on many species of trees. Last June, my clients, oak trees in Glens Bay, New York, were leafless. The leaves grew back later that summer. 

04:54

Once the spongy moth caterpillar stopped feeding a healthy tree can survive two or three consecutive defoliation attacks, but it weakens the tree, making it more susceptible to drought and other environmental problems or pests. I wish I had a do-it-yourself solution for spongy moths, but management requires hiring a professional. I spoke with my associate arborist, Dave Dubie, who said that they use BT, requiring an industrial sprayer, of course, to reach the height of the trees. There are chemical remedies, too, but we must consider the environmental impact. They are not selective, you know. So you're killing all sorts of beautiful things.

05:36

So why the name change? The Entomological Society of America dropped the common names of the gypsy moth and the Gypsy ant because, and I quote, The names are inappropriate and offensive. The Romani people, or Roma, are Europe's largest ethnic minority and face discrimination. Gypsy is considered a pejorative term. End of quote.

06:01

I always thought that the definition of gypsy is somebody who moves from place to place in an adventurous kind of way. My mother called me a gypsy when I was on the move during my 20s, bringing my belongings and sending others forward through UPS. It just goes to show that names can mean something favorable to one group and be offensive to another, but surely defoliated trees are sad to see and displeasing to all garden dilemmas. Ask Mary stone.com

06:31

Speaking of defoliating trees, I am sad to say that the beech leaf disease that's been inundating our beech trees here is really doing a number on them. I look out beyond the screen porch, and it just makes my heart hurt because I have so many beech trees. And, of course, you know about Mr. Beach, my dear tree outside of my bedroom window that actually gives a canopy to the house and protects it in the hot summer sun. I've been hugging him. He's about a two-foot caliber, and I look up at the canopy, and I'm telling you, it is devastating to see maybe a third of the canopy not there. It may even be more. And so I am just hoping that there's some resolution and that we can save these beech trees. Because, boy, after the ash tree heartache, how many trees can we lose? It's just so devastating.

07:20

On a happier note, I hope you don't mind if I revisit the hilarious story from my brother Rick about his tent caterpillars. Rick and Paulina live in Knoxville, Tennessee, and Eastern tent caterpillars demolished their potted roses, but it left their other herbs intact. So Rick admitted he had used nasty chemical products in previous years as a remedy. My dear little brother, don't you know better than that, especially around food? So I sent him a link to an earlier story about tent caterpillars titled Diehard Campers and advised him to remove the tent or apply BT, the naturally occurring bacterium we just spoke about that's in soil. Or there's neem oil, a natural alternative to synthetic pesticides. Both are far safer for the environment-- And you, my dear brother. 

08:09

A week later, I checked in on my brother's progress of his rose dilemmas, and it turns out Rick took the advice of his big sister and removed the tent so his annual Caterpillar invasion was preempted without using chemicals yay. However, he said his roses still looked half-defoliated with minimal blooms. I asked that he take a closer look to see if there's tiny brown or green specks, evidence of mites or aphids, none to be found. However, he came across a colorful, green insect we couldn't identify upon closer inspection, he said it's sparking, which made me laugh hilariously. Leave it to an engineer to associate insect activity with electrical currents. 

08:53

Rick quickly hung up the phone to take photos in a video clip, and he sent them to me. Maybe it's not a spark. It kind of looks like he or she is shooting a thread. He then sent a photo of the clear liquid on a decoy leaf of paper too cool to disturb her, even if it's bad for the rose. That's so funny. I still laugh about that. So after we had that exchange, I reached out to my birder buddy, Dennis, who also knows a lot about insects and plants, and he identified Rick's visitor as a scarlet and green leaf hopper. Cool, isn't it? It's found in meadows and gardens. It sucks juices from plants, and it's native. So there you go, the green little beauty can stay.

09:37

Do you have any hilarious stories about spongy moths? There's nothing funny about defoliated trees, but I have a funny memory of attending a comfort zone camp a few years ago. Part of the camp experience is the challenge course, where we go out into the woods and do all these fun activities, and the kids work together as a team to solve these challenges. It's always challenged by choice, but it's fun to see.

10:00

The connections that are made out there. And the kids heard what they thought was a pitter-patter of a drizzle, but the sky was bright and blue that day, so I said to them, it is frass falling from the trees. What is frass, one child asked?  Caterpillar poop.

10:15

It made him laugh. Extrament would have been a more proper way to say it, but talking about poop always gives a chuckle, even at this age. Aren't you glad you're wearing a hat? I said to the little boy. After that, several of the kids snagged their hats out of their backpacks. It was fun, and I do walk around the woods this time of year with a ball cap on. I suggest the same to you so you don't have frass falling into your hair, just saying.

10:44

So, thanks for coming by. I always appreciate our time together, and I hope you enjoy the podcast, and please share with a friend or two so that more can join us and learn and grow in this garden of life. And I am not kidding. I want to hear some of your fun stories. Do you have any siblings that do funny things, like my brother Rick, that was a good story, and I hope you enjoyed it. And I enjoy our visits together each week, and I look forward to next time on the screen porch. Have a great day. 

11:11

You can follow garden dilemmas on Facebook or online at Garden dilemmas.com and on Instagram at hashtag. Mary Elaine Stone, garden dilemmas, delights and discoveries, is produced by Alex Bartling. Thanks for coming by. I look forward to chatting again from my screen porch and always remember to embrace the unexpected in this garden of life. Have a great day.