‘WE’RE SO GOOD at pretending the things around us are known and boring, or imagining that the worthwhile things are far away,” says Sam Jaffe, at the start of the documentary film “The Extraordinary Caterpillar.” Sam begs to differ, however, and in the film, as in his work as founder of The Caterpillar Lab, a non-profit educational and research organization, he shows us just how extraordinary—and essential to all of us—they are, and how a diversity of them are right there to discover in our own backyards.

It’s a good time of year to focus on caterpillars, as we gardeners make decisions each fall that can support—or threaten—their survival overwinter, and so that’s what we’re going to do today: talk caterpillars, with Sam.

Plus: With Sam, and Homegrown National Park’s Doug Tallamy, and other caterpillar experts featured in the film, I’m moderating a webinar conversation on Weds. Oct. 14 at noon Eastern—and if you sign up you’ll receive a limited-time link to watch the film in the days leading up to the event. All the registration details are here; how you can host a private group screening is detailed at this link.

Drawing on his education in ecology and evolutionary biology plus a natural gift for teaching others, Sam Jaffe is the founder of the New Hampshire-based Caterpillar Lab nonprofit. He also has an incredible talent for macro photography and videography—which comes in handy when your life’s work is centered on caterpillars. Sam is one of the experts featured in the documentary film “The Extraordinary Caterpillar,” which was conceived and directed by Jeff McKay of Edgeland Films Inc. and co-produced by Merit Motion Pictures. That’s the film’s trailer, up top.

Read along as you listen to the Oct. 12, 2026 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on Apple Podcasts (iTunes) or Spotify (and browse my archive of podcasts here).

(Below, photo of Sam from “The Extraordinary Caterpillar” documentary.)

extraordinary caterpillars, with sam jaffe

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Margaret Roach: Hi Sam, and thanks for coming indoors to talk to us. How are you?

Sam Jaffe: Good. Thanks for the introduction, and excited to talk to you about caterpillars today.

Margaret: Yes, the best [laughter]. So to get started, I wanted to tell people briefly about what The Caterpillar Lab is and then also how the documentary film “The Extraordinary Caterpillar” came about. So The Caterpillar Lab I guess first.

Sam: It’s always a challenge to define it. Usually in our second-grade class visits, I define it as a strange little place in New Hampshire where you walk into a building and all of a sudden you’re surrounded by native plants, caterpillars munching away, just native insect stories all over the place, but that’s just sort of its physical location.

So we’re an organization built around just exploring this subject of native New England caterpillars from every angle you can imagine. Our main mission is to get out there and teach people about them, show them that they’re here, get them excited about native insects, but we end up collaborating on research projects.

We advise on art, film, and photography. In the early days, one of our first projects was advising on a strange New York-based dance [laughter] focused on the defensive adaptations of caterpillars. So it can really go anywhere, but it surrounds this resource of charismatic creatures that few people get to experience.

Margaret: And they are charismatic, my goodness. When you start really looking and taking the time to be still and watch, they are charismatic. So let’s talk about them and how they work. Entomologist Doug Tallamy of the University of Delaware and Homegrown National Park nonprofit, he’s another voice in the new film. He calls them “the bread and butter of terrestrial food webs,” because they transfer more energy from plants to other animals than anybody else does, I guess. How do you describe them? Who are they [laughter] in the big scheme of things?

Sam: There’s so many ways to describe them and so many different reference or starting points for it. I try to go a little bit more basal than caterpillars are for the birds, and just start with that they’re amazing. As you mentioned, as I mentioned, they’re charismatic, they’re weird and wild, and they’re sort of all around us. So before we get into why they’re important for the ecological world, I just like to celebrate that some of them have fake eye spots, or inflatable tails, or go through these incredible transformations that are inspiring to watch.

So it’s always important to me to celebrate them for just what they are in isolation, and then you can build on that and you can say, wow, these already cool creatures that are fun to go out and see for the first time for ourselves are also supporting all of the birds we care about, that they’re moving energy from the plants to the rest of the ecological world in this major way.

So to start with just that, they’re cool. [Laughter.]Margaret: They are cool.

Sam: They’re beautiful, they’re worth knowing, and then to show that they’re indispensable both to other things we care about in the environment and to ourselves as well. So that’s usually my entry point.

Margaret: And I have to confess, I’ve been gardening many decades, and so I’ve seen a lot of caterpillars. And when I first started gardening, it was like, “Oh, caterpillars, they’re bad. They’re eating your plants.” That was the mindset. And I didn’t believe that because whatever, I was an organic gardener and I didn’t kill things and so forth [laughter]. But even the most common ones, the ones I kind of feel fairly confident that I’m going to see every year, like the last week or two, it was like woolly bears—Isabella tiger moth caterpillars, is that right? [Above, collage from The Caterpillar Lab.]

Sam: Yes.

Margaret: So the woolly bears, it was like you could barely walk a few steps where I live without seeing one inching along the ground. They were everywhere. So I think that was something to celebrate, but I also wanted to understand it. It was like, why are you all out at this moment? Who sent the message to you all to do this [laughter]? What are you doing all you guys?

Sam: Yeah. I mean, part of the fun of caterpillars and insects in general is their extreme diversity. So there’s always another caterpillar. And at any season, spring, summer, fall, mid-winter, there are caterpillars that are active living their lives in their own particular schedules.

And right now you’re just seeing this moment that belongs to the woolly bears. They’re finishing feeding for the fall and they’re wandering everywhere looking for the perfect place to overwinter. This year in your area happens to be sort of like a boom year, so there’s a lot of them around. Next year, maybe there won’t be so many because all those caterpillars you’re seeing now are also ending up feeding predators and parasitoids. But you’ve got this little story playing out with this one species and there are all these other stories playing out as well. Things you’re not seeing, for instance, as the woolly bears are wandering.

There’s also all these inchworms that look exactly like twigs that are settling down on the foliage and on the branches for winter, where they’ll just stay as caterpillars up on the branches, and they’re just harder to see. So the woolly bears interact with us and the way we move around the world during the daytime, and all these other secrets exist to uncover as well with that as a good starting point.

Margaret: Now, by the ones that look like twigs, do you mean the so-called twig caterpillars, like the geometrid moth ones? Is that what you mean, or do you mean something else? [Above, collage from The Caterpillar Lab.]

Sam: Yeah, so for the twig caterpillars or the twig mimics, this time of year, there’s a whole host of geometrid inchworm caterpillars that grow about half size, so they’re only half developed, and then they slow down, they stop eating, and they just rest all winter long, freezing and thawing and don’t feed again until the spring. So it’s wonderful for me to know in the wintertime I can go out and still find some caterpillars because I’m the type who gets pretty low in the winter if there’s not enough insects around, so I’m motivated to go find them. But it’s also really important for the birds. Some of your listeners might know about black-capped chickadees and especially golden-crown kinglets, these tiny little insect-eating birds that spend the winter up here. And those twig-mimicking geometrid caterpillars that are out and exposed in the winter, that’s their main diet all winter long.

Margaret: I had no idea. See, this is what I mean is I know them and I see them and when I catch one, when one doesn’t deceive me with its sort of cryptic appearance and I suddenly clue into it and go, “Ah, you’re not a twig,” but I didn’t know that they were food for the birds in winter. I didn’t know that.

Sam: I think that most of us know a few of these stories well. You might have heard about the woolly bear or the life cycle of a monarch butterfly and its migration, but it’s important to remember that we have maybe 3,000 to 4,000 species of moths and butterflies in just New England up where The Caterpillar Lab is. Each one of those has its season, its predators, its story, its interaction with the environment that’s as large as that of the woolly bear or the monarch.

So it’s not even about knowing all the stories coursing through your backyards. It’s just to start to recognize that you can’t know them all, but there’s always a next one. It means our yards are frontiers. We go out and we get to discover something new, whether it’s for ourselves or for the world, something completely unknown, but there’s always more stories going on. So if you think you’ve found them all, just turn over a log in the backyard [laughter] and you’ll start finding more.

Margaret: Yeah. I mean, I love asters. I love the time of year for the asters, but also I came to understand after enough years of seeing it at the same time, I would see this very colorful caterpillar, not hairy, unlike the willy bear, the brown-hooded owlet moth caterpillar, I think, and just beautifully colorful like this rainbow on the asters. And it was reliable. There it was. There were my asters and there were these…[laughter].

It was just to know about these synchronicities and to come to expect not just flowers, but also the creatures who utilize the flowers and start to get the idea of, oh wait, this is all connected. I mean, I think that’s the big wow. [Above, collage from The Caterpillar Lab.]

Sam: This may be a unromantic way of putting it, but sometimes I feel like we go shopping for caterpillars here at the Lab a certain time of year on a certain flower in a certain place with a program coming up and we want to showcase a story. We get to walk to that edge of a meadow, find the right kind of goldenrod, and there’s your brown-hooded owlet, this vibrant creature. Or you go out into the middle of the meadow and there’s the asteroid outlet. If you were two months earlier, you’d have the gray hooded outlet.

So these caterpillars, they all have, again, their little stories, their habits, their seasons, their host plants. I just add to an internal library or checklist of, O.K., what’s the month? What’s the host plant? What’s the weather? What’s the time of day? And what little creature can I go and see?

Brown-hooded owlets though, they’re strikingly beautiful, definitely one that people notice. And I’m just trying to think, we’ve got quite a few in the Lab right now and been bringing them around to programs. And I feel like by showing them through photography and film and at a live event here at the Lab, we hope that people meet them for the first time and then they start to see them and engage with them in their yards and the landscapes around their houses more naturally than they had before.

Margaret: So as I said, that’s one that doesn’t have hair—setae, is that right, S-E-T-A-E? Is that how you say that?

Sam: Yes.

Margaret: So it doesn’t have setae, doesn’t have what people sort of read as bristles or spines or whatever, so unlike the woolly bear. So if I’m a caterpillar and I’m everybody’s favorite food, like that Doug Tallamy quote I said about the bread and butter or whatever of the terrestrial food webs, how do I manage? The setae are one way I think to manage—me being bristly and so forth—is one way to manage not getting eaten. But what are the other ways that I manage not to get eaten if I’m such a popular food source?

Sam: Yeah, pretty much everything you see when you look at a given caterpillar has evolved from these interactions between species. So it’s not just like, oh, here’s a landscape and a temperature and you get a caterpillar that looks like this. You have a caterpillar that’s on a particular host plant and it’s being eaten by particular things, whether they’re birds, wasps, flies, stinkbugs, spiders, all this pressure from above. And to survive, they have to evolve defenses.

But it’s like the particular ingredients of where they are, when they are, and what’s eating them leads to different types of defenses evolving. So you’ve got these hairy, spiny, itchy caterpillars. A lot of those defenses are geared towards birds and mammals. You also have caterpillars with bright, false eye spots, making them look like snakes to try to fool birds. And you have others that have physical defenses, like little antlers they whack side by side.

There’s one, the Harris’ three-spot that wears its old head capsules after it sheds its skin as a hat [laughter], and it uses those to hit things. And those defenses might be geared more towards little parasitic wasps and flies trying to lay eggs into the caterpillar.

So when you see a caterpillar and it’s different than the one next door, those differences are usually related to how it’s evolved to defend itself, and how that sort of flows relates a lot to the host plant they eat and what’s eating them.

Margaret: Yeah. So I’d love to talk a little bit about their life stages and especially as it’s fall, we talked a little bit about surviving the coming winter. But can we just go through the different stages in the life of a caterpillar? And you have, by the way, you have some wonderful, under the Resources tab on your website, on the Caterpillar Lab website, you have some wonderful PDFs and so forth for people who want to dig in and learn more. There’s lots of good stuff.

Sam: Yeah, we created a special pupation resource, because there’s a lot of misconceptions about the middle life stage.

Margaret: Yes.

Sam: So a quick overview is that we’ve got adult moths and butterflies that mate and lay eggs. Those eggs hatch into early-instar small caterpillars that eat, shed multiple times as they grow going through these different instars or growth stages, eventually pupate going from the caterpillar or larval stage to the pupa or chrysalis as it’s called for butterflies stage, and then those emerge as adults.

So they all go through this four overall life stage cycle, but they do it in different ways over different amounts of time and definitely interact with the seasons differently. So there’s no one way to overwinter or one life stage to get through the winter. There’s no one duration for how long is a caterpillar going to be a caterpillar. It varies tremendously species to species.

So like with your brown-hooded owlets through most of New England, they’re going through two generations a summer. So you’ve got pupa that overwinter. We’ve got the caterpillars feeding in the early part of the summer, they  pupate again. Then they emerge as an adult moth that mates lay eggs, and you get this two-cycle series in a summertime before they overwinter as a pupa.

In New Hampshire, again, for luna moths here, we have one cycle a year. They overwinter as a pupa inside of a cocoon, but they can’t make a second generation in the summertime. And we were just earlier talking about the woolly bears and the twig caterpillars that overwinter as in their caterpillar form. So how they get through a season varies, but the basic life stages don’t vary very much.

The reason we did that pupal resource is that a lot of people have been taught that a pupa or a chrysalis are more like a pod that a caterpillar creates as a house around itself before it melts down into a puddle and reforms as an adult. Whereas really a pupa is a distinct life stage. The caterpillar actually becomes the pupa. It doesn’t form it. It becomes it internally, sheds the old caterpillar skin away, and the pupa stage really acts a lot like the bulb of a plant.

I wonder actually, we have a nice analogy to a tulip bulb for the life cycle. Would that suit your listeners, do you think?

So yeah, trying to define the role of each life stage has been a challenge. So thinking it in terms of plants, we’ve got the caterpillar, which is the energy-gathering stage. So think of the leaves of a tulip making energy from the sun and having resources come up through the soil. The caterpillar’s like that leaf. It’s gathering the energy and it’s growing. The pupa stage is very much like the bulb of a tulip. It’s made for storing energy and moving that energy effectively through time. So the caterpillar’s gathered all the energy. It stores it as dense fat storage in its body as it becomes a pupa. The pupa’s quiet, it’s resting, it’s waiting for the right time to then develop into the adult.

So pupa stage is a great way to get through a dry season, a wintertime, or just to wait a little while to make sure all of your potential mates are active as well before it uses that energy to become the adult.

So caterpillar’s the leaf, the pupa is the bulb, and then the adult would be like that brief flower, getting the reproduction done and starting the next generations. [Below, various butterfly and moth pupae from The Caterpillar Lab website.]

Margaret: Now, what about, you didn’t use the word cocoon anywhere in there. Do some make cocoons and pupate inside them? Where does the cocoon fit in? Because you said chrysalis, which I think is sort of the butterfly’s protective device [laughter]. I don’t know what you call it, but do you know what I mean? What’s a cocoon and where does that fit in?

Sam: So you were halfway there. So a crysalis is a pupa. We just have another name for a butterfly’s pupa. So it is the animal. If listeners know that beautiful green chrysalis of a monarch with the little gold dots, that’s not a case or a shell. That’s just the animal right in front of you. That’s its skin you’re looking at.

A cocoon is quite different. A cocoon is a survival strategy. So some caterpillars will bore into the soil to pupate underground. Some will go into solid wood. A lot of butterflies pupate out in the open. They’ll hang from a “J” or harness themselves by silk and then become a pupa. But some species of moths will actually build a case around themselves out of silk. It’s just their spit that hardens into string basically. And then they become a pupa inside of that.

So cocoon is a house, it’s a survival strategy. The pupa is the animal itself that’s going through these changes to grow up.

Margaret: O.K. And so the silk is just spit [laughter].

Sam: That’s a fun way of putting it. There’s the idea that it’s worm spit. There’s a special silk gland. There’s an organ in the body that produces this clear fluid in a bag basically that comes out as a liquid and then immediately hardens. Silk can be used to build a cocoon, to create little lifelines to their host plants, to build a walking trail so caterpillars can get across a smooth surface. Silk is a very multipurpose tool that they have. I’m sometimes jealous that we can’t do more with our spit watching these creatures invent new waves to use silk.

Margaret: Well, and I mean, I’m totally overwhelmed by spiders’ capability to construct webs. That’s another one, but it’s like, wow, really? How do you do that without tools, without materials from the hardware store [laughter]?

Sam: Right. And caterpillars are doing it in so many different ways. I know there’s currently research going on and caterpillars as primary shelter or builders or structure makers in the environment. So you see all these rolled leaves and weird little tents, two leaves sandwiched together. That’s usually a small caterpillar making a shelter out of silk, tying leaves together. And now we know that those shelters are repurposed and used by other insects and spiders and all kinds of things later on as well. So their use of silk goes beyond most other insects’ use of silk, and it creates these new structures for them to live in.

Margaret: I want to talk about this event on Wednesday the 14th coming up, so people can still sign up and they will get access until that day to watch the film, I believe.

Sam: Yes.

Margaret: And then they can attend the webinar [Wednesday Oct. 14] that we’re going to have with yourself and Doug Tallamy and a number of other caterpillar experts that I’m going to moderate, and that will be recorded—so if they can’t attend live, they should still register, and get a chance to quickly watch the film while it’s available. But then it’s also available if people have a garden club or a book group or a who knows what—anything, a group of friends—they can license the film, they can access the film for a group showing?

Sam: Yeah. One day we hope the film will just be easily available to all, but right now it’s going around either through special events like Homegrown National Park set up with this current showing online, or it’s being shown locally at garden centers or nature show places. But it’s something, I mean, we’re pretty excited about it. It really captured the heart and soul of the Lab. Jeff McKay did a great job telling the story of caterpillars and what we do here, and we do hope that everybody will get to see it eventually. And for now, the great opportunity is through this Homegrown National Park platform and the panel that’s coming up.

Margaret: And yeah, I just think it’s going to be a fun conversation listening to all of you. And we’re going to be talking about different topics, I mean, life-history things and their role in the food webs and so forth, but also what they need to survive, their needs, their habitat needs, lots of different topics, I think.

Sam: Yeah. I mean, I think it should be a great conversation. I’m excited to see what it’s like to have our panelists in the room together. We’ll probably agree on a lot and maybe we’ll bicker a little bit, too, which should be fun [laughter].

Margaret: Oh, bickering, cool. I’ve never moderated a bicker.

Sam: Well, maybe if you ask us what’s the best caterpillar, we’ll probably have a little tiff.

Margaret: Well, it’s only you and me here right now, Sam, and I already told you I like the twig caterpillars, the geometrid ones, the best of all, because I was so blown away the first time I saw one. What is the best caterpillar? You have to tell us.

Sam: Oh, see, I shouldn’t put myself in that position. I mean, I like them all for different reasons, but I always love the caterpillars that surprise people that they never thought existed because that makes our job wonderful. People just get captivated by something they had no idea about. So the slug caterpillars are always high on my list, these things that look like tropical sea creatures that live in your yards.

But everybody who works here at The Caterpillar Lab has a different favorite. I’ve got Lucy in the background doing the wrangle today, taking care of the caterpillars, and she would immediately point to leaf miners and bark miners, these tiny little secret caterpillars that live in secret places eating individual cells. And those are just as surprising to people that there’s this whole world on that scale. So whatever the favorite caterpillar is, it’s just going to be one that captivates people’s imaginations and challenges them to think about the outside a little differently.

Margaret: Great. Well, Sam Jaffe of The Caterpillar Lab, I’m so glad to speak to you. Thank you for making time, and I’m looking forward to seeing you on Wednesday. And I can say, having watched the film, it’s wonderful and it shouldn’t be missed. Now you can go back outside [laughter].

Sam: Sure. Yeah, thanks for inviting me. And yeah, back to the swamps. Take care.

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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 17th year in March 2026. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the Oct. 12, 2026 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify (and browse my archive of podcasts here).