The Secret Lives of San Diego Zoo Insects

Many of us likely have childhood memories of a zoo visit: gibbons swinging above us, lions pacing, a polar bear taking a plunge. Zoos also can play an important role in conservation, particularly for insects. One example is the work done at the San Diego Zoo to help invertebrates by solving mysteries about their habitat and life cycle needs, in some cases bringing back species on the brink of extinction.

Joining us to talk about this work is Paige Howorth. Paige leads the Entomology Department at the San Diego Zoo, where she is involved with the day-to-day care of dozens of species of insects, arachnids, and other invertebrates in the zoo’s collection, as well as leading conservation programs for rare species. In addition, Paige serves on the steering committee of the Association of Zoos and Aquariums’ Terrestrial Invertebrate Taxon Advisory Group and co-leads the AZA SAFE (save animals from extinction) program for the North American monarch butterfly. She’s also been a collaborator with Xerces for many years.

Thank you for listening! For more information go to xerces.org/bugbanter.

Transcript

Rachel: Welcome to Bug Banter with the Xerces Society where we explore the world of invertebrates and discover how to help these extraordinary animals. If you want to support our work go to xerces.org/give.

Matthew: Hi, I'm Matthew Shepherd in Portland, Oregon.

Rachel: And I'm Rachel Dunham in Missoula, Montana.

Matthew: Many of us likely have childhood memories of a zoo visit: gibbons swinging above us, lions pacing, a polar bear taking a plunge. Zoos also can play an important role in conservation, particularly for insects. One example is the work done at the San Diego Zoo to help invertebrates by solving mysteries about their habitat and life cycle needs, in some cases bringing back species on the brink of extinction.

Matthew: Joining us today to talk about this work is Paige Howorth. Paige leads the entomology department at San Diego Zoo, where she is involved with the day-to-day care of dozens of species of insects, arachnids, and other invertebrates in the zoo’s collection, as well as leading conservation programs for rare species. In addition, Paige serves on the steering committee of the Association of Zoos and Aquariums’ Terrestrial Invertebrate Taxon Advisory Group and co-leads the AZA SAFE, which is “Save Animals From Extinction” program for the North American monarch butterfly. She’s also been a collaborator with Xerces for many years. So welcome to Bug Banter, Paige.

Paige: Thank you. I'm excited to be here. Thanks for having me.

Rachel: Yeah, it's so good to have you here. So I've always loved animals. And as a kid, my parents would take us—my brother and I—to our local zoo and our local aquarium. And I dreamed of seeing these animals in the wild. And I think that's part of why I became a wildlife biologist and chose biology as a career, because of that exposure to animals that I wouldn't have seen otherwise.

Rachel: I've not had the opportunity to visit the San Diego Zoo, but I was doing some research and there is an area called the Wildlife Explorers Basecamp, which includes the Spineless Marvels Invertebrate House, which just sounds so interesting. I imagine it exposes kids and adults to insects they might not experience otherwise. Can you tell us a little bit about this space and what someone might experience if they were to visit?

Paige: Well, I think, like, your experience is pretty typical. Everyone associates these big mammal species with zoos and everyone has these experiences, less so with insects. So for our new experience—it actually, it's new, it's still new to us, but it opened in 2022—we really wanted to lean into this concept of emotional design. And what I mean by that is, you know, pandas are easy to love. We can all get behind the beauty and majesty of a lion. But not so much with cockroaches. We all have other things that we feel about cockroaches and that's a pretty common theme with people. There's a lot of, you know, baggage around insects. I don't have to tell you guys that. That's something that you know very well. But the idea of kind of coming at that through the way that we experience things for insects—it couldn't possibly be more important for another group of animals.

Paige: So you know, we want to create basically affect. We want things to be positive affect. And that is things like, you know, really comfortably lit places, symmetrical things, sweet flavors. You know, all these things that, like, if you're listening to this right now, you feel like, “Yeah, I get that,” right? And things that create negative affect are, you know, like interrogation lighting or, you know, for some people, it's really flat terrains, like deserts and things like that are things that make people have this visceral sense of fear. And so positive affect opens your mind up to possibilities and negative affect makes it narrow and focus, because you might need to protect yourself.

Paige: So for Spineless Marvels, one of the most important things was: what are the first things people are going to experience when they walk into this place? If we put a cockroach on the outside of the building, or a tarantula on the outside of the building to announce that this is where you might see those things, you're automatically going to get people just turning away, right? So we have a really cool moth on the outside of the building. When you walk in, the first thing you experience is the scent of like a meadow. So we have scents involved to kind of pull up that feeling of like, “Oh, I feel okay here.”

Paige: There's what we call the migration flyover. So there's a digital dome that plays these vignettes of migratory species like, you know, monarch butterflies, dragonflies. And it's set, you know, throughout the day. So we have a morning scene with dragonflies and we have butterflies at midday. So again, you're getting colors, you're getting scents, you feel pretty good about this. And the live insects that are on habitat in that space are, you know, really interesting, unusual insects like katydids, grasshoppers—things that like, most people are okay with, right? 

Paige: So that's kind of how we set the stage to get—just to get people comfortable enough to come in the door. And then the habitats themselves, we really put a lot of focus on, you know, having like a little tiny ecosystem just within those habitats. So naturally planted, when we can, so that people can get a sense of like, you know, this beautiful, verdant exhibit. “What's inside of it? I'm willing to look.” So all of Spineless Marvels is that way. And I think—you know, I should say that it's like Spineless Marvels 2.0 because we had a smaller version of this in the previous children's zoo, which was the kind of like base for the new experiences in Wildlife Explorers Basecamp. So you'll see that repeated throughout kind of the entire experiences. You know, it takes you a while to get to the cockroaches. Haha!

Rachel: I love that you just thought about so many different things—the multi-sensory experience and you've really thought about your audience, of trying to draw people in that may not already be like excited about bugs, about insects. I think that's so, so smart. Because you're right, like, it's not hard to sell whales and bears and these really majestic, beautiful creatures that are like fuzzy and we grew up loving. It's different with invertebrates. And yeah, we do know that very well. And you've thought about it so carefully. I just really need to go to San Diego now and go to this zoo and experience this. So a couple of follow-up questions. How many species of invertebrates do you care for?

Paige: Well, we have—. So we have Spineless Marvels, which is our on-view for the public. And that is a 7,500 square feet of invertebrates, which is really great. And then we also have the McKinney Family Invertebrate Propagation Center. A lovely family just, you know, that really like saw the vision—actually, you know, their family supported the first Spineless Marvels when it was a much smaller situation at about, you know, 1,200 square feet. So we also have a huge propagation facility, which I'm gesturing to because I'm sitting in it right now. And so, you know, I would say at any given time, we're working with probably between 60 to 70 different species of invertebrates. So insects, arachnids, myriapods, millipedes, we have some crustaceans. And it does change a bit. There is quite a dynamic sense here often, because we send things to, you know, other participating AZA institutions that have the same species. We have some programs to make sure that these species are remaining in managed care sustainably.

Rachel: Wow, that's a lot. Haha.

Paige: It's a lot. And my team is incredible. You know, it's a lot of different needs. We always say like, “Many legs, many needs.” You know, it's very dynamic here.

Rachel: Yeah, I can only imagine. Are there any that are particularly notable?

Paige: I mean, I think they're all notable. Haha.

Rachel: Good answer. Haha!

Paige: I think one of the things, though—one of the other things we tried to get at with the way that things are arranged in Spineless Marvels—. You know, there's this idea—and again, going back even to like, you know, how you're processing information based on affect, right? If you have a broader mindset, you know, say you've come in and you've seen, you know, the grasshoppers and you're willing to, “Okay, now I'm ready to see a cockroach and I might even be ready to hear why they're important,” you know. So you've got this space in your brain to allow for these higher-level thinking processes. Instead of just, like, completely, you know, clenching up. But also at that point, you're ready to hear how important insects are to life itself, right? 

Paige: So, you know, we try to— like for example, with stick insects, we have, you know, a fairly large group of populations of stick insects from all over the world. And so, downstairs in Spineless Marvels, there's a section where you're seeing them—you know, obviously they're famous for camouflage, and that's cool and that's, you know, a lovely thing to know, but, why? And it's because everything eats them, you know? And so, what is that—you know, what does that mean for the ecosystem? A lot of times people that don't like insects don't realize that all the animals that they do like eat insects and wouldn't exist without them. 

Paige: So we really try to illuminate that wherever possible for people. And stick insects are one way of doing that. We certainly have some really cool species from Australia—the Goliath stick insects—which are, you know, these huge green and with like hot pink hind wings, and really spiky legs. We have some that are aposematic—so they're displaying that they don't taste good, they're red and black—from Peru. So just this huge diversity, you know. Leaf insects that look exactly like a kind of dried out leaf. And so we try to have ways for people to engage with that, including digitally. We have this huge kind of panel where you can pick out the stick insects that are camouflaging. And kids have such a great time doing that because, you know, it's kind of a fun game for them, but they also learn that these are really hard to find for a reason.

Matthew: Yeah, that's just amazing. I love the diversity of insects. I was going to ask: how do you choose the insects or the other invertebrates that would be in the zoo's collection? I mean, do you have criteria relating to the ease of care, for example, or maybe cuteness or—since insects appear alien to many people—kind of bizarreness?

Paige: Yeah, I mean, there's a little of all that. So we have, you know, hissing cockroaches. Everybody knows hissing cockroaches. And they are kind of like the fear factor aspect. But then we also have this beautiful little cockroach from India, called a domino cockroach, and it's a beetle mimic and it's just lovely. I mean, it's a little black cockroach with little white spots. And so, you know, there is some of that, where it's like, “Ah! This is gross.” And, you know, we love to have that too, because I think it's fun to make those comparisons. 

Paige: But a lot of times we're working with animals and we want to make sure we're working with them sustainably. So we have a lot of relationships with other zoos and aquariums. We have some programs to—like I said earlier, I think—to make sure that, you know, hey, if I'm working with, you know, weaving lady katydids, I want to make sure that if I'm experiencing some trouble with husbandry or maybe our eggs didn't hatch, you know, we want to make sure that there's somewhere to go for that within our own community. And so we really are, you know, checking in with each other frequently. 

Paige: So there's that aspect of it. And then there's also confiscations. We receive quite a few arachnid confiscations from either Border Patrol or U.S. Fish and Wildlife Service. Sometimes it's a sting where they're trying to stop someone from smuggling and they have to order some tarantulas from them, for example. So we've received large numbers of these different species. Because we have a sizable facility and we're close to a hub, we will often take in, you know, the whole thing and then we'll try to find homes for them within AZA institutions. 

Paige: I mean, there's also, you know, federal programs that need our help because this is what we do all day long is, you know, insect husbandry or, you know, invertebrate husbandry. And so, if there are species that are imperiled locally, that's something that that kind of comes into our purview.

Matthew: That's great. And with all of the habitats within the visitor area, do you swap out those at times? I mean, do you kind of have a turnover seasonally or whatever of different species that people could see in the area?

Paige: Yeah, we definitely do. If you think about insect life cycles, you know, often, like, we have several species of beetles that we're breeding at any given moment. And depending on the species, some of the larger dynastine scarab beetles—like Atlas[KS14]  beetles or elephant beetles, things like that—you know, they're larvae for two or three years. So nobody gets to see them when they're larvae. And then when they emerge—we don't really have a lot of control over when they emerge, either, as adults. So you know, it'll be like, “Hey, the Megasoma mars have emerged!” and “Let's put them on habitat.” And so maybe a praying mantis will have to come off habitat for a few months so that we can have that. So that's what's cool about it, is there can always be a surprise. You could come into Spineless Marvels every month and you might see something different than you saw, you know, the month before.

Matthew: And with all of that, do you have any that are more popular with visitors?

Paige: The Hymenoptera. The leafcutter ants and the honey bees. And we have a really large kind of pollinator section on the upper level of Spineless Marvels. And we engage people—again, we're trying to leverage senses—and so when you look down the room, you see this huge honeycomb. So you see this life-size, for us, honeycomb setup. And we have two honey bee habitats, or honey bee hives, set up in there that people can look at. And we do that, and then at the same time when you're coming in, you know, you can smell honey. Like, that's happening as you enter that space.

Paige: And honey bees are not the bee that we want everyone to focus on. But we know that they do. And so we want to be there for them. We want to be like, “This is an incredible species.” It's not native. And it's certainly, you know, even invasive in some areas of San Diego County. And so, you know, we want to start with the bee that they know.

Paige: And so, we have the setup for honey bees where we have screens that show them coming and going, foraging. And then we can raise those screens when we do hive inspections and interact with people while we're doing the hive inspection. So they can see right through the glass, they can see us in our bee suits and, you know, showing them the comb, showing them the queen when we have her. But then to the left, there's a huge mural of native bees and their habitats. And it's a really cool space because you're like, “Hey, there's this bee that we know and that's pretty cool. And I just learned that they're not native. And now I'm looking over here at this who's who of North American bees that are solitary bees, like most bees, and have all these really incredibly important roles.”

Paige: It's a hybrid. It's an agreement, you know, to kind of like, “Okay, this is the one I know and understand to a larger extent.” And now you get to learn about carpenter bees or cuckoo bees, you know.

Matthew: Yeah, we often think of the honey bee as a kind of the gateway.

Paige: Yep. Exactly.

Matthew: It's the one that people—the one that they know, the one they have positive ideas about. And so once they get that, then it’s leading them on into discovering everything else that's out there. That's the trick. And you're able to do that, so you must have education programs associated with the Spineless Marvels as well, I'm guessing?

Paige: Yes, we do. Well, we have an incredible education department and lots and lots and lots of programs. There’s summer camp all summer long, where kids are engaging with different parts of the zoo. And then there are several like school programs throughout the year. There's a lot of grant funded work that goes on within our education department. And I think we decided that, you know, about—organization-wide—about 33,000 kids hear about insects every year, all throughout the year. So that's pretty great. Obviously not just insects, but while they're part of this experience.

Matthew: Yeah, it's pretty immersive interaction with them, too, from what I see.

Rachel: That's amazing. So I love that you have all these education programs and you're really focused on inspiring people and getting them to care about these insects. But it doesn't stop there. You also do a lot of invertebrate research and conservation work. Can you tell us a little bit about this?

Paige: Yeah, so again, we kind of—. We’re there if there's a need. And one of our programs is the Lord Howe Island stick insect. And I would say—. If I had to say, “What's the most famous insect?” That would be the one. Most people that know something about insects have heard about that one. And just as a brief background for people who are listening, this is a big black stick insect. It's found within the —or was previously found within the Lord Howe Island group, which is like an island chain off the coast of Australia. It is endemic to Lord Howe Island and it's one of those things where, you know, endemism is a really prominent feature, and it's a world heritage site. So it's just this incredible ecosystem.

Paige: And in 1918, a trade ship ran aground on Lord Howe Island. And there were rats on that ship and the rats all unloaded onto the island. And by 1930, the Lord Howe Island stick insect was extinct along with 13 other species of invertebrates. So it's a very typical story for invasive species. But, you know, at that point, it was declared extinct. And then in the 1960s, some climbers who were climbing Ball's Pyramid, which is this like volcanic spires sticking out of the ocean still within the Lord Howe Island group. But it's, you know, basically uninhabitable. It has no sort of flat spaces. And they had said that they had seen stick insects up there, that they had seen stick insects resembling Lord Howe Island stick insects. 

Paige: And so in the ensuing years, there were a lot of petitions to get permits to climb Ball's Pyramid based on that information. And finally, the Department of Environment in Australia basically said, “We need to just go up there and figure out if this is actually a thing.” So in 2001, they sent a small expedition up to Ball's Pyramid, which sounds like it would be easy but, you know, you have to wait for the right conditions. You basically get tossed onto the shore. You have to kind of grapple your way up with ropes and climbing gear. It's an extremely inhospitable environment. And they had to do this at night to try to find the stick insect. And they found a small group of these stick insects in 2001. So it was rediscovered after all that time. It was back on the map.

Paige: So it took a couple of years and in 2003 they brought down four individuals to participate in a captive breeding program. And ever since then, Melbourne has been working towards the recovery of this species. And in 2012 we joined that effort to have an assurance population here in San Diego, just in case something happened elsewhere. So that's one of our focal species.

Paige: And then we also work on imperiled butterflies in San Diego County. So, Quino checkerspot butterfly, the Laguna Mountains skipper. We're starting to work on a species called the Harbison's dun skipper, as well. This is a biodiversity hotspot—San Diego County—so there's a lot at stake, and unfortunately a lot of need as well.

Rachel: You mentioned that you obviously work with some external partners, and I'm assuming it depends on the situation and the species. Do you have any specific partners that you work with more frequently? Obviously, you're not doing this work just siloed within the zoo.

Paige: Yeah, absolutely. So Zoos Victoria Melbourne Zoo has been just a really close partner ever since the beginning of the program for us. We also work with the Lord Howe Island Board, which manages all the activities on the island. We work really closely with U.S. Fish and Wildlife Service, California Department of Fish and Wildlife. We have a lot of great local partners, as well. The San Diego County RCD—Resource Conservation District. We work with the city. We work with the county. So there's just so many moving parts when you're—especially for the local butterfly programs, you know. We have a partnership with the Forest Service for the Laguna Mountains skipper, because of where they're found.

Matthew: Yeah, these things almost always are a collaboration. I don't remember the last time I came across a situation where someone said, “Yeah, I did that.” And it really was just them. Haha.

Paige: Yeah, “I did it all by myself.” Haha. Yeah, that's rare.

Matthew: You were telling us about the incredible story of the Lord Howe Island stick insect. Another fairly unusual insect, a species that you have there—it's a dragon-headed katydid that I know you were also doing some work on. Did you have challenges in caring for them? You know, because these are —as you say, there were like 20 of these stick insects up a rock in the middle of an ocean. So how did you figure out how what kind of care they needed or the sort of breeding needs?

Paige: Yeah, I mean, I—. If you think about how many insects there are in the world and how many insects there probably are in the world. The number is like — it could be huge. Millions and millions, right? And then you think about how like mammals—. I mean just—. Like we know what tigers eat. We know what lions eat, right? You know, there's always room to grow with those species, but it's not like the basics haven't been worked out. And that's not the case for insects or other invertebrates. So there's so much experimentation that goes on. We call it tinkering. Because it's just such a huge and fun challenge.

Paige: And so, like in in the case of the Lord Howe Island stick insects, you know, Melbourne Zoo had been working through host plants for them because that, you know, that's all they eat is—. You know, on Ball's Pyramid, there's melaleuca bushes growing along the side of the cliffs and that's what they feed on. And so, you know, we have this idea of what they might eat because we know the plants that are on Lord Howe Island. However, most of those plants are not available to us in the United States, at least at the time that we first started our part of the program.

Paige: You know, there's a big difference between—. I mean, even the influences in the plant itself, the soil chemistry, the age of the leaf, you know, all these different things come into play. There are plants that Lord Howe Island stick insects definitely eat, but they cannot eat when they're young because their mouthparts are not strong enough. So it's just this whole spectrum of variables and you—. When you're starting out with a program like that, you want to make sure you have, “Okay, we have at least, you know, these plants that we know work over there.” And the outcome for us has been that it's been really different for us. We actually, in 2013, one of our horticulturists actually flew to Australia to gather seed and cuttings of some of the plants that we couldn't get here at the time. And those are now well established here. But again, this is like things that have taken, you know, years to put together.

Paige: Things like that are—. I mean, that's kind of an extreme example. “Oh, we had to go to Australia to get what we needed.” But with a lot of the insects that we get, you know, we have some you can't just—. Even a Google search is sometimes like, “Yep, it exists.” And there's just nothing, you know. So you have to kind of start at the beginning and often that's like evaluating the insect. “Okay, you know, it has this kind of mouth part, so we know that it's going to eat these kinds of foods, theoretically.” And then try things and then hone those things.

Paige: And for the dragon-headed katydid, that was the case. Because they have these huge, you know, fearsome mandibles. And you're like, “What are they doing with those mandibles?” Because we would put live insects in there and they would recoil from them. We gave them nuts. Sometimes they would eat seeds. But it was— you know, it took a long time to get to the point where we had a pretty good grip on their diet. And it turns out that they use those mandibles to chew holes in these large plant stems so that the females can lay their eggs inside of the plant stems. But, you know, they can't tell us that, so—. That's the fun part and the kind of like "Ah!" challenging part of it.

Matthew: And I imagine one of the challenges is that you've got these live insects and you're trying to work out what they'll eat. And although you can do all this thinking in advance, until you actually have them and are putting that in front of them, you don't know for sure.

Paige: Yeah, that's why we have this, like, other like, “Oh, it's a kitchen sink diet.” Just like, “Here are all the things, you know. What are you going to choose?” And then try to work on it from there, so—. 

Matthew: It's not like a teenager. You can't just open the fridge and let them go, can you?

Paige: Exactly.

Rachel: So you've mentioned a few butterflies that you have worked with that are local and some of those are federally listed as endangered. Can you tell us a little bit more about these butterflies, and did you have any similar challenges with them? Or did you know more because they're local and maybe you can go out and observe them?

Paige: No, no. Haha.

Paige: I mean, some of them, yes. Some of them, yes. The first one that we worked with—the Quino checkerspot butterfly—it's a beautiful little nymphalid butterfly. It has kind of an orange, and red, and black, and white pattern on its wings. It was listed as endangered in 1997. And the recovery plan called for, you know, rearing, laboratory rearing of some kind, to augment populations. And we got involved with that in—also in 2012 but we were in a drought cycle and there were not enough butterflies in San Diego County to justify collecting any for the head-starting program. And head-starting is really collecting females that we think have eggs, and bringing them into the lab and encouraging them to lay those eggs, and then rearing those larvae and releasing them.

Paige: So, it wasn't until 2016 that we actually were able to collect our first cohort of founders for this project. And it was really successful. And so, one of the things, for Quino, that's so interesting is that, you know, they have this period of obligate diapause where they have to just shut down. And that happens in the summer. And I think diapause for—. For people listening to this podcast, they probably know what diapause is, but just in case. For insects, if you think about, like—I always say the poster child for insect diapause is the monarch butterfly. And the adult monarchs are in diapause when they're in the trees. They are not extending a lot of energy. They're not, you know, reproductively active.

Paige: So for Quino checkerspot butterflies, this is happening in the larval stage. And they basically molt into this kind of fuzzier, sturdier version of themselves as larvae and shut down for several months until it starts to rain in San Diego County. One of the things about them that makes that challenging is, you know, for—. If you're rearing insects and you're like, “Okay, we're going to rear them. And then we're going to release them. And what is the life stage that we're going to release them?” Well, you know, you have choices. You have larvae, pupae, adults. But for Quino, it seems better—since insects are so much closer to all these inputs that they're receiving: the chemicals in their environment, these triggers of rain, and their host plant germinating—it seems better for them rather than to keep them in the lab and have them come out of diapause in the lab, feed them, and put them out. It seemed better to put them into the habitat while they were in diapause so they could experience those cues naturally and respond to them in a way that's completely organic.

Paige: So that's what we ended up doing with Quino. And we've had a lot of success. I think we've reared and released more than 16,000 Quino checkerspot butterfly larvae into historical habitat in San Diego County. And again, there's so many parts to the life cycle that something like that didn't actually—wasn't the best choice for the skipper, right? So each insect is completely unique and needs to be looked at in that way.

Rachel: Wow, that is a lot of butterflies and so interesting how much you learned.

Paige: We learned a lot, and we learned—. We were able to confirm things because of the way that we released them that were suspected but hadn't been, you know, 100%—. You just couldn't confirm them, because if you're out in the wild and you're like, “Yes, they go into diapause and we know that. But how many years can they stay in diapause? Or can they come out of diapause and go back into diapause?” And the answer is, “Yes,” and “Yes.” 

Paige: We release them in these vessels that allowed them to escape the vessel whenever they, you know, emerge from diapause, but also camouflage them in the environment. But during the summer, when they were in diapause, it also allowed us to check them. So we put them out and whoever emerged, emerged. We could count how many emerged. We could confirm over time that they were staying in diapause more than one season, which is crazy because they're like six millimeters long. So it's allowed us to learn a lot more about the animal just from the way that we release them. And hopefully that's going to—you know, that's always helping us to kind of adapt the new strategies for the next season, so.

Matthew: I hope you don't—. I'm going to jump in with a random question here. You said, “vessel.” That you had them in this vessel. I'm just wondering, I mean, I've seen some kind of rearing operations where, you know, the vessels is a little plastic cup. But I can't imagine that you're putting plastic cups out with the larvae in each. 

Paige: No, definitely not.

Matthew: They would just overheat, wouldn't they? So anyway, I mean, I was just wondering what those vessels were, really?

Paige: So when we were thinking about this, I mean, we were really just spit balling. And again, that's like the mad scientist laboratory of, like, you know, “We could do anything. Which should it be?” We ended up buying finch seed feeders. They’re mesh, so they're large enough openings for these tiny larvae to come out of on their own. And the larvae in the lab, we give them kind of twisted up shop towels. So we take a little square—maybe like a two-by-two square of really sturdy paper towel—and we just twist one corner of it. And when they're ready to go into diapause in the lab, they start to array inside of the folds of the bugles—we call them bugles. There's a name for everything. Haha.

Paige: And so when they go inside the bugles, they web up and molt and then they shut down. And we can tell that that's happening in the lab because we stop seeing their frass on the bottom of the cup, so we know that they're not feeding anymore. They back off feeding. We're giving them less and less host plant.

Paige: So then, we take those bugles and we put them inside of these peat pots. And the peat pots are used for planting. They’re, you know, maybe like three inches tall, and they're basically paper and biodegradable. And we poke big holes in those. So we put the bugles inside of the peat pots, and we put the peat pots inside of the seed pods, which have been painted “Chaparral Brown” to camouflage in the habitat. And then when we're ready to do the releases, we do them kind of before it starts raining. We wire them to shrubs in the habitat, and then we GPS the location. And then we can go back and evaluate them after the actual flight season has happened.

Matthew: Yeah, that just seems like a detail that probably most people aren't thinking about, you know. You can release—. We've probably all seen videos of someone releasing an eagle, or someone releasing something else, and they just, you know, they take the pet carrier out, open the door, and off it goes.

Paige: That's right. Yeah, we warned—. We did—. We had media for a couple of the releases and we warned them ahead of time. “Nothing's going to happen.” Haha.

Matthew: “Watch me wire this to a shrub.” Haha.

Paige: Yes, exactly.

Matthew:There are so many different species in the collections that you manage and care for them. And do you have, like, your favorite, or any that you're particularly fond of, or especially enjoy?

Paige: I have always been a fan of leafcutter ants and, they're just—. Ants in general, I'm a fan of ants. It was really amazing for us to do ants the way we did in Spineless Marvels, because everyone I think is familiar with leafcutter ants, you know. If you've been to, you know, the neotropics, you've probably stepped over them because they are not worried about being in your way as they're foraging and they're carrying their leaves. But it's difficult to tell that story, you know, away from where you would normally encounter them. And even then, you're only seeing the workers and the foraging aspects of that colony. And what's happening underground is so incredible, you know.

Paige: So we have kind of both sides of that at our habitat. It's neat because people can see them foraging. They can follow them inside. And again, when they're coming inside the habitat, the first thing they hear is this very pleasant meditation music. So it's like, “Oh, it's dark in here, but I feel good about this,” you know? Haha. And within that track, we layered in, you know, ant stridulations. So when they're rubbing two parts of their bodies together to communicate. There's a little bit of ant stridulation in that track. There's a little bit of leaf rustling, but mostly it's meditative. And then you're there, and then you're experiencing the subterranean nests and seeing that these ants use those leaves to feed a fungus that they cultivate. And the fungus is actually what they feed to their young. It's this incredible, incredible ecosystem, superorganism.

Matthew: And just thinking about this. Leafcutters, do they need particular species of leaf to cut? Just knowing that they're growing the fungus, I don't know whether—you know, can you grow a fungus on any old leaf or do you need something in particular?

Paige: You can't. I mean, they have a pretty good breadth of species that they will cut, but it's the fungus that's signaling the ants. “No more of that. No more of that. I don't want that.” So they have to switch it up. So our team, when they're providing that for them, you know, there'll be like three days of using Cape honeysuckle. And then on the fourth day, maybe they're just not cutting it as much and you have to switch it up. So there's a constant dynamism, too, to the things that are being offered. I mean, luckily we're in Southern California. We have—you know, we're really lucky to have an organic garden right next to the invertebrate propagation center, so that we can give them a lot of choices. 

Paige: But yeah, it's really interesting to watch them. And people can see them. They can see the fungus, they can see the ants working the new leaves into the fungus. And we have it magnified on a TV screen, as well, so you can see all the features of the ants that are really adapted to doing this. They have a little groove on their head so that the leaf sits right there. And just the idea that they're just greater than some of their parts is so fascinating. So yeah, leafcutter ants have been at the top of my list for a long time.

Matthew: Yeah, understandably. I mean, there's so many fascinating insects, but when you see them like that. And behaving in ways that people don't expect an insect to behave. Because, as you say, they're basically fungus farmers, so—.

Paige: Yeah, exactly.

Rachel: Oh, that's so cool. I really like leafcutter ants, as well. I've been able to see them in Costa Rica a few times and I just kept thinking of this one moment my husband and I were watching some howler monkeys and I looked down and noticed leafcutter ants and, you know, they have this like giant line where they're assembling and taking their leaves off. And I was like trying to tell the other people, I'm like, “Don't step on the ants!”. And I'm like, “Look how cool they are!” Pretty sure everybody thought I had lost my mind, but I felt good about it. Haha. I was like, “People need to realize how cool these ants are.” Like, I get mammals. They're very cool. I love them, too. But I just love how you've described the exhibits and the experience that people have in this insect house. So thank you for all the work that you're doing. I think it's just so incredibly important—inspiring hopefully adults as well as kids and creating future entomologists.

Paige: Yes. Well, that's what we hope. I have such a great team and we all work together to light people up about insects, so—.

Rachel: Yeah, definitely. Well, we're going to ask you what our favorite question is—we ask everybody that comes on our podcast. But what inspired you to work in entomology and at a zoo? I'm very interested to hear your answer for this.

Paige: Actually, I was pre-med in college and I happened to take zoology from an entomologist. And it was like over after that. It was just—. She was so excited about it. And it exposed me to them in a way that I—. I mean, because I grew up around insects. I grew up in the Midwest. I mean, I miss the fireflies, and the goatweed emperors, and, you know, all the insects that were just part of my childhood. You know, something about her style and her passion really, really caused me to take a second look. And I never looked back, right? So I think that's a testament to, you know, meeting someone that's excited about insects, and your brain opening to that, and being willing to say, “Well, I don't like cockroaches, but I'm willing to hear what you have to say.” So yeah, that's my story.

Paige: And as far as a zoo, it was actually almost incidental. Because I didn't really grow up going to the zoo because we lived kind of on the outskirts and we had, you know, like 18 acres and horses, and stuff like that. And so that was my—. I was like, “It's zoo-ish already,” right? Like, we didn't have a big connection to our zoo. But it was that mentor that kind of told me, “You know, this is—there's some cool stuff happening at zoos. There's some cool stuff for insects. You should check it out.” I think it's worked out. I'm very happy. I love that San Diego Zoo, you know, understands the importance of people's awareness of invertebrates. And if we can do something to raise that awareness, you know, I think, I'm grateful to be here to do that.

Matthew: That's great. Thank you.

Rachel: I love that story. And I'm so grateful that you came on our podcast. I hope you've had a good time, but I have certainly learned so much and I definitely—I'm going to plan a trip to San Diego now because I want to visit the zoo.

Paige: You should. Yes, absolutely.

Rachel: It sounds amazing.

Paige: I’d love to take you through it. Well, thank you for having me. It was so fun to talk to you both.

Matthew: Yeah, of course. Thank you.

Rachel: Thank you so much. 

Matthew: Bug Banter is brought to you by the Xerces Society, a donor-supported nonprofit that is working to protect insects and other invertebrates—the life that sustains us. 

Matthew: If you’re already a donor, thank you so much. If you want to support our work go to xerces.org/donate. For information about this podcast and show notes go to xerces.org/bugbanter.