Wings of the East: Exploring Butterfly Life Histories

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Guest Information

We are joined by Ray Moranz, who you may remember from episode six, when he talked about the monarch, a butterfly that can be found east (and west) of the Rockies. Ray is a pollinator conservation specialist and NRCS partner biologist with the Xerces Society, and has spent many years studying butterfly and plant communities across the US.

Show Notes & Links

In this episode, we explored the life histories of butterflies east of the Rockies. We discuss what is impacting their populations and specific tips for plants throughout this wide region.

• Pollinator Resource Center

Transcript

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

Matthew: Hello, I'm Matthew Shepard in Portland, Oregon.

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

Matthew: We're continuing with our series on butterflies, and today we are highlighting the butterflies east of the Rockies, which is a huge area and encompasses so many different environments — prairies in the Great Plains and the Midwest; forests of New England and the Southeast; mountains of the Appalachians; the wetlands and beaches of the Atlantic and the Gulf coasts.

Matthew: To try and cover all of these, we are joined today by Ray Moranz, who you may remember from episode six, when he talked about the monarch, a butterfly that could be found in any of those areas. Ray is a pollinator conservation specialist and NRCS partner biologist with the Xerces Society, and has spent many years studying butterfly and plant communities across the US.

Matthew: Welcome back, Ray.

Ray: Great to be here, Matthew. Great to see you, Rachel.

Rachel: It's great to have you. So, to lay the foundation, what are we talking about when we say east of the Rockies, first of all, and then, can you give us a sense of the diversity of butterflies that you can find in that region?

Ray: Sure. Well, we're talking about everything from Texas, Eastern Colorado, Eastern Montana, etc, the Great Plains, the High Plains, all the way over to the Atlantic coast. We're focusing on the US today, but some of what we talk about will be relevant to Ontario and Quebec as well. But yeah, highlighting the Central and the Eastern US, going all the way, almost to Denver, but not quite.

Ray: And you asked about diversity. Diversity of butterflies in this region is pretty high. It's a lot lower than the Amazon, but the Amazon based in the South Americas has the highest diversity of butterflies in the world. Nobody can quite compete, or compare with that. On the other hand, I think, I'm pretty sure it's the case that my county in Oklahoma or any county of Oklahoma has more species of butterflies than all of the United Kingdom put together.

Ray: So yes, our butterfly species richness in Central and Eastern US is a good deal higher than many places in Europe. And, we've got plenty of great butterflies to be proud of, and to search for.

Matthew: So, sorry to jump in, you mentioned the United Kingdom, you know, most of my heart, home country and all that.

Ray: Yes. Sorry, Matthew.

Matthew: Yeah. So no, that's fine. I just can say, because I don't know how many people know how many species there are in that country, and it's 59 or 60. It used to be 59 and now I think it's 60. So that was just to give people a kind of a baseline, you know. So, your county in Oklahoma has more than 60 species.

Ray: Yes, I knew it was low in the United Kingdom. I thought it was higher than that. Oh, my good gosh. And yes, of course the British have been butterfly enthusiasts for hundreds of years, and you know, incredible leaders in the field of butterfly research and all that but yes.

Ray: In Paine County, Oklahoma, where I live, I think we can see upwards of around 110 species of butterflies. Oklahoma as a whole, I think it's about I think between 160 and170 species of butterflies, in the state. If you count the things that only occasionally make it here, it is even higher.

Rachel: So, with the number of butterflies that are in the East, they must vary a lot. Can you tell us what the biggest and the smallest species is?

Ray: I can and I've seen them both. The biggest is the giant swallowtail. And the name says it all. It's a swallowtail. One of those butterflies that's got long skinny tails like the barn swallow, the bird, and it is colossal, and I do have those on my farm. A beautiful species. Primarily black and yellow.

Ray: At the other end of the scale, we have an interesting contest for the smallest butterfly, east of the Rockies. If you had asked what is the smallest butterfly of the Eastern United States 30 years ago, the answer would have been the eastern pygmy blue. Very, very tiny little butterfly. The smallest.

Ray: But there's a butterfly even smaller than that in the Central and Western United States, the western pygmy blue. So, the answer is the western pygmy blue. And a very interesting thing is that now the western pygmy blue, which was only in the West and in the center, has moved to the East.

Ray: They've just colonized Tampa Bay in Florida. So, now the eastern pygmy blue loses its distinction as the smallest butterfly of the East. The western pygmy blue has arrived and has beaten it out for being even smaller.

Mathew: And all the way from like the western states to Tampa Bay. Is there nothing, no records in between?

Ray: Okay, we have them here in Oklahoma. They're in Texas as well, so they didn't have to go all the way from LA or San Diego.

Matthew: And do they compete directly with the eastern pygmy?

Ray: That's a great question. I actually do not know. I do not know the host plants of the two species, but that's probably where the competition would be.

Matthew: And they're not like fighting.

Ray: That's right. That's right. Yeah. Yeah.

Rachel: Little butterfly fights.

Rachel: So, east of the Rockies is a big and diverse region. As Matthew mentioned in the description, it’s got a lot of different types of ecosystems. Does butterfly diversity vary across the eastern US?

Ray: Absolutely. I think in general diversity is a little bit higher in the South than in the North. There is one very clear hot spot of butterfly biodiversity east of the Rockies and that is South Texas. So, Texas already was going to be a hot spot. Because of its longitude, it's getting some butterflies from the East, that just barely make it into the center.

Ray: It's got butterflies that are primarily in the Central US, and it gets a few butterflies from the West. But then, you go to down to South Texas and that's where things get really special. You get a whole bunch of species that are basically Mexican species. And just barely cross the Rio Grande into South Texas.

Ray: And these are some really exotic tropical beautiful creatures. So, there is a national butterfly center right on the American side of the Rio Grande River, and I've been there once and it was a delightful experience. And at that national butterfly center, people make a pilgrimage there to see butterflies that they can only see in South Texas and nowhere else in the United States. So, that is the ultimate hot spot for butterfly species richness in the lower 48 states.

Matthew: Sounds like a pretty cool place to go.

Ray: It is, it is. It's actually a very hot place to go.

Matthew: Hot but cool. Yeah, I mean, I know in previous episodes we've heard about how plant diversity is often an indicator of butterfly diversity because of like the close relationship with host plants and so on. I mean something that's the same sort of in the Eastern US as well that you know that the presence of the right kind of plants helps drive the butterfly fauna.

Ray: Yes, that is a factor and the Southern US does have higher plant species richness than the Northern US with the big hotspots of plant biodiversity being the Florida Panhandle, where I used to work. Totally amazing for plant diversity, lots of rare endemic plants. Chesapeake Bay area has very high plant diversity and then, portions of Texas.

Ray: But, the Florida Panhandle is not, you know, though it's a great hot spot of plant biodiversity, it is not a great hot spot of butterfly species richness. It's got some great butterflies, but the butterflies species richness does not match the high plant species richness. Interesting.

Ray: So, in the East, it's not quite that simple. It's not quite that simple as saying there's a really strong positive correlation between plant species richness and butterfly species richness.

Rachel: Do you know why that is in Florida? Because I was shocked when you said Southern Texas was kind of the main hot spot. I was like, wait, what about Florida? Cause you think tropical weather, lots of plant diversity.

Ray: I think the thing that Florida has going against it is that it's a peninsula. So yeah, the peninsula effect reduces the amount—there are a whole bunch of cool butterflies in Cuba and Jamaica and, Puerto Rico and Dominican Republic and Haiti. That weren't able to cross the water up into Florida as opposed to butterflies from North Mexico that are able to cross the Rio Grande into South Texas.

Rachel: That makes sense.

Matthew: Yeah, that makes sense because it's much easier for a butterfly to fly a short distance.

Ray: That's right.

Matthew: I mean, the monarch, obviously, can fly huge distances. But most of the butterflies can't.

Ray: That's true.

Rachel: Are there any unique species found in the East and nowhere else?

Ray: Unique species. Sure. A whole bunch. Oh the Diana fritillary, that's a really obvious example. The Diana fritillary is a colossal, beautifully colorful, butterfly of forests of the Ozarks and the Appalachians.

Ray: And it does seem to be moving west. Which is fascinating to me, but, by just a few miles. It used to only be in far Eastern Oklahoma. And now people are occasionally seeing them in Central Oklahoma where I live. But yeah, there's a whole bunch of species that are only in the East and not in the West. And vice versa of course.

Rachel: Are there any butterflies with notable life histories?

Ray: Oh yeah. I mentioned the Diana fritillary a moment ago. Now I'm going to talk about one of its sibling species and that is the regal fritillary. And I have been a big fan of the regal fritillary butterfly ever since I heard about it in the nineties.

Ray: And I ended up getting my PhD studying the regal fritillary. The regal fritillary is a large, very colorful butterfly with orange, black and white and purple, silver. Quite an attractive species. And it is non-migratory, which is important to note, but what makes one of the most unusual things about it is that it estivates. The females of that species, estivate.

Ray: Now, estivate is like hibernate, but in the summer. So, there are many butterfly species that hibernate. They spend the winter inactive in very cool places. And the regal fritillary does that. But it's female estivates.

Ray: The female comes out of the chrysalis. Let's say June, early July. It mates, and then rather than going out and laying eggs, which is what most butterflies would do. It disappears. Where does it disappear to?

Ray: It goes down into the grass and just hides, and just waits and sits and waits through much of July and August, and early September, and then let's say September 10th, mid-September, late-September, they come out, and they lay eggs.

Ray: That's really weird. That's really unusual. The other thing that's unusual about their egg laying is how many they lay. 3,000 eggs per female on average.

Ray: A female monarch lays a lot of eggs. She lays 300, a regal fritillary lays 3,000. 3,000. Supposedly, from what I've read years ago, more eggs than any other butterfly species in the world.

Ray: Why do they lay so many eggs you might be wondering? Because they also have the unusual strategy of laying them at random. Now, I don't mean completely at random. I don't mean like they'll lay them in your backyard and in a grocery store parking lot, in the forest and at a lake.

Ray: They're restricted to prairie, usually very high quality, tall grass prairie or mixed grass prairie. But once they're in the proper habitat, prairie with violets, because that's the host plant for their caterpillars, they don't lay them on the host plant. They lay them near the host plant. Sort of. Just out and about in the prairie.

Ray: And then it's the job of the little caterpillar, an extremely tiny caterpillar that comes out of the egg, it's the job of the caterpillar to find the host plant. Sometimes they might have to crawl 10, 20, 30 feet to find a host plant. You could imagine that a lot of those caterpillars will fail to find the host plan. Therefore, the female has to lay a lot of eggs. It's a strange custom, strange behavior.

Ray: You know, as we know, monarchs lay them right on the plant. Most butterflies lay their eggs right on the host plants, but not the regal fritillary, she's got to be different.

Matthew: So, the female fritillary, she’s just like flying around just dropping eggs.

Ray: Well, not dropping them, but I watched this and it was a real treat. She drops. She'll be hovering, flying very slowly above the prairie, maybe 3 foot off the ground. And then all of a sudden, she falls down near the ground, lays an egg on a blade of grass or on a shrub or what have you and then she gets up. And goes 10 or 20 or 30 feet and drops. Again, seemingly, traveling at random, leaving her eggs in the midst of the violets but not on the violets.

Matthew: I'm still thinking about this. I mean, it's a lot of effort to drop and lay an egg, but just sort of close-ish.

Ray: Yes, it is.

Matthew: I mean, I know violets are typically pretty short plants, low growing and this is tall grass prairie is it?

Ray: Yes.

Matthew: Yes. So, the violet plant must be difficult to see amongst the grass.

Ray: A lot of the time the violets are hidden under the grass if the grass hasn't been burned in years, the prairie hasn't been burned, they'll literally be underneath the litter, trapped in it, but the caterpillars can find it.

Matthew: Do we know how the caterpillars know which direction? Because you have to drop out of an egg and you look around and sniff. I mean, how do they know which direction to go in? Or is that because there's 3,000 and only 10 of them survive? You know?

Ray: I cannot answer that and in fact I have never seen a regal fritillary caterpillar. Never. In part because I’m in prairies with many, many violets and, it's really hard to find the caterpillars

Matthew: Yeah, because they'll be tiny.

Ray: Yeah. They're tiny and it's like looking for a needle in a haystack, but I do know people who have done research on the caterpillars. They've seen them and they might be able to answer that. But, I have no answer to that at this point.

Matthew: Yeah, no worries, I just had to ask.

Rachel: I think I understand why she rests for a few months before laying her eggs, between the number she's preparing to lay and then dropping.

Ray: Supposedly another reason why she would estivate, why she would hide in the middle of summer, is because the violets to some degree go dormant in the middle of summer when it's super, super hot.

Ray: You know, here in Oklahoma, a typical summer day is 105 degrees with low humidity. The violets don't like that, but then they come back up in the fall. So, the female, I think that's probably the main reason why they have evolved to have that behavior, is to avoid the horrible heat of a mid-summer in Oklahoma.

Rachel: So, this is the point in the podcast where we get down to population decline. Talking about how butterflies are doing. So, I heard about a study that they did in the state of Ohio and they found that the abundance of butterflies is in decline 2% per year. Which is a lot. Is that true for other states that you know of and are there any species of particular concern?

Ray: Well, certainly that Ohio study measure, is similar to a study out West by Matt Forrester and his team showing widespread declines in butterflies out West. I personally am not aware of other similar studies in the East, similar to the Ohio study. But yeah, the Ohio study is quite worrisome and the fact that this could be happening you know, my assumption is that this is happening regionwide.

Ray: That many, many states are suffering, in the Eastern and Central US, are suffering major declines in butterflies from year to year. And I looked at that paper and some of the species that are declining. One of them, the American copper, a beautiful little thing. That's one of the butterflies that got me to like butterflies when I was a little boy growing up outside of Rochester, New York.

Ray: I'm pretty certain I saw that beautiful little American copper in my backyard. Which is a sort of an average suburban lot, and to hear that it's declined very substantially really, really, really pains me.

Ray: Another butterfly that's declined quite a bit is the Baltimore. That's the butterfly I saw as an undergraduate in Ithaca, New York. But I haven't seen it since. Now I haven't lived in that part of the country in decades, but, I've heard other people report how the Baltimore butterfly has declined quite a bit.

Ray: So, it's very sad to see that corroborated by data from the Ohio study and of course monarchs. The Ohio study does show a decline in monarchs and many of us have seen that in our careers and it's painful to see.

Matthew: Yeah, if it is a 2% decline, then it takes 20 years, for a third of the butterflies to be gone.

Ray: That's right. That's right. Yeah, what about the next 20 or 40 years? What happens?

Rachel: So, we also talk about this often, on the show, but what's causing these declines and on the flip side of that, are there any stories of hope? Are there any species that are doing any better that are expanding numbers or moving to new areas? You've mentioned that a little bit.

Ray: Yeah, causes of decline first. You know, the one I always focus on most is habitat loss. You know, we keep on losing habitat through conversion of native ecosystems to cropland. Conversion of native ecosystems or semi-native ecosystems to urban and suburban development.

Ray: So, that's huge. Changes of land management are huge. I am a big proponent of prescribed fire. I conduct prescribed fire on the farm, the 10-acre farm that my wife and I live on here in Oklahoma.

Ray: And I know from experience that it helps improve habitat, but there are huge expanses of the Central and Eastern US that haven't had prescribed fire for you know, a long, long time. And they're getting choked with too many cedar trees or too many red maples back in the East. So basically, habitat conversion through poor management, it's a big problem.

Ray: Pesticides. Research by the Xerces Society and others are showing more and more evidence that pesticides are a factor, particularly insecticides, of course. So those are, to me, the biggest threats. And climate change has got to be having an impact as well.

Ray: Oddly enough, it's climate change that I can cite, which is probably causing some of the interesting increases of range by some butterflies and, one of the butterflies that I was fascinated to learn, that has expanded its range is the giant swallowtail. The largest butterfly in North America.

Ray: I learned this while I was preparing to deliver a webinar on the butterflies of Vermont. I've never seen a butterfly in Vermont. But I was happy to give the webinar anyway. It's a beautiful state. And it gave me a chance to learn about the butterflies of Vermont through some reading. And in my reading, I discovered that giant swallowtails now have colonized Vermont and now they've gotten into Canada.

Ray: And, part of this seems to be due to an expansion of their host plant northward, but also, probably just warmer temperatures are allowing the butterfly to survive further north.

Matthew: There's been this northward movement and range expansion. How far north were they previously recorded? I mean Vermont in the long way north, were they in New York or?

Ray: I believe they were. I never saw them. They're going up and I'm pretty sure yes, I think they've moved, but I think they've expanded the range about 200 miles.

Ray: Which is quite a bit. I mentioned earlier that Diana fritillary seems to be expanding its range westward, at least a little bit here in Oklahoma. Which is strange and hard to understand. And then there's a butterfly in Florida, which almost went extinct, the Florida atala butterfly.

Ray: People started planting its host plant, which is the coontie plant. The scientific name is Zamia integrifolia. People started planting that in their gardens and lawns because it's attractive. They didn't know it's the host plant of the Florida atala, but it greatly benefited the atala.

Ray: So, this butterfly, which used to be only in Southeastern Florida, Fort Lauderdale, Palm Beach, Miami, now has expanded over to the Tampa area. So, the Tampa area has picked up a couple of species, the western pygmy blue and the Florida atala. So, that is a surprising expansion of its range.

Ray: Now, back to the sad side, let’s talk about that regal fritillary. I didn't mention earlier that this wonderful species, that I did my PhD research on, it has disappeared entirely from 13 states. Disappeared entirely. Now, most of those extirpations occurred over 50 years ago, so, not recent, but still.

Ray: It’s really sobering to realize how this gorgeous species used to be in New York, New Jersey, Ohio, and has disappeared from most of the East.

Matthew: I'm jumping to conclusions here, but I'm imagining that agriculture and pesticides.

Ray: Yes. Loss of open, natural open areas. So, to some degree, woody plant encroachment due to the lack of fire, but probably mainly due to conversion to crops and urban areas. 

Ray: What really hit home to me, was when my former mentor, Professor Lincoln Brower, renowned as a monarch expert, told me about seeing regal fritillaries where he grew up in New Jersey when he was a boy in the 1940’s and it's been a long time since they've been in New Jersey.

Matthew: I mean, we would like to try and leave our listeners with a bit of hope, some ideas about what they can do to help, because I know in our line of work it's so easy to get caught in a kind of a doom cycle.

Matthew: You know. Because, there's always bad news. There's always good news too, but balancing out is not always easy. So yeah, we know that butterflies need plants, you know, the right kind of plants and if you live in the Midwest and had room for say only one host plant and one nectar plant, what do you think they would be? I mean, and similarly, if you're in the Northeast or Central or the Southeast? Do you have simple guidance like that?

Ray: I do, and of course the Xerces Society has long lists of plants for pollinators and plants for monarchs on our website, but if I were to choose just one of each for each area. I think in the Midwest, I'd probably go with a milkweed. Probably common milkweed, butterfly milkweed or swamp milkweed, because all 3 of those in addition to helping monarchs, monarch caterpillars, they're also producing nectar for monarchs, and many other butterflies.

Ray: And then if folks listening are from the Midwest or the Northeast if you don't know about a plant called anise hyssop, you should go to the store and get some anise hyssop. It's in the genus Agastache. I'm forgetting the specific epithet at the moment. But anise hyssop is pretty easy to grow. It smells great and it will be covered with butterflies and bees for months. For a perennial, it blooms for a very long time. So, anise hyssop. Yes, a great nectar plant for the North in general.

Ray: The Northeast, I also pick a milkweed as the host plant. For the nectar plant, I would pick slender mountain mint. Yes, slender mountain mint also occurs in the Midwest. Any mountain mint, in the genus Pycnanthemum, gets covered with bees and butterflies and other pollinators while it blooms.

Ray: In the Southeast. That was a little tougher for me to decide. I think for a host plant I will go with prickly ash. In the genus Zanthoxylum. It is a small tree. And it is the one the host plants for the giant swallowtail, the largest butterfly of North America.

Ray: And in my experience, if you have some prickly ash, or any other plants in that family, better native to the US, you will have giant swallowtail caterpillars and they are really fun caterpillars because they look like giant bird turds.

Ray: They’re huge and they really do look like bird droppings and that almost certainly is a defense, a strategy to help make them look unappealing to predators. As far as the nectar plant in the Southeast snow squarestem. Let's go with snow squarestem, Melanthera nivea. I know I used to see that when I lived in Gainesville, Florida and I was visiting my mother in law there, multiple times in the last year, and wow, plenty of things visiting the Melanthera nivea snow squarestem. Beautiful white flowers, easy to grow.

Ray: Where I live in the South Central US, Kansas, Oklahoma, Texas, and neighboring states. For the host plant, I'll go with passion flower because if you grow passion flower in the genus Pasiflora, you will have caterpillars on it. Including variegated fritillaries and gulf fritillaries.

Ray: And matter of fact, I planted some passion flower at a pollinator garden recently. And while we were planting it like 3 min after we had the plant in the ground, there was a female variegated fritillary on it and I'm not exaggerating. And I was at this garden 2 days ago and the caterpillars had almost eaten it down to the ground. So, that's how good of a host plant Passion flower is.

Ray: As far as the nectar plant, people who know me know I'm obsessed with a plant called golden crownbeard, Verbesina encelioides. Pretty yellow flowers, easy to grow as long as you have well drained soil, and it blooms from April until frost. So, it's feeding butterflies and other pollinators from April until frost. Easy, easy choice for me.

Matthew/Rachel: That's great. Thank you.

Ray: You're welcome.

Rachel: Wow, thank you for all those. Just thinking, you know a lot about a lot, Ray. All of these different plants and such a large region.

Ray: I've lived all over. So, I'm an everywhere man, right?

Rachel: Exactly. Well, we're lucky to have you. I know you're just a wealth of knowledge and information and this has been really wonderful. So, we have a different question to end on because you've already answered our first one that we ask. So, what is the most memorable experience you've had with an invertebrate?

Ray: Oh boy. That's a tough one. I've had a lot of great times with bugs. I remember vividly, being out in the field as a new graduate student at the University of Florida with Lincoln Brower, the world's greatest expert on the monarch. And I took him out to one of my field sites, an area where he had never been.

Ray: And he was so much fun to be with because he would get so excited by just about everything in nature. Where I took him was an area full of biting flies, deer flies, mosquitoes, and had water moccasins and alligators. And oppressive heat and humidity. It was a dangerous place. Place with a lot of hazards.

Ray: And yet walking through this swampy area, in an uninhabited, region of the Gulf Coast of Florida, we came upon a tiny patch of white flowers. Tiny little white flowers. Named, turkey tangle foot, is the name of the plant.

Ray: And in that tiny patch of flowers about the size of a typical children's bedroom, we saw 75 queens, which are beautiful chestnut brown butterflies, and 200 great southern whites, which are large, brilliant white butterflies with blue antennae, turquoise blue antennae, and to see this bubbling mass of chestnut brown and white all together, we were just transfixed by the beauty. And to think of that was just in some swamp, some swamp in Florida that not many people ever visit.

Ray: But if you search, you will find some wonderful things. The heat and humidity, especially the humidity of the Eastern US, is really beneficial to our butterflies. And, and I know Rachel and Matthew are both, Matthew lives in the Portland area, and Rachel grew up in the Portland area. I see more butterflies on my farm in Oklahoma in 1 hour than I'll see in 2 weeks in the Portland, Oregon area.

Ray: So, which is not to put down Portland, Oregon, but it's to let people know that, we have very special—we got a lot of butterflies in the Eastern US still, especially in the South. But also, in in the North as well, but especially if you want to see a lot of butterflies you could still go to places with a lot of butterflies down here in Oklahoma and in Arkansas and the rugged places of Florida and Alabama, or Tennessee. So, I think there should be more tourism to this region for butterflies, to be honest.

Matthew: Just thinking I have to go visit.

Rachel: Same.

Ray: Yeah. Well, come on down, please.

Rachel: Thank you for painting that beautiful picture for us Ray and thank you again for joining us and talking about some butterflies other than monarchs. We love monarchs, but we love other butterflies too. And I think you give us just such a really great idea of the diversity and just curiosity. I'm so curious now that I want to go learn more, which is really wonderful. So, we hope to have you back again. I'm sure we will at some point. But thank you again for joining us. We hope you enjoyed your time.

Ray: I really did.

Matthew: Bug Banter is brought to you by the Xerces Society, a donor supported non-profit that works 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.