It’s been another fantastic season at Butterflies & Blooms, which is open through September 5 at the Chicago Botanic Garden. This is my second year working at Butterflies & Blooms, and I think it’s looking better than ever.
The biggest surprise this year happened this week.
We received some big, hairy atlas moth cocoons, and I was a little concerned about whether they would have time to emerge before we have to shut our doors for the season. When I came into the pupae chamber a few days after they arrived, there was a giant female Attacus atlas staring at me, as if to say, “Ha! I showed you!” I chuckled to myself. Our volunteers had also assumed we might not have any more moths this season, so they were equally surprised. I brought it out of the display, its strong feet clinging to my finger. I reached far up into a serviceberry tree and placed the moth where visitors could get an ideal view. Just a few minutes later, a handful of photographers stopped by, and they happily snapped away.
Volunteer Robyn Lynblad came up with the idea of naming each moth the way meteorologists name tropical storms, so we named this one “Aaliyah.”
To make that week even better, a new African moon moth (Argema mimosae) emerged. We are not sure if it’s male or female, so we decided to name it “Bobby.” Bobby and Aaliyah (the atlas moth) will definitely be hanging around for a couple of weeks, so come over and say hello.
Photo by Tony Hisgett from Birmingham, UK [CC BY 2.0], via Wikimedia Commons
Photo by Tucson Botanical (Own work) [CC BY-SA 3.0], via Wikimedia Commons
Butterflies & Blooms will be moving to its new home at the Regenstein Learning Campus in 2017. I can’t think of a more appropriate place for visitors to come to interact and learn about nature in some of its most beautiful forms. Being able to study and interact with nature has a profound effect on people of all ages, especially children. It awakens the childlike wonder that we all have. It certainly has for me.
See Butterflies & Blooms in its current location from 10 a.m. to 5 p.m. daily through September 5, 2016.
We humans have used technology to become masters of communication. But we are far from the only species with an impressive array of “superhuman” abilities. Butterflies have unique features they use for socializing, mating, warding off predators, and more!
Scarlet Mormon (Papilio rumanzovia) Photo by Bill Bishoff
Consider the butterfly’s ability to see ultraviolet light. UV light is a spectrum of light between 10 and 400 nanometers that humans and most other animals cannot sense. Butterflies have complex mechanisms for both receiving and sending UV light, and they use these amazing gifts in a variety of clever ways.
One well-known phenomenon is the relationship between butterflies and nectar-producing flowers. Thanks to special photoreceptors in their huge compound eyes, butterflies can detect ultraviolet light. Many flowers have evolved to display ultraviolet patterning that helps lead the butterflies directly to their nectaries, resulting in a mutually beneficial exchange—nectar for the butterfly, pollination for the flower. These patterns can resemble airport landing strips or helicopter pads, advertising, “The food is in here!” The butterflies easily hone in on these markings and land on the flower petals.
From there, another unique ability helps to ensure the butterflies find what they’re looking for.
A chemoreceptor is a sensory cell or organ responsive to chemical stimuli.
Butterflies have chemoreceptors on their feet (among other places), so when they land on something, they can instantly “taste” whether it’s a food source or not. This comes in handy for food sources that do not have UV patterning, like rotting meat. (Yes, butterflies derive nutrients from deceased animals.)
Some people will be surprised to learn that in addition to sensing ultraviolet light, butterflies can also emit ultraviolet light waves through their wings. Their wings are coated with minuscule scales that can reflect different color spectrums, depending on their shape and the angle of light that hits them.
As the angle of sunlight shifts, the colors emitted from these scales shift. This is how visitors can watch our butterflies “change color” as they flap their wings and flutter about. The structure of these scales reflects many wavelengths of light that we perceive as brilliant colors, but the scales also reflect UV waves, which other butterflies can pick up on for communication.
Since butterflies have many predators, being able to send and receive discrete messages in the form of UV light ensures they won’t be detected. This is often used as a secretive means of courtship. Think of it as two naval ships using their flashing beacons to silently communicate without being detected by enemies. Alternatively, think of it like online dating.
Male butterflies will pick up on the vivid UV patterning of a female, and begin their courtship rituals. The female will check out the UV patterning of the male to decide if he has the right stuff. If he does not, she will assume a posture that I described in my previous post, that is, lifting her wings and abdomen. What I didn’t know earlier was that by lifting her wings, the female effectively covers up the UV light that attracted the male in the first place, causing him to lose interest and leave. I guess things haven’t changed much in the last six million years!
Vogel’s Organ is thought to be used for hearing birds flap their wings. Photo credit: Ray Cannon. Read more about it in Ray Cannon’s Nature Notes.
Noisy butterflies?
As if ultraviolet-manipulation abilities weren’t enough, did you know that our blue morpho and giant owl butterflies have vestigial ears? Called “Vogel’s Organs,” they use these sense receptors to detect birds. Our cracker butterflies (Hamadryas sp.) can use these organs to sense—and create—ultrasonic sound waves to evade bats. What’s more, we have butterflies that can turn the table on their predators by scaring them off using markings that look identical to snakeheads and giant eyeballs!
Starry cracker (Hamadryas laodamia)
Stay tuned for the next installment of news from Butterflies & Blooms—the evolutionary war of super-senses and abilities among butterflies continues.
I remember one day in the exhibition when the weather was lousy. It had been raining all morning. While the volunteers and I huddled around in our ponchos, the butterflies were fine, hanging out in the trees, awaiting the sun. Around noon, the rain finally stopped and the clouds parted, saturating the exhibition with hot, bright sunshine. The exhibition had become a steamy hothouse. At that moment, almost every one of our 200-plus butterflies started flying. They had been waiting all morning for this.
The air in the exhibition was laced with pheromones from many different butterfly species, driving the males into a frenzy. I looked around and watched as male butterflies slammed into one another as they were in hot pursuit of a lone female. Even when two butterflies paired off, there would be a jilted male who wouldn’t give up trying to separate them by trying to knock the pair apart.
I was stunned at the variety and complexity of the courtship dances and rituals being displayed. A pair of Junonia iphita, or chocolate pansy butterflies, would fly to about 5 feet, at which point they would descend in a perfect interlocking spiral, straight down until they hit the ground. They would repeat this courtship ritual over and over again. Another incredible display was the Graphium agamemnon, or tailed jay butterfly.
Tailed jay (Graphium agamemnon) butterfly by Anne Belmont
One tailed jay would fly in a straight line, while a second one (assumedly the male) would rapidly orbit around the first one, sort of like the moon orbiting the earth as it flies through space. This little trick just blew me away. I then noticed butterflies were mating in mid-air. One butterfly would do the flying, while the other would be hanging precariously below. This stunt was made possible by the male’s “claspers.” These claspers work exactly as they sound: they grab hold of the female, making sure that they remain together.
Great yellow mormon (Papilio lowi) butterfly by Anne Belmont
Leopard lacewing (Cethosia cyane) butterfly by Robin Carlson
There were many more amazing acts of nature going on during this incredible spectacle. Some butterflies would attempt to mate with a different species. Sometimes males would try to mate. I even spied a trio of butterflies interlocked, forming a tangle of wings pointing in every direction. Two were a pair of Papilio lowii, or yellow mormon butterflies, while the interloper was a Cethosia cyane, or leopard lacewing. Now I thought I had seen it all. These butterflies were making human relationships seem tame. Visitors were enjoying the show, too. They would say, “This is supposed to be a ‘family’ exhibit!”
Females who had already mated or just weren’t impressed by the males would sit on a leaf with their wings spread and their abdomens held high in the air. This made mating impossible.
Blue Morpho (Morpho peleides) by Bill Bishoff
Then, I saw something really baffling. To this day, lepidopterists know very little about the courtship of everyone’s favorite butterfly, Morpho peleides, the blue morpho. It started when one blue morpho clung to the netting of our enclosure.
Next, almost a dozen other morphos came over and began to form a very tight swarm around the morpho hanging on the netting. The group formed a writhing cloud around the butterfly on the netting, bumping into each other and circling around the individual. I did not see any of them pair off and mate. They just danced frenetically around the center morpho.
Was the center morpho somehow the only female, and all the males were simply trying to mate with her? I doubt it. We usually have an even ratio of males to females in the exhibition. Perhaps the center morpho acted as a beacon, releasing pheromones so that her kind would gravitate toward her designated “mating area” and mate with one another. She was the orchestrator of the ritual, silently sitting and directing her kin to carry out their biological imperative.
Large tiger longwing (Lycorea cleobaea) butterflies mating in the exhibit; photo by Jill Emas Davis
The moral of the story is this: run to the butterfly exhibition if it has recently stopped raining. You might get a chance to see some amazing butterfly mating behavior.
Butterflies & Blooms is open daily, 10 a.m. to 5 p.m. through September 5, 2016. Bringing the family? Our Summer Family Fun Pack includes parking and five tickets to Butterflies & Blooms and the Model Railroad Garden.
Here at the Chicago Botanic Garden’s Butterflies & Blooms, we have a variety of butterfly species that fall under the genus Heliconius. This fascinating group is commonly referred to as the longwings.
Longwings are native to the tropical and subtropical regions of the New World. This includes South America, Central America, and the southern United States. Florida’s state butterfly, the zebra longwing (Heliconius charithonia), has been found as far north as South Carolina.
Zebra longwing butterfly (Heliconius charithonia)
Despite their diminutive size, zebra longwings are noted for their long lifespans, which can be several months rather than several days or weeks. This is thanks to their ability to use pollen as a food source. Unlike nectar, pollen is rich in protein, and this healthy diet allows them to remain fertile for a longer period of time.
Mimicry in butterflies illustrated on these plates showing four forms of Heliconius numata, two forms of H. melpomene, and the two corresponding mimicking forms of H. erato. Image by see Source [CC BY 2.5], via Wikimedia Commons.
Heliconians are also known to be very “intelligent” and social insects. They roost together in large groups, respect their elders by giving them the best roosting spots, and even wake each other up in the morning by gently nudging one another. At Butterflies & Blooms, you can usually find them comingling in loose groups called “flutters,” roosting in long rows on our serviceberry trees, or even mating.
Like Darwin’s finches of the Galapagos Islands, the Heliconians have provided evolutionary biologists with a wealth of information and are studied more than any other butterfly. In the Amazon, Heliconians hybridize, form subspecies and local phenotypes, and mimic one another, confounding even the most seasoned lepidopterists.
Longwings have a unique and bizarre mating tactic called pupal mating that is not seen in most butterflies. Males will seek out female pupae and insert their abdomens into the chrysalids, fertilizing the females’ eggs before the butterflies finish emerging from the pupal stage. Scientists are currently studying the evolutionary effects that this tactic may have.
At Butterflies & Blooms we always have Heliconians flying around. You may find the postman, zebra longwing, Doris longwing, and many others. Ask us where to find them and we’ll point you in the right direction. Until next time, enjoy the gardens and keep your antennae up for future updates.
Greetings from Butterflies & Blooms! I have great news for my fellow Lepidoptera enthusiasts! We have a very interesting new species in the exhibition. Meet Caligo atreus, also known as the yellow-edged owl, or our favorite: the magnificent owl.
When resting, the eyespots of Caligo atreus are clearly visible. Photo by Stuart Seeger via Wikimedia Commons
This blue beauty is in the genus known as the owl butterflies (Caligo). They’re called owl butterflies because the markings on the undersides of their wings have large black eyespots that resemble the eyes of an owl. (You will typically see the eyespots when the butterflies’ wings are closed.) This is thought to help them ward off predators. Caligo translates to “darkness,” which corresponds to the fact that they prefer to fly in the early morning before their predators are out and about. They are native to the tropical forests of Central and South America, and are among the world’s largest butterflies!
A dorsal view of Caligo atreus, showing off its beautiful markings
We also have a few other species in the owl genus, including the giant owl and the forest owl. However, the magnificent owl is aptly named, as it is much more colorful than its peers—its dorsal side has deep blue striping on the top part of the wing and bright yellow on the bottom half of the wing. During most of the day, you can find them hanging out on the fruit trays or resting in the shade, but if you come early, you’ll have a good chance of catching these graceful giants dancing around the exhibition, showing off their beautiful coloration.
Join us for our final week of Butterflies & Blooms, open through September 7. See you next season!
