Archives For Patrick Sbordone

At the Chicago Botanic Garden’s Butterflies & Blooms exhibition, I receive a wide variety of questions about butterfly physiology. My favorite questions are ones that don’t have a substantiated answer, only theories posited by lepidopterists (or those who study butterflies and moths). I always enjoy these questions, since they are on the cutting edge of scientific understanding.

One such question is: “What are those specs of gold on the monarch butterflies?” The short answer is “Nobody knows!” But there are a few interesting theories.

Zebra longwing chrysalis (Heliconius charithonia) top view, showing gold markings

Zebra longwing chrysalis (Heliconius charithonia) top view, showing gold markings; photo via BugGuide.net. Copyright © 2006 Hannah Nendick-Mason

Lepidopterists approach strange features such as metallic markings by asking, “What sort of advantage would this feature give to the butterfly?” Every trait found in nature exists because it gave that individual more opportunities to reproduce. Perhaps the trait helps keep the butterfly from being eaten, or it gives a male butterfly bright colors to impress the ladies, or perhaps it allows the butterfly to utilize new food sources when nectar isn’t available.

When butterflies emerge from their chrysalids, they are very vulnerable to predators like birds, since they can’t move. Their only defense is to display colors and patterns that either signal poison or blend into the environment. That means the features we see on chrysalids are no accident, as they offered an advantage and were subsequently passed down.

Camouflage is the prevailing theory as to why chrysalids sometimes have metallic spots, but wouldn’t a bright spec stick out like a sore thumb? One theory is that the specs imitate the iridescent glistening drops of dew on a leaf in the morning or after a rain.

Another theory is that the gold specs are a way of the pupae shouting, “I’m poisonous! Leave me alone or you’ll be sorry!” In the world of insects, reds, oranges, and yellows universally indicate poison, whether the insect is actually poisonous or not. Many insects, including butterflies and their pupae, use this trick to their advantage. My favorite trick is when a chrysalis has evolved to look just like a little snake. Imagine how shocked a bird or a bat would be when it discovers it’s next meal might actually make a meal out of it instead!

spicebush swallowtail caterpillar

Butterflies have adapted a variety of techniques to ward of predators while pupating, such as mimicking snakes or simply blending in. Photo by Judy Gallagher via Wikimedia Commons

Water drops in nature

One theory for the gold and silver spots found on chrysalids is to mimic water droplets.

While monarchs and longwing butterflies have gold specs, we often have species of butterflies that decided to have even more swagger by making their chrysalids appear to be solid gold. Guests often compare them to exotic gold jewelry. These pupae are so shiny, you can clearly see your own reflection in them—and that’s the point. What better way to blend into your habitat than to literally mirror it? This is the prevailing scientific theory, anyway.

Solid gold pupa

Pupae that are fully metallic are thought to blend in by literally mirroring their surroundings. You can actually see my phone and hands reflected in the chrysalids.

When you see a metallic spot on a butterfly chrysalis, you are seeing yellow and orange pigments, but it’s the intricate microscopic structure of the outer chrysalis that gives it its metallic sheen. This is where things get a bit more complicated. Entomologists refer to the outer surface of metallic chrysalids as “multiple endocuticular thin alternating layers.” That’s quite a mouthful, so they call it M.E.T.A.L. for short. The acronym fits perfectly.

Here’s another way to think of what you are seeing: Imagine a butterfly’s chrysalis as several thinly stacked layers of windows. When sunlight hits these windows, they absorb and reflect light, giving a glimmering effect.

In each phase of a butterfly’s life cycle, it is extremely vulnerable to being eaten. From slow, plump caterpillars to immobilized chrysalids to paper-thin, delicate adults, they’ve found ingenious ways to survive and reproduce. Come to Butterflies & Blooms and see for yourself.


©2018 Chicago Botanic Garden and my.chicagobotanic.org

Don’t trust your eyes—that leaf is actually a butterfly

The orange dead leaf (Kallima inachus)

Patrick Sbordone —  July 20, 2017 — 2 Comments

As the season has been progressing at Butterflies & Blooms at the Chicago Botanic Garden, we have been lucky enough to receive a very special butterfly species and a definite crowd-pleaser: the orange dead leaf (Kallima inachus)

If we didn’t point out this character to guests, no one would ever suspect that they were looking at a butterfly.

I like to describe the orange dead leaf butterfly as being able to mimic a dead leaf better than an actual dead leaf can. When it closes its wings, the butterfly has a perfectly ovate silhouette, complete with both a pointed leaf apex at the front tip and a petiole, or the stalk that attaches leaf to stem, on the hindside. The wing is a drab brown, with leaf vein arrangement very similar to that of a flowering dogwood. The orange dead leaf butterfly is at home in broadleaf forests of India, where it blends in with dead foliage during the dry season, going unnoticed by all but the sharpest predators. Here at Butterflies & Blooms, this butterfly seems to seek out dead, brown leaves in the tree canopies and uses them as a place to blend in. I always get a kick out of showing people that one of those dead leaves is not what it seems.

Kallima inachus at rest on a branch

Kallima inachus at rest on a branch

Kallima inachus with its wings open

Kallima inachus with its wings open

The butterfly has another surprise for visitors: It has incredibly vivid coloration on the dorsal side of its wings. When the orange dead leaf opens its wings to sun itself or take flight, it shows off its navy blue iridescent wings, with a bright orange stripe on each of the forewings.

We have several other butterfly species that also use one side of their wings to resemble dead foliage, including the autumn leaf (Doleschallia bisaltide) and the great orange tip (Hebomoia glaucippe). However, these species have not mastered the art of camouflage quite like Kallima inachus. Come over to Butterflies & Blooms to check out this fascinating butterfly.


Atlas moth (Attacus atlas)

Atlas moth (Attacus atlas)

While you are here, take a look at the serviceberry tree just to the left of the pupae chamber. We have an unprecedented seven giant atlas moths perched on the tree branches like Christmas tree ornaments. Also, don’t miss all of the blooms: The recent rainy weather has undoubtedly helped the Butterflies & Blooms garden become more floriferous.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Butterflies & Blooms has moved to the Regenstein Learning Campus and I have good feeling it’s going to be the best season yet, because we currently have a plethora of butterfly species native to Brazil. The Chicago Botanic Garden is celebrating Brazil in the Garden this summer, and Butterflies & Blooms is part of the celebration. 

Since we first opened Butterflies & Bloomswe have sought to display the most beautiful butterflies in the world, both exotic and domestic. Naturally, the Amazon rainforest is one of the most biodiverse regions on the planet. A whopping 60 percent of this precious treasure lies within Brazil. Brazil is home to thousands of butterfly and moth species (in comparison, all of Europe has about 300 species), and scientists have only recorded a fraction of the Lepidoptera species of Brazil and the greater Amazon rainforest.

You can find dozens of butterflies native to Brazil and neighboring countries in the exhibit on any given day. Currently, we have beauties such as the giant owl butterfly (Caligo memnon) and its close relative, the forest mort bleu (Caligo eurilochus). These two butterflies are often confused with moths because of their earth-toned camouflage and also because they are usually found resting on a shady tree branch during the heat of the day.

Large tiger butterfly (Lycorea cleobaea)

The large tiger butterfly (Lycorea cleobaea) thrives in the tropical rainforests of Brazil; find it here in Butterflies & Blooms. Photo ©Anne Belmont.

Blue morpho (Morpho peleides)

One of our most popular butterflies, the blue morpho (Morpho peleides) is another Brazilian native. Photo ©Anne Belmont.

Another pair of Brazilian butterflies that grace the exhibit are the grey cracker (Hamadryas feronia) and the starry cracker (Hamadryas laodamia), They are aptly named, since they can clap their wings while flying in order to make a percussive cracking sound as a means of communication. They use this talent when predators approach, to declare territory, and, of course, for mating. While the grey cracker blends into its environment with its intricate, drab coloration, the starry cracker is very showy, coated with brilliant blue specks on a dark blue field. Looking at it can feel like looking up into a starry night.

At Butterflies & Blooms, you can always find at least a few different species of longwing butterflies (Heliconius). Longwing butterflies have been extensively studied since Victorian times, because they display numerous forms of mimicry. In the late nineteenth century, the naturalist Henry Walter Bates traveled to Brazil and studied these butterflies. He noticed that Heliconius erato would mimic the coloration of other Heliconians, because they were poisonous. This particular form of mimicry was coined  “Batesian mimicry” after the naturalist. When Bates returned from Brazil, he used his findings to help support Charles Darwin’s theory of evolution.

Postman butterfly (Heliconius erato)

One of the longwing butterflies common to Brazil is the postman butterfly (Heliconius erato). Photo ©Anne Belmont

Another naturalist by the name of Fritz Müller observed what became known as “Müllerian mimicry”—also while studying longwings in Brazil. In this case, he noted that multiple species of poisonous butterflies will adopt the same coloration, making it easier for them to be recognized as poisonous would-be predators. Müller’s studies also led him to support Darwin’s theory of evolution.

The Amazon rainforest continues to be a scientific cornucopia to this day. The next time you visit Butterflies & Blooms, check out the owls, crackers, and longwings, and remember that they all represent the natural wonders of the Amazon rainforest and Brazil. Then take a walk through the Garden to discover more of the vibrant plants and colors of Brazil.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

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.

PHOTO: Photographers snap pictures of our new atlas moth, “Aaliyah.”

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: Atlas moth.

Photo by Tony Hisgett from Birmingham, UK [CC BY 2.0], via Wikimedia Commons

PHOTO: African moon moth.

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.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

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!

PHOTO: Scarlet Mormon (Papilio rumanzovia). Photo by Bill Bishoff.

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.)

PHOTO: Butterfly wing scales under a microscope. Photo credit: Thomas Eisner.

Butterfly wing scales as seen under a microscope. Photo credit: Thomas Eisner. Learn more about butterfly scales from his post, Scales: On the Wings of Butterflies and Moths.

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!

PHOTO: Vogel’s Organ is thought to be used for hearing birds flap their wings. Photo credit: Ray Cannon.

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!

PHOTO: Starry Cracker (Hamadryas laodamia).

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.


©2016 Chicago Botanic Garden and my.chicagobotanic.org