The Butterfly Center beat: Everything you ever wanted to know about raising Atlas moths

Image

The Atlas moth (Attacus atlas) is a large moth belonging to the Saturniidae family. Saturniids, familiarly called giant silk moths, include some of the largest species of Lepidoptera (moths and butterflies). Two local species that may be familiar to readers are the polyphemus and luna moths.

Atlas moths are considered the largest moths in the world in terms of total wing surface area. Their wingspans are also among the largest, often reaching over 10 inches. They are strikingly beautiful, with tawny wings punctuated with translucent “windows” bordered by black. Their most distinguishing feature (other than their size) is an extension of their forewings that resembles a snake’s head, thought to be a means of scaring off potential predators.

The forewing of an Atlas moth resembles a snake’s head. ©Erikki Makkonen

The forewing of an Atlas moth resembles a snake’s head. ©Erikki Makkonen

These spectacular moths make superb additions to the Cockrell Butterfly Center. During the day, they spend most of their time motionless, clinging to the side of a tree or other surface. Visitors can thus get up close to intimately study these creatures, and can clearly observe their fat, furry bodies, fuzzy antennae, and teddy bear like expressions.

Close-up of the fuzzy face and feathery antennae of a female Atlas moth (males have larger antennae). © John Horstman

Close-up of the fuzzy face and feathery antennae of a female Atlas moth (males have larger antennae). © John Horstman

Once night falls, the male Atlas moths take flight in search of a female. The search has a sense of urgency, as adult Atlas moths typically live only about one week. This is because the adults do not have fully formed mouth parts and therefore cannot eat; they are sustained only by the fat reserves they built up as a caterpillar. The moths will quickly mate, lay eggs, and die soon after.

One day at the Cockrell Butterfly Center, a male and female emerged from their cocoons around the same time. We took the opportunity to breed and raise this species of moth. The newly emerged male and female were placed in a flight cage in the greenhouses on the top level of the museum parking garage. They paired the very first night they were together. During mating, the moths remained coupled for several hours. Then, over the next three days, the female laid approximately 150 crimson eggs, placing them indiscriminately along the walls and edges of the flight cage.

A mating pair of Atlas moths clinging to the sides of a flight cage. The larger of the two is the female.

A mating pair of Atlas moths clinging to the side of a flight cage. The larger of the two is the female.

Atlas moth larvae are generalists, meaning they will feed on a wide variety of host plants (but not all plants). Hoping to determine which of several possibilities would be the best food for our caterpillars, we searched the literature for recorded host plants.

We chose four that we had available, including Camphor Tree (Cinnamomum camphora), Vitex (Vitex trifolia purpurea), Mahogany Tree (Swietenia mahoganii) and Sweet Potato Vine (Ipomoea batatas). Gathering the eggs, we divided them among four plastic containers lined with moist paper towels and ventilated with tiny holes poked in the lid, each containing a different kind of leaves.

The eggs took 10 days to hatch. The hatchling larvae were covered in pale protuberances and had black heads. After eating their eggshell, the tiny caterpillars began eating the provided foliage. Once the caterpillars were feeding reliably, they were moved to netted cages containing potted plants, so the leaves would be constantly fresh.

The caterpillars hatched on a Friday in September. To track their weekly growth and development, we took a photograph of them each Friday thereafter. It quickly became obvious that the caterpillars on Camphor were thriving: they grew bigger and faster than their siblings on the other plants (the pictures shown below are of larvae fed on Camphor). In each photograph, larvae were placed next to a standard sized Popsicle stick, fondly known as “Size Reference Ralph,” to track their relative growth.

The caterpillars took six weeks from hatching to pupation. They ate voraciously, becoming soft and fleshy to the touch, and were a pale blue-green color. Their backs were covered in a Mohawk of tubercles with a thick, waxy, flaky coating. After six weeks, the caterpillars were almost as long as Size Reference Ralph and were quite pudgy.

The sequential pictures show the dramatic changes in the larvae, followed by the start of silk spinning, and finally a complete cocoon. Once they finished their cocoons, the larvae pupated inside. We then gently moved the dried cocoons to the emergence chamber inside the entomology hall of the Butterfly Center.

Egg to cocoon in Atlas Moths. Pictures were taken one week apart next to Size Reference Ralph. ( Pictures courtesy of Lauren Williamson)

Egg to cocoon in Atlas Moths. Pictures were taken one week apart next to Size Reference Ralph. (Pictures courtesy of Lauren Williamson)

Then we waited. Atlas moths may eclose from their cocoon in as little as three weeks, but can sometimes take several months. To escape from their silken enclosures, they must excrete a substance that dissolves a hole in the silk, allowing them to crawl out. They then cling to their cocoons while their wings expand and dry.

The first Atlas moth of our batch of cocoons emerged on Dec. 17, almost 3 months after hatching from the egg. It was a large female, with a wingspan of just over 10 inches. As you can see, Size Reference Ralph was dwarfed by her!

Our first Atlas Moth to emerge on Dec. 17th 2013. (picture courtesy of Lauren Williamson)

Our first Atlas moth to emerge on Dec. 17, 2013 (picture courtesy of Lauren Williamson).

Know a girl who’s interested in math and science? Come to GEMS (Girls Exploring Math & Science) on Sat., Feb. 8 from 9 a.m. to 1 p.m. The Museum will be filled with hands-on science and math for everyone to experience. Local professionals will be at the Museum to answer questions about their careers in the fields of science, technology, engineering and math.

The event is free with paid admission to the Museum. Click here for $7 admission to all permanent exhibit halls on Sat., Feb. 8.

 

 

Spring Plant Sale!! This Saturday, 4/9

The Cockrell Butterfly Center is having its Spring Plant Sale Saturday, April 9, 2011, from 9 a.m. to 1 p.m. on the 7th level of the parking garage at the Houston Museum of Natural Science.

Make sure to get there early as plants do sell out! This post is by Soni, one of our Butterfly Center horticulturalists.

HMNS Fall Plant Sale
See more photos from the Spring Plant Sale on Flickr.

We have nectar plants and host plants to attract butterflies to your garden. This year, we have been working on propagating more native plants. This includes:

Black-eyed Susan (Rudbeckia hirta)
Giant Coneflower (Rudbeckia maxima)
Mexican Blanket (Gaillardia pulchella)
American Basket Flower (Centaurea Americana
Creeping Spot Flower (Acmella oppositifolia)
Maypop Passion Vine (Passiflora incarnata)
And others!

Tithonia
See more photos from the Spring Plant Sale on Flickr.

Some of you are probably seasoned butterfly gardeners, but some may be asking yourselves:

How do you garden for butterflies?

The answer is really simple. There are two types of plants that you need to have for a successful butterfly garden: nectar and host plants. Nectar plants have blooms that produce a sugary liquid that butterflies need to consume in order to survive. Some examples of these plants are Porter Weed, Echinacea (Purple Cone Flower), Zinnias, Rudbeckia (Brown and Black-eyed Susans), Monarda (Bee Balm), Lantana, Salvias, Eupatorium (Mistflower), Cuphea, Buddleia, and Tithonia (Mexican Sunflower) among many others.

Gaillardia
See more photos from the Spring Plant Sale on Flickr.

The other type of plants that you need are host plants. Some examples of these are: Asclepias (Milkweed), Passionvine, Citrus, Rue, Fennel, Aristolochia (Pipevine), and Cassias. These are plants that the female butterflies lay eggs on. Certain species of butterflies will only lay their eggs on specific plants such as the Monarch, which only lays eggs on Milkweed. If you see caterpillars on these plants, that is a good thing! Those caterpillars are baby butterflies! The host plant is their food source, which means that the caterpillar eats the leaves. If you want a garden to attract butterflies, but don’t want insects eating away at the foliage, just use nectar plants.

Create a Local Butterfly Habitat!

A lot of these plants are native to Texas and the good thing about this sale is that the Cockrell Butterfly Center specifically chooses plants that will attract the native butterflies and will perform well in the Houston area. If you are not sure what to do or have any questions about gardening for butterflies, our experts will be at the sale to answer them. Come early, the plants go fast!

Cure Nature Deficit Disorder – Take Your Kids Outside!

>
Building a compost heap

Every week I volunteer at a local elementary school in the arboretum and gardens on the schoolgrounds. The PTA environmental chair and I recently turned an area into a vegetable garden and built a large compost bin. We’ve told the teachers about what we’re doing, and some of them have brought their classes out to help us plant.

The kids are enthusiastic diggers and rakers; we’ve had to buy more kid-sized spades and rakes to prevent struggles to “have my turn.” They love to find june bug grubs (bad for baby plants) and earthworms (good for the soil).

They are eager to start the compost pile and feel how warm it gets as it decomposes. Most of them have never planted seeds before, and are amazed to learn what a baby radish or a seedling broccoli plant looks like. This week the sugar snap peas are getting ripe, and I worry that there will not be enough pods to go around to the class that planted them – and I know everyone is going to want to eat one!

Laying out the compost bins

Helping the kids to plant a garden takes me back many years. I fondly remember helping my parents to tend our vegetable garden in Calgary’s short growing season (no tomatoes there!). My father and I would often go out with a flashlight after dark to pick the slugs off the beans and lettuce, dropping them into a can of salty water. The few ears of corn we got each year would be relished as a special treat, cooked and eaten only minutes after they were picked. Besides harvesting our garden crops, we would also go out looking for wild june berries (called Saskatoons in Canada), tiny wild strawberries (so flavorful), or crabapples and chokecherries that my mother rendered into jelly or syrup.

I was very lucky to grow up when and where I did. But surely all kids should have a chance to learn how plants grow and what bugs live in their backyard or the overgrown area behind their fence. Things are different today – kids are busier, more sheltered, and many of their parents are uncomfortable in the outdoors. These days many people turn their gardening over to a landscaping crew, and their kids never work out in the yard (in contrast, us kids had to mow and edge our huge lawn all summer, and rake up all the leaves in the fall – for no pay!).

Today people grow up so distant from nature that it no longer surprises me to meet a grown woman (like the garden club member who visited recently) who hadn’t the faintest idea that butterflies come from caterpillars.

Some of you may have heard about Last Child in the Woods, a book by Richard Loew that has gotten a lot of attention over the last few years. Loew coined the term “Nature deficit disorder” and convincingly argues that many people today suffer from it, to the detriment of themselves and the world.

I recommend the book, and most of all, I recommend sending your kids to play and work outdoors (if possible, on their own – or if not, with you to guide them).

A day in the life of “Bugs on Wheels”

Bugs on Wheels” is the ever-so-popular outreach program that sweeps Erin and me away from the office on many days.  Our very first program was on Feb. 13, 2006 and needless to say, it was a HIT!  If you have ever wondered what goes on at a “Bugs on Wheels,” wonder no more because you are about to go on a trip with us right now. 

On a typical morning, Erin and I get to the office around 7:00 or 7:30.  We have to take care of our other jobs before we can hit the road.  Erin sorts through the insect zoo while I release butterflies. 

Next, we have to get all the critters ready to go.  All of the bugs that we take with us live in the containment room, so we do not have to take any away from the beautiful displays in the entomology hall.  Everyone gets loaded up in their critter carriers and we stack them all in a large Rubbermaid container with wheels. 

Then we are out to my car and on the road.  We have traveled as far away as Crosby and as close as just around the corner.  Set up is really easy, so we typically get to a school 10-15 minutes early.  Normally, we have to sign in at the front office where we almost always get bombarded with students and teachers asking “What is that??”  We prefer to set up in a classroom away from others, but there have been times when we had to fight the noisy crowds in a library or a cafeteria. 

Typically we do 30 minute presentations, especially if the students are younger than 3rd grade.  The older kids tend to sit still longer, allowing us to gab away for 45 minutes to an hour.  Once the kids enter the class, the first challenge is to sit them all in nice straight rows.  This part is hard for kids of all ages because they are distracted by the bugs of course! 

Erin and I take turns introducing ourselves to each class.  We tell them that we are from the Houston Museum of Natural Science and that we work in the Cockrell Butterfly Center.  We used to ask if anyone has been to HMNS, but we stopped doing that because every kid wants to tell a story of their visit here. 

We always like to ask the kids questions about insects before we begin; stuff like: How many legs? (6) How many body parts? (3: head, thorax, abdomen) What do they use to smell? (antennae) What kind of skeleton do they have? (exoskeleton)  Do they have wings? (some do) 

After this introduction, Erin and I turn almost invisible because the bugs totally steal the show! 

First, we talk about all of the insects: hissing cockroaches, 3 walking sticks, deer – horned stag beetle, and the giant long – legged katydid.  I have to say the most impressive is the katydid which the kids really love.  We bring up important facts about each bug and ask lots of questions to the audience.  Things like camouflage, mimicry, environment, adaptations, and diet are among some of the things we like to talk about. 

Next, we discuss arachnids and compare and contrast them with insects.  The two arachnids we show the kids are the whiptail scorpion, aka vinegaroon, and Rosie, our rose-hair tarantula.  This section gives us the opportunity to clear up some misconceptions about tarantulas.  Most people think they are soooooo venomous and cannot believe we actually hold one. 

Lastly, we pull out the giant African millipede and have them guess what it is.  Every now and then we will get a correct guess, but the majority of the guesses are: caterpillar, snake, worm, snail, rollie pollie, and centipede.  We actually have a preserved centipede that we can compare the millipede to and show the differences. 

The best part about our presentation is that every kid, if they want to, can touch all of the bugs with the exception of the vinegaroon and the stag beetle, who don’t like to be touched.

Once we are all finished, we open the floor up to questions and eventually move on to the next group!  Some days we do six, 30-minute presentations and others we do three, 1-hour presentations.

lost its leg but determinant ...
Creative Commons License photo credit: challiyan

For us, this program is very rewarding.  One of the best things is when a kid says “YUCK” when they first see the bug, but after we persuade them to touch it they think it’s cute.  Also, helping kids understand that bugs aren’t so bad and many of the big and scary ones are just trying to protect themselves from predators and that they don’t really want to hurt us. 

The most priceless moment is the initial excitement they get when they first see each bug – and the escalated joy when they find out they can actually touch the bug!

For all you parents and teachers out there, I have great news!  Our Bugs on Wheels program has expanded to three different and unique programs. 

The program I just explained is now considered “Amazing Arthropods.”  One of our new programs, “Butterflies and Moths,” introduces the amazing cycle of metamorphosis and shows how butterflies and moths differ from each other and from other insects.  The other program, “Plants and Pollination,” uses a giant flower model, puppets, a bee hive, and real fruits and vegetables to demonstrate the importance of pollination to the plant kingdom and especially to the foods we eat. 

If you are interested in our programs, please feel free to leave a comment here, or contact us at bow@hmns.org.