HMNS greenhouse teaches how to plant a butterfly oasis in your back yard

They float on the wind, decorate your back yard in the spring and summer, and inspire warm emotions with their delicate wings. They seem carefree, at home in any meadow, but butterflies have more specific needs than we might imagine.

monarch

Monarch butterflies don’t live just anywhere; they need habitat, too!

As urban sprawl continues to grow, reducing green space and native plant growth, natural butterfly habitats are shrinking. Butterflies require specific plants on which to feed and lay eggs. Caterpillars are finicky eaters.

Soni Holladay, Houston Museum of Natural Science Horticulturist and Greenhouse Manager, will lead a class Saturday, April 18, beginning at 9 a.m., to share information with the public about how best to plant a garden that will attract native butterfly species, creating a backyard butterfly nursery.

Holladay’s main concern is planting tropical milkweed to attract the famous migratory monarch butterfly. Though tropical milkweed is easier to grow, scientists have discovered it may play a part in declining monarch populations.

A parasitic species of protozoan called Ophryocystis elektroscirrha, or simply Oe, grows on the body of their monarch hosts. When infected monarchs land on milkweed to lay eggs, Oe spores slough off and are left behind. Caterpillars, which eat the milkweed, ingest the spores and become infected.

When the protozoans become too numerous, they can overwhelm and weaken individual butterflies, causing them to suffer. Several heavily infected monarch can take a toll on the local population. Oe can kill the insects in the larval or pupal stage, as well, before they can reach full adulthood.

Asclepias_curassavica_(Mexican_Butterfly_Weed)_W_IMG_1570

Tropical milkweed survives the Houston winters, making them a perennial plant and a possible danger to monarch butterfly populations.

Native milkweeds die off every year and grow back in the spring Oe-free as part of their cycle, but the evergreen tropical milkweed remains standing year-round, providing a vector for the protozoan to spread.

“We’re advising everyone who plants tropical milkweed to cut it back once a year or more,” Holladay said. Much like their native cousins, the tropical variety will return later, a healthy habitat for butterflies.

Holladay’s class will offer more details about this and other butterfly-raising issues. After the class, guests will tour HMNS greenhouses and our on-site butterfly-rearing operation. Tickets $23, all ages. Native milkweed plants and other seeds will be available to get you started.

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

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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!

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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).