Seeing Stripes: The Zebra Longwing Butterfly

The zebra longwing (Heliconius charithonia) is a common resident of the Cockrell Butterfly Center (CBC). This butterfly is easily recognizable with boldly striped yellow and black wings. When visiting the CBC, you’ll often spot them sipping nectar from the flowers and nectar feeders or sunning themselves with their wings spread open. These butterflies have some unique features and behaviors that set them apart form the rest!

Aposematic Coloration

Bright, contrasting warning colors are known as aposematic coloration. They indicate to potential predators of the “unprofitability” of a prey item. The bold yellow and black stripes on the zebra longwing serve as a warning signal to potential predators of the butterfly’s unpalatable and poisonous nature. Zebra longwing caterpillars feed on passion vine (passiflora) leaves and acquire some of their toxins, making them distasteful to predators. 

zebra

Bright, contrasting colors warn predators to stay away.

Pollen feeders

Most butterflies can only sip fluids with their proboscis, most commonly flower nectar. Zebra longwings, on the other hand, also feed on pollen. They use their saliva to dissolve the pollen and take in its nutrients. Pollen, unlike nectar, contains proteins and is very nutritious. Pollen feeding is correlated with overall higher fitness. This diet allows zebra longwings to live longer (up to six months) and increases females’ egg production. 

zebra pollen face

You can see pollen on this zebra longwing’s proboscis. Feeding on pollen increases longevity.

Pupal Mating

Male zebra longwings exhibit pupal mating, zebra_longwing_and_chrysaliin which they will mate with a female before and immediately after she emerges from her chrysalis. Males will seek out a female pupae and will perch on it and guard it from competing males. Many males may fight for the opportunity to mate with the yet-to-emerge female. The successful male will insert his abdomen into the softening pupae and copulate with the female. Mating will continue as she emerges and dries her wings. The males will pass a nutrient-rich spermatophore to the female which reduces her attractiveness to future mates. This male (at right) begins mating with the female before she has even emerged from her chrysalis.

zebra_longwings_mating_elizabeth

This mating pair shows the freshly emerged female still clinging to her chrysalis.

Communal Roosting

Adult zebra longwings roost communally in groups of up to 60 individuals at night. They tend to return to the same roost on a nightly basis. In the late afternoon, zebras can be observed fluttering and basking near their roost site as they slowly gather together for the night. Roosting together provides protection from predators and retains warmth. 

zebra-longwing-roosting-fmel-9

These zebra longwings are preparing for the night by roosting together for safety.

So now you know! These beautiful, brightly colored butterflies are bad-tasting, and long-lived. They have unique mating habits and the snuggle together at night. Something to remember next time you visit the zebras at the CBC!

Top 5 Most Frequently Asked Questions in the Cockrell Butterfly Center

The Cockrell Butterfly Center (CBC) strives to bring the natural world to within the public’s reach. Visitors enjoy tropical plants and exotic animals exhibited throughout the indoor rainforest, insect zoo, and practical entomology hall, and as they wander through the CBC, they’re sure to ask tons of questions! To keep you informed, we’ve compiled a list of the top five most frequently asked questions about the CBC and answered them below. Take a look!

Q. Is that real?

A: It depends on what you are asking about.

Usually this question is asked about the chrysalids hanging in the emergence chamber. In that case, the answer is yes! All the chrysalids you see are real! We receive between 800 and 1,000 chrysalids per week. The chrysalids are carefully glued up so the butterflies can emerge in a natural position. If you look carefully, you may see the chrysalids wiggling. You can also observe the freshly emerged butterflies drying their wings. Twice a day, we collect the butterflies with fully dry wings and release them into the CBC rainforest. On Wednesdays until Labor Day weekend, you can watch how we do it during our Wing It! presentation.

chrysalis board

These chrysalids are real! Soon butterflies will emerge from each one.

When this question is about the plants in the Rainforest Conservatory, the answer is also yes, but with one exception. All the plants are real except for the huge central tree. This tree contains the rainforest’s air circulation system. All others are living plants that are meticulously cared for by our staff horticulturalist, Soni Holladay. Each plant is labeled, so keep a lookout for a coffee tree, chocolate tree, pride of Trinadad, pineapple plants, miracle berry bush, and a variety of beautiful orchids. 

Before and after! All the plants in the CBC are real with the exception of the large central tree.

Before and after the completion of CBC construction. All the plants in the CBC are real with the exception of the large central tree.

Q. How many butterflies are there in here?

A. We keep a collection of more than 1,500 live butterflies in the CBC rainforest at all times. It may seem like more or less, depending on how active the butterflies are. The butterflies are most likely to be actively flying and feeding when there is bright sunlight and warm weather. During these times, the whole rainforest feels like it’s fluttering around you. Early in the morning, or in cooler, overcast weather, many of the butterflies will be quietly roosting underneath leaves. During these times, a sharp eye will allow you to spot the sleeping butterflies all around  you. Take this time to enjoy the variety of colors and patterns that are more easily discernible on butterfly wings that aren’t flying. Owl butterflies, however, are active at dusk. You can watch hundreds of them swirling in our rainforest during our limited-availability event An Evening With Owls, coming in September.

roosting

Shhhhhhhhhh! They’re sleeping! Look for roosting butterflies hanging from leaves next time you visit the CBC.

Q. Where do the butterflies come from?

A. We receive the butterflies in their pupal form (chrysalis) through the mail. Each week, we import up to 1,000 live chrysalids from butterfly farms in Central and South America, Southeast Asia, and Africa. We also raise a small portion of the butterflies in the greenhouses on the top level of the parking garage. We receive up to 150 different species of butterflies throughout the year. Use the butterfly identification guides as you enter the rainforest to help you identify some of our most common species!

shipment

Our butterflies are shipped from farms all over the world!

Q. What do the butterflies eat?

A. The CBC rainforest is always full of a variety of flowering plants. Most butterflies feed on nectar. Watch the butterflies visiting the blooms and you will notice them extending their proboscis into the center of the flower. They use this mouth part like a straw to draw up the nectar. Supplementary food is provided for the nectar-feeders in feeding stations filled with artificial nectar. Artificial nectar is made from a mixture of water, sugar and amino acids. It is soaked into sponges that the butterflies can visit to get an extra snack. But not all butterflies feed on nectar. Some prefer the juices from rotten fruit or tree sap. For the fruit-feeders we provide banana brew (fermenting bananas, sugar and beer mixture) as well as slices of over-ripe fruit. Butterflies are also known to feed on some less savory substances such and dead animals and feces.

GF on Eupatorium 2

A butterfly uses its proboscis to sip nectar from a flower.

butterflies eat gross things

Fun fact: butterflies also get essential nutrients by feeding on feces and carrion!

Q. How long do the butterflies live?

A. It depends. Most butterflies are not long-lived. The average life span for the butterflies in the CBC rainforest is about two weeks. Some, like the Atlas moth, only live a few days. Atlas moths don’t even have mouth parts as adults, so they don’t feed at all! They live off of the fat stores they accumulated as a caterpillar. Several of the long-wing species of butterflies may live up to a couple of months. Perhaps the most well-known species of butterfly, the Monarch, is known for  its amazing migration from Canada to Mexico. The migratory generation of Monarchs can live between 6 and 9 months!

monarch and chrysalis

The Monarch butterfly has a long-lived generation that allows it to migrate from Canada to Mexico.

We hope you enjoyed our quick Q&A session! Drop by the CBC any time to satisfy your curiosity further. We’re always around to answer questions.

Buzz or flutter: Who matters when it comes to pollination? (Hint: It’s everybody.)

In economic terms, bees far outstrip butterflies and moths as pollinators. However, there are some plants that are exclusively pollinated by butterflies — especially some wildflowers and garden ornamentals — and several night-blooming species are specifically pollinated by hawkmoths.

Butterflies and moths are members of the insect order “Lepidoptera” — the scaly-winged insects. In addition to the scales covering adults’ wings, Lepidoptera have unique mouth parts as adults: a long, thin, double-barreled, flexible “straw” that is kept coiled up when not in use and extends to reach deep into flowers to extract nectar. This long proboscis means the plants that butterflies and moths typically pollinate have long, thin floral tubes, making the nectar inaccessible to other pollinators with shorter tongues, such as bees or flies.

courtesy of Wikimedia commons

The technical term for butterfly pollination is “psychophily” — psyche being Greek for butterfly.  Butterfly-pollinated flowers are usually brightly colored (butterflies have the widest-known range of color vision in the animal kingdom), especially in yellows, oranges, reds, pinks, and purples or combinations. Scent is apparently not important for butterflies.  However, the flower structure and position is important.  Butterfly-attracting flowers are often produced in showy terminal clusters of smallish blossoms, each with a floral tube that contains nectar and is easily accessible by the butterfly’s long proboscis.

Smaller flowers are usually pollinated by smaller butterflies, which have relatively shorter probosces; large butterflies such as swallowtails have very long probosces and a longer “reach.” Some familiar examples of “classic” butterfly-pollinated flowers are pentas, lantana (indeed many plants in the verbena family), thistles and coneflowers (and many other members of the sunflower or aster family), and milkweeds, among others.  Milkweeds are especially interesting as their pollen is not powdery but occurs in masses or pollinia, each of which bears a little hook that catches on a butterfly’s leg as it probes among the flower clusters.

A few butterflies (mostly the genus Heliconius in the longwing butterfly family) are known to collect pollen on their proboscis and absorb the amino acids from it.  In general, butterflies do not have the “carrying capacity” for pollen as bees do with their hairy bodies.  However, as they move from flower to flower, enough pollen accumulates on their legs or proboscis to get the job done!

Moth pollination is termed “phalaenophily” (phalaen- meaning moth). A number of moths, including tiger moths, noctuid or owlet moths, and more, visit flowers.  But the best-known pollinators among the moths are the hawkmoths, also known as sphinx moths — the adult form of hornworm caterpillars. These large, powerful fliers are basically the nocturnal equivalent of hummingbirds.  Hawkmoth-pollinated flowers are usually white or pale-colored, making them stand out from the surrounding vegetation at night.  They have long floral tubes to accommodate the very long proboscis of these moths, and many are highly fragrant in the evening, or may only open after dark.  Some examples are moonflower, Brunfelsia, Brugmansia and Datura, night-blooming jasmine, four o’clocks, and evening primrose.

Back to bees:  most of us think “honey bee” when we think of bees, but there are many other bee species, from the familiar bumblebee (not common in our area) to the giant carpenter bees, to tiny sweat bees and colorful leaf cutter bees. These different bee species also have favorite flowers to visit for nectar or pollen (most bees only collect pollen).  For the technophiles, pollination by bees is called “melittophily.”

The wonderful variety of flowers — their shapes, sizes, colors, scents and time of day they bloom, even their placement on a plant — have all evolved to attract a pollinator, often a specific one.  Since plants are rooted in the ground, they depend on things that move, mostly flying things — whether butterfly, moth, bee, fly, hummingbird, bat, or even wind — to transfer their male gametes (in pollen) from flower to flower so that the plants can make more of themselves through forming fruits and seeds.

Next time you are out in your garden, in a field of wildflowers, in a gardening shop, or any place with an abundance of flowers, stop to look more closely at the blooms and think about what pollinator that plant might depend on for its survival.

Plant Sale: This Saturday

Today’s post was written by Soni, horticulturalist for our Butterfly Center. She and the other employees are hard at word preparing for our upcoming Plant Sale on October 2.

I’m sure not very many of you are thinking of rolling up your sleeves and heading into the blazing heat of summer to do a little gardening. What you should do is start thinking ahead to fall, planning your garden for when the weather cools off and you can once again step outside of the air conditioning without having a heat stroke. If your garden needs a perk up after this summer, you should head over to the Cockrell Butterfly Center’s Fall Plant Sale which will be this Saturday, October 2, from 9 a.m. to 1 p.m., on the 7th level of the parking garage at the Houston Museum of Natural Science.

Bouquet of Coneflowers
Coneflowers
Creative Commons License photo credit: Randy Son Of Robert

Twice a year we have a sale where we carefully select just the right plants for you to put in your garden to attract butterflies and their offspring. How do you go about attracting butterflies and their offspring? Well, first of all, you need lots and lots of nectar plants, the more variety the better. The best nectar plants are those with small tubular flowers arranged in clusters, sometimes with brightly colored petals that serve as a target to alert the butterflies that, “Hey! There’s food over here!” Butterflies survive on a liquid diet because of their specialized mouthparts, collectively called a proboscis. It looks like a coiled straw which they unravel to poke down inside flowers and consume the sugary liquid. Some examples of excellent nectar plants are Coneflower (Echinacea sp.), Black and Brown Eyed Susan (Rudbeckia sp.), Native Gayflower (Liatris sp.), Lantana, Verbena, Porterweed (Stachytarpheta sp.), Salvia, Heliotrope, Mexican Sunflower (Tithonia) and many, many more.

Did you think I forgot to mention their offspring? Of course not, that is my favorite part of butterfly gardening! Let’s back up for a minute so you can see the big picture. A butterfly’s life is comprised of four stages. In each stage the creature looks totally different. The whole lifecycle is called complete metamorphosis (meta means change, and morph means form). The first stage is the egg, which was laid by its thoughtful mother on a very important plant called a host plant. (Did you know butterflies are really good botanists? The story gets even weirder. They can tell plants apart by tasting them with their feet!) When the egg hatches, a caterpillar (otherwise known as a larva) crawls out and immediately eats the egg shell. Then, the caterpillar looks around and wonders, “What else is there to eat around here?” Well, little friend, you are sitting right on top of it. The host plant is the food, the life support, for the caterpillar. Without host plants we would not have butterflies!

Monarch Butterfly (Danaus plexippus) monarch-butterfly_2
Monarch Butterfly
Creative Commons License photo credit: mikebaird

Each type of butterfly corresponds to a different type of host plant. For example, the well known Monarch butterfly only lays its eggs on the Milkweed plant (Asclepias sp.). The Monarch caterpillars will not eat Parsley or Dill, but you know who will? The Black Swallowtail, that’s who. Other host plants that attract our native butterflies are: citrus species, rue (Ruta graveolens), and wafer ash (Ptelea trifoliate) for the Giant Swallowtail; Dutchman’s pipevine (Aristolochia fimbriata and A. elegans) for Pipevine and Polydamas Swallowtails; spicebush (Lindera benzoin) and sassafras (Sassafras albidum) for the Spicebush Swallowtail; sennas (Cassia sp.) and partridge pea (Chamaecrista fasciculate) for Sulphurs; and passionvines (Passiflora sp.) for the Gulf Fritillary.

The third stage of metamorphosis is the chrysalis (or pupa), which is what the adult butterfly (the fourth and final stage) emerges out of.

When you combine nectar and host plants in your landscape you will not only increase your chances of seeing butterflies, but you can also have the experience of witnessing the amazing process of metamorphosis first hand. If you don’t want to see plants that are chewed up, you can omit the host plants, or place them behind other plants, however, watching a butterfly lay eggs and watching caterpillars grow is pretty cool.

We will have the majority of the plants mentioned above at the plant sale, plus many more (a “complete” list is on the website). The selections we have made are for growing in Houston and the surrounding areas, a lot being native plants. You can also learn about gardening for butterflies at the sale from our knowledgeable staff and volunteers. Hope to see you there!

Here are some tips for attending the plant sale:
1. Get there early. Don’t wait and expect to have a lot to choose from an hour before we close.
2. We will have wagons for customers to cart their plants to their cars, but if you have your own, bring it.
3. We take cash, check and credit cards.
4. The lines are long, but look at it as a time to make new friends or learn something new.