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!

Butterfly Gardener Alert!

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 April 10.

She Was Completely Transparent With Me
Creative Commons License photo credit: Randy Son Of Robert

Got butterflies? Probably not, if your garden suffered freeze damage over the past few months. After this unusually long and cold winter, many of us have lost plants, especially species that are more tropical and not adapted to freezing temperatures.

But now that winter is finally behind us, it’s time to replant! Butterfly gardeners won’t want to miss the Cockrell Butterfly Center’s Spring Plant Sale. It’s happening soon:  Saturday, April 10, 2010 from 9 a.m. to 1 p.m., on the 7th level of the parking garage at the Houston Museum of Natural Science.

Some of you may be seasoned butterfly gardeners, but others may be asking, “How DO you ‘garden’ for butterflies?” It’s quite simple.   For a successful butterfly garden you need two types of plant:  nectar and host plants.

Mix of flowers

Coneflowers and Rudbeckias
Creative Commons License photo credit: Per Ola Wiberg ~ Powi

Thanks to their specialized mouthparts – a long, thin, straw-like proboscis – adult butterflies can only consume liquid food.  The blooms of nectar plants produce a sugary liquid (nectar) that butterflies sip to give them the energy to fly, mate, and produce eggs.  Most nectar plants have colorful flowers borne in showy clusters.  Some examples of good nectar plants for our area are Porter Weed, Echinacea (Purple Cone Flower), Zinnias, Rudbeckia (Brown and Black-eyed Susans), Monarda (Bee Balm), Lantana, Salvias, Eupatorium (Mistflower), Cuphea, Buddleia (Butterfly Bush), and Tithonia (Mexican Sunflower), among many others.

Green Papilio polyxenes caterpillar

Eastern Black
Swallowtail Caterpillar
Creative Commons License photo credit: cyanocorax

In contrast to the adults, baby butterflies, aka caterpillars, have chewing mouthparts and eat leaves.  Many butterflies are quite choosy in their caterpillar stage, and can only survive and grow on specific plants, which we call host plants.  For example, Monarch caterpillars will only eat Asclepias (Milkweed); they cannot and will not eat anything else.  Female butterflies seek out the appropriate host plants for their babies when they are laying eggs.  Some host plants that can be included in your butterfly garden are Asclepias (for Monarchs and Queen Butterflies); Passionvines (for Gulf Fritillaries and if you’re lucky, Zebra Longwings); Citrus and Rue (for Giant Swallowtails); Dill, Parsley, and Fennel (for Black Swallowtails); Aristolochia aka Pipevine (for Pipevine and Polydamas Swallowtails); and Cassia aka Senna (for Sulphur Butterflies).  If you see caterpillars eating these plants, rejoice!  You will soon have lots of beautiful butterflies coming to your nectar plants.

Some of you may think you don’t want caterpillars eating away in your garden.  If so, you can avoid host plants and include only nectar plants.  However, you’ll get more butterflies if you plant both.  We predict that soon you’ll be treasuring every caterpillar!

Many of the nectar and host plants listed above will be available at our sale.  We strive to provide butterfly-attracting plants that are either native or naturalized in Texas, and that perform well in the Houston area.  Our sale is also a good place to learn more about butterfly gardening.  Several experts will be on hand to answer questions and to help you choose plants.


Plant Sale! At the Cockrell Butterfly Center from HMNS on Vimeo.

So save the date:  Saturday, April 10, from 9 a.m. to 1 p.m.  Come early, the plants go fast!

Insects and Orchids: An Evolutionary Journey

I absolutely love orchids! I mean who doesn’t, really? They are my very favorite flower in the whole world. I can literally stare at them for hours and not get tired of them. I love to photograph them; I even had them in my wedding! I love their colors, their shapes, there is really no flower quite like the orchid.

Well, if you love these flowers as I do, I’ve thought of another reason for you to love insects! We would not have the amazing shapes, the striking colors, or the unique fragrances from orchids if it weren’t from our amazing little friends!

Orchids are an ancient flower – appearing some 80 million years ago, during the time of the dinosaurs – much older than scientists first believed. They flourished, as many organisms did, after the big extinction and began to figure out how to best survive in this new world. They can grow on every continent except for Antarctica and in almost every type of habitat. They can grow as epiphytes, attached to trees or shrubs, lithophytes, attached to rocks, or they can be terrestrial like most other flowers. They also figured out, because plants are very smart you know, that cross pollination, as opposed to self pollination, is the best way to survive. What is the best way to cross pollinate? With insects of course. So began an intricate process of co-evolution between these amazing flowers and their insect counter-parts.

Co-evolution can be defined simply as the change of a biological object over time that is triggered by the change of a related object. So, as the insects changed, so did the orchids which were dependent upon them. This has led to an incredible amount of diversity in the 25-30,000 species of orchids that exist today. Charles Darwin studied orchids and their relationship with insects; he developed this theory of co-evolution based on his findings. He introduced the theory of plant and insect interactions in his book, On the Origin of Species. Later, he published Fertilisation of Orchids, which explained in detail the complex relationships between these flowers and the insects that pollinate them and how this led to their co-evolution.

A Cocytius antaeus, the new world equivilant of the
Xanthopan morgani.

Today, this can be seen more than ever with some extremely unique orchids and their very interesting, and sometimes weird, ways of attracting insects. One of the most compelling pieces of evidence of this co-evolution is Angraecum sesquipedale or, Darwin’s Orchid in Madagascar. Darwin noticed that this orchid had an extremely long spur, so long that only an insect with a very long proboscis could reach the nectar inside. He actually predicted that there was an undiscovered moth out there with a foot-long proboscis that could pollinate this orchid. Well, he was right, and now we have Xanthopan morgani or the Morgan’s sphinx moth. This incredible moth was not discovered until 1903, but proved Darwin’s theory and was originally named Xanthopan morgani praedicta in honor of his prediction. The moth has an unbelievably long proboscis which can reach down into the flower to retrieve the precious nectar. In doing so, the moth rubs its head against the pollen producing organ of the plant and transfers the pollen to the next flower it drinks from.

(un)natural encounter
Creative Commons License photo credit: avmaier

Many other orchids use specific fragrances to lure insects. Some use sweet fragrances to attract certain bees and wasps, and others, putrid smells to attract flies. These happy insects are rewarded for their pollination with yummy nectar. Others use striking colors that flying insects can’t resist. Still others, about 1/3 of all orchids, produce no nectar. These have come up with some pretty tricky methods of attracting insects. These are some of the most specialized orchids of all. Some mimic the smell of food. Flying insects approach the flower and crawl all over it looking for the nectar. It is not until they are covered in pollen that they give up and move on to the next one, transferring the pollen in their search for food.

Even more deceiving are the orchids that use sex pheremones to attract unsuspecting pollinators. These orchids are amazing. They actually mimic the female bee or wasp visually, often using the same colors and tufts of hair. They give off a chemical that smells identical to the pheremone that the female insect would give off. The poor males climb on the flower, actually try to mate with it (sometimes leaving behind sperm) and move on to the next, spreading the pollen. What a smart flower! Watch this video to see a great example of this type of orchid.

Stemless Lady-slipper
Creative Commons License photo credit: *Micky

One last amazing orchid/insect relationship. The lady’s slipper orchid is a very unique looking flower. With a pouch-like structure, it resembles a pitcher plant, which is a known insect-eating plant. The pitcher plant uses its pouch to lure in insects which fall in and are digested inside. The slipper orchid, however, has a much more benevolent agenda. The pouch does lure insects, they do fall down inside, but they do not meet their doom there. The pouch is too small for the insect to stretch its wings so they cannot fly out. The only way out is to climb a ladder of hairs on the back. The insect must squeeze past where the pollen is kept to get away. They either leave with the pollen, or leave another plant’s pollen there, tricky tricky!

So, you see, if you’ve never thought of plants as intelligent, you may want to think again. Exquisite, exotic, luxurious, stunning, elegant, whatever term you use to decribe orchids, you can now add intelligent and highly evolved. I hope this gives you a whole new respect for these famous flowers, and the bugs that make them what they are!

If you like orchids and want to learn more about them, don’t miss the Houston Orchid Society’s upcoming Show and Sale, which will be held at the museum this year. It’s free! Saturday and Sunday only, April 17 & 18. For more info, visit our web site.

Plant Sale for Butterfly Lovers this Saturday, April 4 at HMNS!

duranta
 Duranta Plant
Creative Commons License Photo credit: Jayjayc

This Saturday, April 4, the Cockrell Butterfly Center will hold its highly anticipated spring plant sale, featuring a great selection of plants that are guaranteed to bring butterflies to your garden.  The sale will be held on the sundial plaza just outside the museum’s main entrance, beginning at 9 a.m. and ending at 1 p.m.  Come early to get the best selection – plants go fast! 

We feature both nectar plants (to attract a selection of adult butterflies) and several host plants (food plants for the baby butterflies, aka caterpillars).  Of course experienced butterfly gardeners know that you need both to attract the maximum number of butterflies.  But we can also recommend the best starter plant or plants for anyone just wanting to get their antennae wet for the first time…! 

Knowledgeable and enthusiastic horticulturalstaff and docents will be on hand to help you make your decisions.  This is the perfect time of year to get plants in the ground – and the butterflies are just beginning to show up en masse (eager to lay their eggs to start a new generation) – so get ready for them by coming to this sale!

A quick list of nectar plants includes (among others) – several species of salvia, verbena, cone flowers, duranta, lantana, porter weed, and many more.   Available host plants include Brazilian pipevine, Mexican milkweed, cassia, and citrus.   We also have a few “just for fun” plants – come and see!

The butterflies will thank you for it.