A Staple for Butterfly Exhibits: The Rice Paper

One of the most distinctive and easily recognizable insects in the Cockrell Butterfly Center is the rice paper butterfly (Idea leuconoe), also known as the paper kite and the large tree nymph. All these common names allude to the rice paper’s characteristic slow, graceful, and sometimes floppy flight. These butterflies make great, showy additions to butterfly exhibits and are therefore a widespread staple, found in most live butterfly displays. Rice papers are native to the forested regions of Southeast Asia.

idea leuconoe dorsal

Rice papers make great additions to butterfly exhibits.

Rice papers are related to the well-known monarch, both belonging to the subfamily Danainae and known to be distasteful to most avian predators by sequestering chemicals in their bodies from their larval food plants. Monarch caterpillars eat milkweed to become unpalatable. Similarly, rice paper caterpillars feed on the milkweed relative, Parsonsia, to become distasteful. The monarch’s striking black-on-white and yellow coloring serves as a warning to potential predators. Rice paper larvae have a similar flashy coloration: black and white stripes with red spots.

Contrasting colors on the caterpillars warn predators to stay away.

Contrasting colors on rice paper caterpillars warn predators to stay away.

The rice paper life cycle begins with the female butterflies laying eggs on their host plant, Parsonsia. The eggs are small and cream-colored, usually laid on the underside of leaves. The eggs take about five days to hatch into tiny black-and-white striped caterpillars. The caterpillars first feed on their eggshell before directing their appetite to the Parsonsia leaves. The newly hatched larvae are too small to chew all the way through the thick leaves, so they create a circular trench as they eat the leaf epidermis. As they are eating they will extend their bodies and regurgitate yellowish foam distal to the chewed area. They continue this behavior until they have completely surrounded themselves in a ring of foam. This foam has been found to act as an effective ant repellent; ants will not cross the barrier. As the caterpillar grows, it “molts” five times in stages called instars. First through third instar caterpillars will exhibit this foaming behavior. Fourth and fifth instar caterpillars do not use regurgitated foam to repel ants.

Stages of caterpillar development.

Stages of caterpillar development. The top-right image shows a caterpillar inside its ring of ant-repelling foam.

It takes the caterpillars about two weeks of munching on leaves to reach pupation size. At this point, the caterpillars will find a safe spot to hang and form a “J” shape. They will then molt to reveal chrysalids that take about two days to completely dry. The chrysalids are a beautiful, shiny, metallic gold with black spots and swirls. Approximately 10 days later, the chrysalids pop open to reveal a brand new butterfly. The wet butterfly allows its crumpled wings to unfurl. A couple of hours later, the butterfly uses its newly dry wings to take flight and awe and educate museum visitors. 

King Richard III, Rediscovered: Forensic engineer to hold reburial lecture

The remains of King Richard III, the last English king to die in battle, were discovered under a parking lot and identified in 2013 using DNA, radiocarbon dating and the identification of his distinctive curved spine by a team from the University of Leicester. What science revealed from Richard’s skeleton has triggered a revival of scholarship regarding his reign.

Dr. Sarah Hainsworth, Forensic Engineer on the Richard III Project, will visit the Houston Museum of Natural Science Tuesday, April 21 to discuss the project’s findings and how history, archaeology and genetics were woven together to learn more about Richard III. Her lecture, “Richard III Rediscovered,” begins at 6:30 p.m.Richard III

Following the lecture, a real-life King Richard will join us for a festival featuring food, drink, dance and music inspired by the Renaissance. The event is cosponsored by the Houston Society of the Archaeological Institute of America.

For more fascinating insights into the Richard III Project and reinterment, check out “From the Trenches,” the blog of the AIA, Houston Society. Excerpts below:

Richard III’s “Rebirth” and Reburial

 Richard III – Defiled in death, reviled in history…today, reburied with pomp and circumstance. image001

On March 26, 2015 momentous events took place in Leicester, England as Richard finally received a burial fit for a king, 530 years after his death on the battlefield. A processional lead by armored knights on horseback winded through the streets of Leicester to the cathedral for a service that included the Archbishop of Canterbury, descendant Benedict Cumberbatch, and descendants of both the noble from the Wars of the Roses.

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Face to Face with History

With the discovery of the remains of King Richard III, a unique, exciting opportunity presented: the chance to discover Richard’s appearance. Perhaps at no other time in history, has it been possible to really know about the appearance of a ruler. The historian has textual evidence and artistic representations. These depictions are diluted through the opinions of the writer or the painter, often serving propagandistic purposes. The most famous portraits of Richard III, depicting him as dark-haired and steely eyed were painted 25 to 30 years after his death. However, archaeology has tools at its disposal that help to create a clearer portrait.

Richard III (Physiology & Experimental Archaeology)

One of the fascinating discoveries of the project was the physical evidence from the bones. For over 500 years, detractors (Shakespeare among the most famous) portrayed Richard III as a twisted, deformed tyrant. The remains that were found of the king put to rest the story of his skeletal deformities – it was immediately and dramatically apparent that Richard did indeed suffer from scoliosis.image004

New questions now emerged: could medieval armor be made to fit a person with that degree of scoliosis, how could a person with such deformities fight ferociously in battle, could he sit astride a horse? Anecdotal evidence mentions his fighting ability, his horsemanship, and his graceful dancing. Could these stories be true? Enter the field of experimental archaeology and physiology to work to arrive at answers. Today, we share the story of a young man who has the same type of scoliosis as Richard III. Researchers began working with him and the results are fascinating.

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.

It Takes a Village ….A Milkweed Village

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As the obligate host plants for monarch caterpillars, milkweeds are a staple in any butterfly habitat garden. However, milkweed is not just for monarchs! Many other insects call the genus Asclepias home, giving rise to the concept of a “milkweed village.”

Milkweed plants produce bitter tasting toxins called cardiac glycocides, and insects that eat milkweeds have evolved to use these to their advantage, sequestering the toxins in their bodies to protect themselves from predators. Most, if not all milkweed-eating insects have markings of black and orange or yellow, a type of aposomatic coloration that warns predators of their horrible flavor. If a predator such as a bird, lizard, or spider were to eat one of these insects, it would spit it out. The next such insect would be avoided, as its coloration would remind the predator of its foul flavor.

Most butterfly gardeners have encountered the bright yellow oleander aphid, Aphis nerii, which congregates on the new growth, flowers, and developing seed pods of milkweed plants. Aphids are phloem feeders, meaning that they suck the sap, along with the toxins, out of the plant’s vascular tissue.

Ladybug larva

Ladybug larva

The presence of these aphids on milkweed attracts a number of predatory insects. Ladybug larvae and adults (Hippodamia spp. and others) are important predators of milkweed aphids. Other small beetles such as mealybug destroyers, Cryptolaemus montrouzieri, and scale destroyers, Lindorus lopanthae, eat aphids along with other small sap-feeding insects. These beetles are interesting creatures in that their larval stage looks just like their namesake (i.e., mealybugs and scale, respectively).

scale destroyer larva2

Scale destroyer larvae

The maggot-like larvae of syrphid flies also eat aphids, sucking their bodies dry. Syrphid pupae look like little brown or tan teardrops. If you notice these on your milkweed plants, leave them in place to ensure another generation of these beneficial flies.

Syphid fly pupa

Syrphid fly larva

Tiny parasitic wasps such as braconids lay their eggs in aphids’ bodies. The wasp larvae feed on the inside of the aphid until they pupate, then exit as an adult wasp through a tiny hole in the aphid’s exoskeleton. The leftover brown “shell” is called an aphid mummy. These mummies are a good sign that your aphids are being parasitized. Don’t worry, these wasps don’t harm monarch caterpillars.

aphid mummy

Aphid mummies

With all of these great beneficial insects around, I hardly had to spray our milkweed crop at the museum with any insecticidal soap this year. However, if the aphid population on your milkweeds gets to be overwhelming, the best way to knock them back is to spray them off the plants with a sharp stream of water. Try to avoid damaging or knocking off any beneficial insects in the process.

Other “pests” of milkweed plants include the milkweed leaf beetle, Labidomera clivicollis. These chunky, orange and black beetles and their larvae feed on milkweed leaves.

Milkweed Beetle (Wikipedia)

Milkweed Beetle (Wikipedia)

Large milkweed bugs, Oncopeltus fasciatus, are also common in the southern United States. These oblong-shaped, sap-sucking true bugs are orange and black and mostly feed on the developing seeds, flowers and nectar of milkweed plants. They don’t usually cause much damage.

Now we come to the most familiar milkweed inhabitant – the monarch butterfly, Danaus plexippus. As we all know, monarch caterpillars eat voluminous quantities of milkweed leaves, and display the textbook aposomatic coloration of white, black and yellow stripes. Their chrysalids, or pupae, are a gorgeous jade green with gold lines and spots.

monarch

Here in Houston we sometimes encounter another milkweed visitor – the queen butterfly, Danaus gilippus. Queen caterpillars look very similar to the monarch, but they have three pairs of tentacles instead of the monarch’s two. Their chrysalids are also similar, but are a bit smaller and may sometimes be a pale pink rather than green.

Like everything else, monarchs are part of the food chain, and are preyed upon or parasitized by a number of different organisms. One of their most prevalent parasites is a tachinid fly, a gray, hairy species about the size of a house fly. An adult fly female will lay her eggs on a monarch caterpillar and when they hatch, the maggots burrow inside. The maggots live inside the caterpillar, eating its tissues, until they are ready to pupate. At that point they crawl out of the caterpillar and fall to the ground, where they pupate in the soil The maggots often leave the caterpillar after it has pupated, leaving a trail of slime that dries up and looks like white strings hanging from the chrysalis. These strings are tell-tale signs of a tachinid fly infestation.

Tachinid fly larva emerging from monarch caterpillar.

Tachinid fly larva emerging from monarch caterpillar.

Assassin bugs, Zelus sp., are frequent visitors to milkweed plants. This true bug will stab monarch caterpillars with its rostrum or beak, paralyzing the victim and liquefying its insides, making it easier to consume.

Vespid wasps are another important predator of monarchs. The familiar large red wasps, Polistes carolinus, and the smaller yellow and black European paper wasp, Polistes dominulus, both hunt caterpillars as food for their own hungry larvae. Once a wasp finds a host plant with caterpillars, she will come back regularly to check for more, especially in the summer months when wasps are the most active. This can be upsetting to butterfly gardeners. To protect your caterpillars from these all-too-efficient predators, place a screen such as a pop up or mesh laundry hamper between them and the wasps.

Polistes carolina  Photo by Val Bugh

Polistes carolina Photo by Val Bugh

 

Polistes dominulus

Polistes dominulus

Finally, a parasite of notable concern that specifically affects monarchs (and also queens) has emerged on the scene of butterfly gardening. This protozoan parasite, Ophryocystis elektroscirrha, commonly known as Oe, begins with a dormant spore, usually deposited by an infected female monarch as she lays her eggs on a milkweed. When the caterpillars hatch and begin to eat, they consume the Oe spores along with the leaf. Once inside a caterpillar’s gut, the spores become active and reproduce several times. When the butterfly emerges from its pupa, it is covered in dormant Oe. spores, giving rise to the next generation of infected monarchs. Mildly infected butterflies may show no sign of infection but as Oe levels build up, they eventually cause problems such as weakness, deformity, and even death.

OE Life Cycle (Monarchparasites.org)

OE Life Cycle (Monarchparasites.org)

The annual migration to Mexico each fall helps to weed out infected butterflies, which are usually too weak to make the long trip and die along the way. However, some monarchs don’t migrate and may stay in the Houston area all winter long. In the south, butterfly gardeners primarily grow tropical milkweed, Asclepias curassavica, which unlike the native milkweeds does not die back to the root in the fall. Oe spores can remain viable on the leaves of this perennial species for some time, infecting the next generation of caterpillars that eats them. As this situation repeats, it can cause populations of severely infested monarchs. We therefore encourage butterfly gardeners to cut back their tropical milkweed every spring after the first generation of monarchs arrive and eat the milkweed down, and then again in the fall before or during the migration, so that the butterflies will be encouraged to migrate and not overwinter here.

Spiny soldier bug nymph eating a monarch caterpillar. (Photo by Dan McBride)

Spiny soldier bug nymph eating a monarch caterpillar. (Photo by Dan McBride)

With all of these challenges, it’s no wonder that only five to ten percent of monarch eggs make it to adulthood. Keep in mind however, that monarchs are an important part of the food chain and without their survival and natural demise, our native ecosystem would not be as diverse as it is. In any case, human interactions with the environment have caused the most damage to monarch populations – huge amounts of monarch habitat has been lost due to the expansion of agricultural land and use of Roundup Ready crops. Planting butterfly-friendly gardens, especially if they include milkweed, can help mitigate this loss of habitat.

You can do your part by attending our fall plant sale at the Houston Museum of Natural Science. Stock up on the nectar plants that monarchs need to fuel their migration as well as host plants for native butterflies.

The sale will be held on Saturday, October 11th from 9:00 a.m. until noon (or until plants are gone), and will take place on the 7th level of the museum parking garage. Remember, the early bird gets the larva, so to speak, and don’t forget your wagon!