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. 

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 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.


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.

Why no tropical milkweed at the Cockrell Butterfly Center plant sale this year?


Aslepias curassavica

We are sorry to disappoint monarch enthusiasts, but the Cockrell Butterfly Center has decided not to sell tropical milkweed (aka Mexican milkweed, Asclepias curassavica) any more. Instead, we will have a limited quantity of native milkweeds for sale. Recently, biologists studying monarchs have discovered that tropical milkweed may be a factor in the spread of a parasitic infection that attacks monarchs. The infection is called Oe (short for Ophryocystis elektroscirrha) and is transmitted by spores that fall from an infected female’s body onto the hostplant when she lays her eggs. The hatchling caterpillars eat the spores along with the leaves, and become infected themselves. After a generation or two or three, the infection level becomes so high that the butterfly dies (sometimes in the caterpillar stage, sometimes in the pupal stage, and sometimes as the adult).

This could happen with any milkweed – the problem with the tropical species is that it does not senesce (die back) in Houston’s mild winters but is perennial, growing throughout the year. In contrast, native species die back to the ground in the winter, and when they regrow in the spring they are spore free – so the infection cycle is broken.

Also, researchers have found that some monarchs in the southern part of the USA don’t bother to migrate if they have milkweed available. These year-round residents have been found to have very high levels of Oe infection, because they are mostly using the tropical milkweed species generation after generation. While this probably doesn’t greatly impact the migration as a whole, we don’t want to contribute to the local spread of the disease.

If you do already have tropical milkweed, one solution is to cut it back severely a couple of times a year. Even better is to remove the tropical variety and switch to native milkweed species. Unfortunately, so far these are not widely available in the nursery trade and are not as easy to grow as the tropical variety!

Aslepias viridis

Aslepias viridis

We are all learning and struggling to do our best for the butterflies. This year we will have a limited quantity of two native species at our spring plant sale: Green Milkweed (Asclepias viridis) and Antelope Horns Milkweed (Asclepias asperula).


Our next plant sale will be Saturday, March 28, 2015 from 9 a.m. to noon, or until we sell out. It will be located in its usual spot on the 7th level of the Museum parking garage. We hope you will try growing native milkweeds, and please let us know how it goes for you!

Tired from a long journey, faded monarchs seek homes for the next generation

My friends Bob and Bev photographed this very faded, tattered female monarch flying around the milkweed plants in their backyard near the Museum last week. The butterfly is a migrant from Mexico, looking for places to lay her eggs as a last hurrah before she dies.

Detail of a healthy monarch’s wing

The monarch we found with faded, damaged wings

The monarch we found with faded, damaged wings

She must be very tired!

Last fall, she flew from somewhere in eastern North America all the way to central Mexico, where she spent the winter mostly in hibernation. A few weeks ago, she and the other overwintering butterflies, sensing the lengthening days and warming temperatures, left the shelter of the sanctuary’s trees and headed back north to complete the journey. They are just now getting to Texas.

This old girl’s eggs will hatch and — if they have enough milkweed — the caterpillars will mature and pupate. Then, when they emerge as adult butterflies, at least some of them will continue the journey north. By July, monarchs will have reached the northern limit of their range. These summer generations don’t live as long, and don’t travel nearly as far.

P1070759If you see worn and faded monarchs at this time of year, they are almost certainly migrants returning from their winter in Mexico. You can help them to fulfill their “purpose” by providing nectar for their last few meals, and more importantly, milkweed for the new generation. These returning migrants will only last a few days now that they’ve gotten here — they are on their last “wings” after nearly nine months of life, and at least 2,000 miles of travel.


A healthy Monarch Butterfly