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.

Mark Your Calendars for these events happening at HMNS 3/23-3/29

Bust out your planners, calendars, and PDAs (if you are throwback like that), it’s time to mark your calendars for the HMNS events of this week! PlantSaleSpring2015_Facebook_cover

Behind-the-Scenes Tours
Tuesday, March 24
6:00 p.m.
Samurai: The Way of the Warrior
Witness the exquisite objects related to the legendary Samurai warriors of Japan in the special exhibition Samurai: The Way of the Warrior. Museum master docents will lead you through the collection that includes full suits of armor, helmets, swords, sword-hilts, and saddles, as well as exquisite objects intended for more personal use such as lacquered writing boxes, incense trays and foldable chairs
Wildlife Photographer of the Year
Featuring 100 awe-inspiring images, from fascinating animal behavior to breathtaking wild landscapes,Wildlife Photographer of the Year harnesses the power of photography to promote the discovery, understanding and responsible enjoyment of the natural world. Tour this visually stunning exhibition with our resident photographers David Temple and Janell Nelson.

George Member Night
George Observatory
Friday, March 27
7:30 p.m.
Enjoy an evening under the stars at the George Observatory inside Brazos Bend State Park. Expert astronomers are available to let Members look at a variety of celestial objects through the Observatory telescopes, as well as privately owned telescopes. Viewing is always weather dependent. State Park entrance fees apply.

Spring Plant Sale
Saturday, March 28
9:00 a.m. – 12:00 p.m. (or until sold out)
7th level of the parking garage
Attract butterflies to your home garden!
Interested in Butterfly Gardening? The perfect opportunity to get started awaits you twice each year, at the Cockrell Butterfly Center’s semi-annual plant sales! Once in spring and once in fall, we offer a wide variety of nectar plants for butterflies and host plants for their caterpillars. Plenty of experts are on hand to answer your butterfly gardening questions and help you to create the perfect butterfly habitat – right in your own backyard.

Wyland Foundation’s Clean Water Mobile Learning Experience
Saturday, March 28 & Sunday, March 29
National Tour Stop in Sugar Land During Regular Museum Hours!
Free Admission
This exclusive tour stop of the water mobile will increase visitors knowledge of the function of watersheds and create a broader understanding of the impact communities have on these systems and our ocean. Join the Clean Water Challenge Task Force and solve the mystery behind disturbances in the health of our nation’s water habitats via a 4D theater experience and other hands-on science activities.

Water Mobile Event
Saturday, March 28
9:30 a.m. to 4:30 p.m.
Join us for public tours of the Water Experience and visit related display tables from area conservation groups.

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

Asclepias_curassavica_(Mexican_Butterfly_Weed)_W_IMG_1570

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).

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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!