Monarchs want YOU to plant milkweed: Butterfly-friendly plants for sale at HMNS

The butterflies need your help! With urbanization, and a host of other factors, monarch butterflies are at risk of not finding places to lay their eggs. So why not help while improving the butterfly traffic through your garden with a butterfly-seducing plant from our biannual plant sale?

Milkweed plants in the genus Asclepias are extremely important for butterflies, especially monarchs. While the blooms provide copious amounts of nectar for many different butterflies, the foliage is an essential part of the monarch butterfly’s life cycle. Milkweeds are the only plant monarch caterpillars will eat. In other words, they can’t live without it!

Native milkweed plants grow along roadsides and in open fields. The butterflies find them by honing in on their volatile chemicals and finally locate the exact plant by “tasting” nearby plants with special receptors called chemoreceptors on their feet. Once a gravid female (one who has mated and is ready to lay eggs) finds a good milkweed plant, she will lay eggs on it — and the miraculous process of metamorphosis has begun!

There are about 100 species of Asclepias in the United States, and over 30 in Texas — but monarchs seem to prefer some of them over others. According to a study by Linda S. Rayor, described in The Monarch Butterfly: Biology and Conservation, when given a choice, monarchs prefer to lay eggs on other species of milkweed over the native species Asclepias tuberosa.

Butterfly - Tropical Milkweed

Besides being a host plant for Monarch larvae, Tropical Milkweed (A. curassavica) is a great nectar source for many butterfly species!

Why? Different Asclepias species contain different cardenolide concentrations (cardenolides are the chemicals in the milkweed leaves that taste bitter). As they eat, the caterpillars store these toxic chemicals in their bodies and thus become distasteful to their predators. A. tuberosa has been found to contain low amounts of cardenolides compared to most other species of milkweed. Although it is unclear how monarchs “know” this, they do not usually use A. tuberosa as a host plant.

Several other native milkweed species, however, are great host plants for the monarch. Asclepias asperula (Antelope Horns), A. viridis (Green Milkweed), A. incarnata (Swamp Milkweed) and A. oenotheroides (Zizotes Milkweed) are some of the more commonly found milkweed plants in our area that monarchs use as host plants.

Unfortunately, most of the native milkweeds are hard to find in plant nurseries. One reason is that their seeds require moist stratification to germinate, and even with this pretreatment, germination can be splotchy. Furthermore, young plants of A. asperula, viridis and oenotheroides take several seasons to establish their thick taproots, and can be hard to transplant.

On the bright side, most of the native milkweeds, except for A. incarnata, are drought tolerant and can handle being mowed. Swamp milkweed obviously likes moist soil. All milkweeds grow best in full sun.

Butterfly - Green Milkweed

Asclepias viridis, Green Milkweed

Most gardeners are familiar with tropical milkweed, or Asclepias curassavica. This plant is commonly available in local plant nurseries and attracts butterflies like a magnet! Its bright orange and gold flowers are irresistible to many butterflies, and the high levels of cardenolides in its foliage make it especially sought out by female monarchs looking for a place to lay their eggs. Although it originates in more tropical climes, it is relatively cold hardy and will usually come back from the base of the plant after a freeze. It is also easy to propagate from seed, and in fact will sometimes seed out (make more of itself) in a garden.

So tropical milkweed seems like the ideal plant. However, one issue with this species is that it is not native to our area and does not exhibit the same characteristics of our native milkweeds, all of which die back to the ground in winter. This perennial habit seems advantageous, but it can be a problem for a couple of reasons. Because it has leaves year-round, it may encourage monarchs to overwinter locally instead of migrating to Mexico. It can serve as a host for a disease that affects monarchs, called Ophryocystis elektroscirrha, or simply O.e. This disease is caused by a protozoan parasite and is spread in the dormant stage of its lifecycle as a tiny spore.

These spores are typically on the abdomen of an infected monarch butterfly and can be spread to her eggs or onto the milkweed plants themselves when a female lays eggs. Then, when the caterpillars hatch out of the eggs, they consume the spores that lie on their empty egg shells or on the leaves around the egg and become infected.

Over a few generations, the parasite load can build up to high enough levels that it impacts the butterfly’s survival. Depending on the severity of the infection, the disease can make the caterpillars look a bit grayish and their stripes not as distinct. When the caterpillars pupate, their chrysalis may look brownish or spotted. The butterfly inside may emerge but have problems, such as an enlarged, gray abdomen and weak, faded wings.

Sometimes they emerge and look healthy, but secretly harbor O.e. spores on their abdomens. Other times they don’t emerge from the chrysalis at all, or get stuck while trying to come out.

So what is my point? I thought we were talking about milkweed plants! ;-) The reason this is important is because O.e. spores persist on the leaves of the tropical milkweed plants, waiting for an unsuspecting caterpillar to munch them up. To break this cycle, we recommend cutting your tropical milkweed plants back after a monarch generation has stripped their leaves, especially in the spring and fall. A simple pruning of the plant’s stems about six inches from the ground will get rid of any remaining spores and will sprout new growth in no time.

Some other closely related plants that monarchs will use as a host are Gomphocarpus physocarpus or “family jewels” milkweed, and a species of Funastrum or twinevine. Gomphocarpus is a lot like A. curassavica in that it doesn’t lose its leaves in the winter so it also needs to be cut back periodically to keep it from spreading O.e.

Butterfly - Funastrum cynanchoidies flower

Funastrum cynanchoidies flower

Funastrum or twinevine is an interesting climbing plant native to south Texas and Mexico. The plant is not very impressive looking until the summer, when it puts on beautiful balls of milkweed-like flowers that are great nectar sources for many kinds of butterfly. Another good thing about it is that when monarch caterpillars have stripped all your milkweed plants of their leaves and are still hungry, they will eat the leaves of Funastrum.

With their habitat dwindling due to urbanization, the use of Round Up ready crops, shrinking right-of-ways due to intensive agricultural practices and other factors, monarch butterflies need all the help they can get. The take-home message today is PLANT MORE MILKWEED! (please)

For milkweed and other awesome butterfly host and nectar plants, come visit us at our biannual Spring Plant Sale on Saturday, April 5th from 9 a.m. until we sell out! We are located on the 7th level of the Museum parking garage. Parking is free if you spend $30 or more!

Come early, the plants go fast!

Beautiful Spring-time Butterflies!

Spring-time is almost here and the butterflies will soon be fluttering all around town.  I have actually seen a lot already, but we do live in Texas, so that’s not a surprise.  Since I work in an exotic butterfly house, I definitely have my favorite exotic butterflies, but I also have a few favorites that are here in Texas as well.  Many of you may be expecting me to write about the monarch, Danaus plexippus, but I thought I would write about some different, but still very common ones that we find around here in Houston.  If you are interested in monarchs, please check out Nancy’s blog - all about monarch migration.

Morning Butterfly
Creative Commons License photo credit: Joel Olives

The Gulf Fritillary, Agraulis vanillae, is a butterfly that frequents Houston quite often.  Its caterpillars feed off of every single part of the passion vine plant, which make them poisonous and nasty-tasting to predators. 

A couple of summers ago, I had tons of these caterpillars on my passion vine plant.  The caterpillars have large spines along their body with an underlying bold purple, orange, and black coloration, serving to warn predators of their danger!  I’m sure many of you have seen this bright orange and black butterfly fluttering around nectar plants such as Lantana, Zinnia, Coneflowers, Butterfly Bush, and many others. 

One of the most distinct characteristics of the Gulf Fritillary is the spectacular silvery, almost mirror looking, spots on the underside of the wings.  The males and females look very similar, but the black stripes on upper side of the female’s wings are thicker and more pronounced.  Although this butterfly is not here in the Butterfly Center very often, take advantage of its beauty outdoors right here in Houston.  

The goldrim butterfly, Battus polydamas, is a member of the swallowtail family (Papilionidae), but it does not have the typical tails that many of these butterflies have.  The name ‘gold rim’ comes from the golden-yellow crescent shaped markings on the upper edges of both the fore and hind wing.  Caterpillars of this species are gregarious (living together) in the early stages but become solitary when older.  The caterpillars are a dark reddish gray color with paired fleshy tubercles along the back of the body.  

I am very fond of these cute caterpillars and was fortunate enough to take this adorable picture in our butterfly garden right outside of the museum.  Adults are mainly associated with disturbed areas of the forest and can be seen visiting gardens throughout the city.  They are nectar feeders and especially like Lantana.  Like many swallowtails, this butterfly flutters constantly while feeding instead of stopping to rest.  This butterfly is fairly common in Florida and South Texas and will at times stray to Kentucky and Missouri. 

Clouded Sulphur
Creative Commons License photo credit: tlindenbaum

Once spring-time hits, I seem to see this next butterfly all the time!  As a native of heavily populated areas such as parks, yards, gardens, and road edges, the cloudless sulphur, Phoebis sennae, can be seen almost anywhere along the gulf coastal states. It is characterized by its pure bright yellow to greenish-yellow wings. The males use strong rapid flight to search for a receptive female. The eggs are laid singly on leaves of Cassia,which the caterpillars happily consume, and hide underneath, to rest. The pupae are oddly shaped, compressed from side to side with a greatly distended “chest and belly”. They use a silken girdle to attach themselves to the leaf during pupation. These butterflies are harmless to plant life and are a welcome visitor to any garden.

One of the largest butterflies that I see around town is the Giant Swallowtail, Papilio cresphontesThis fantastic butterfly is native to large portions of North, Central, and South America. It very common in Houston and can be seen gracefully fluttering and sipping the sweet nectar of flowers such as Lantana, Azalea, and Honeysuckle.

Characterized by the striking diagonal yellow band across its forewing, and its long yellow-filled tails, this butterfly is a joy to see in one’s garden! The larvae feed strictly on citrus plants and are commonly called “orange dogs.” As a defense, they cleverly disguise themselves as bird droppings as they sit motionless during the day and feed at night. As with other swallowtails, these caterpillars’ posses a bright reddish orange, y-shaped gland called an osmeterium, which contains a mixture of highly noxious chemicals that smell like rancid butter. This gland helps to protect the caterpillar from small predators such as ants and spiders. The pupal stage remains inconspicuous, resembling a piece of tree bark.

These four butterflies are only a few of the wonderful butterflies that live in Houston.  If you are more interested in butterflies you should check out Butterflies of Houston & Southeast Texasby John and Gloria Tveten.  It’s a wonderful book and has amazing pictures.

Love Butterflies?
Bring them to your garden with scrumptious (to butterflies, anyway) host plants – available at our Spring Plant Sale April 4, 9 a.m. – 1 p.m. Stay tuned for more details!

The Incredible Journey of the Monarchs – on PBS

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

What do you know about monarch butterflies?

A universal favorite, most people know that these showy orange and black butterflies fly south every year to spend the winter in Mexico. Many of you may have raised their black, yellow, and white caterpillars on Mexican milkweed as a class project or in your backyard.

But why do the adult butterflies migrate, and how do they get there and back? Who are the people and cultures they encounter as they traverse the continent from north to south each year? How did we learn about their migration, and what does it tell us about the natural world?

Migration
Creative Commons License photo credit: tlindenbaum

To answer these questions, and to see some amazing footage of millions of butterflies in flight and at their overwintering grounds, be sure to watch NOVA’s long-awaited special, “The Incredible Journey of the Monarchs.” It airs on PBS tomorrow night (Tuesday, January 27) at 7 p.m.

Inspired by Sue Halpern’s book, “Four Wings and a Prayer,” the filmmaker followed the butterflies in hot air balloons and high tech gliders, interviewing researchers and ordinary citizens in Canada, the USA, and Mexico to tell the story of these unusual butterflies and the unique phenomenon of their migration.

You can catch a quick preview of the show, learn about filmmaker Nick de Pencier, or see a list of monarch links and books at the NOVA website.

According to our friends in the monarch-watching business (see www.monarchwatch.org) this film is “the best program ever done on monarch butterflies.” Don’t miss it!

Again, it airs in Houston on PBS (Channel 8) on Tuesday, January 27 at 7 p.m.

Where Have All the Bugs Gone?

It’s that time of year again. The days have gotten shorter and the temperature is slowly dropping. You may have been too busy to notice, but sometime between the shopping and cooking you probably have thought to yourself: I haven’t had to swat away any mosquitoes, or I haven’t been dive-bombed by clumsy June bugs. Where have all the bugs gone? Did they die? Are they hibernating? Well, the answer isn’t quite that simple. Over the last millions of years, insects have learned to employ all sorts of strategies to ride out the winter. While we are putting on thick socks and sweaters, the bugs are right there with us. They are everywhere, right under our noses, literally!

Visitors of the Prayerful Sort
Creative Commons License photo credit:
Clearly Ambiguous

If you’re an insect, you basically have two choices; you can stay or you can leave. An overwhelming amount of insects choose to stay put and deal with the frigid temperatures. One of the best ways to deal with the cold is to suspend your growth and remain as an egg, larva (or nymph), or a pupa. The adults of these insects do die off in the winter, but they are very busy until then. In the late summer and early spring, praying mantidsall around are laying their egg cases in preparation for the winter. They will lay hundreds of eggs, glued together, attached to a stick or leaf, and cover them with a thick layer of foam. After constructing her last egg case, the mother of many will pass away. Through the winter, the egg case will remain safe until it feels the warmth of spring. Then hundreds of tiny mantids will hatch and start the life-cycle over again.

If you are like the June bug, you will spend the winter as a fat grub, lazily feeding on roots all winter deep underground, where it is much warmer. When spring arrives, they form a pupa and emerge as adults in early summer, giving rise to the name June bug. Similarly, dragonfly and mayfly nymphs will remain under the water’s surface where temperatures stay warm enough to sustain them. This is often under a thick layer of ice! There are plenty of mosquito larvae down there to feed them through the long months. Right now in Texas, swallowtail butterflies are forming a chrysalis. The life stage that usually lasts about 2 weeks, will last for 3 months or more. Many of our visitors have a hard time thinking of a chrysalis as a living thing. It doesn’t resemble anything alive at all. When they see them wiggle in response to touch, they are always amazed. The thing that they don’t realize is that aside from not being able to see, they know exactly what’s going on. They can feel the days getting shorter, and the temperature dropping. They won’t make a move to emerge until spring comes!

If an insect is stuck as an adult, the most vulnerable life stage, it gets a little trickier! As long as they can keep their body temperature above 45 degrees Fahrenheit, they will make it. In Texas, this is not a problem, but in the north, they sometimes have to use drastic measures. These insects often find shelter in hollowed out trees, in leaf litter, and under rocks or dead logs.

If this cannot keep the freezing temperatures away they can do something pretty interesting. They can lower the water content in their bodies and replace it with a substance called glycerol. This chemical has several practical uses, but most importantly it lowers the freezing point in their bodies, acting as antifreeze! This is what can make an insect that appears frozen and dead to magically come back to life when thawed. That’s pretty impressive! This, along with going into a hibernation-like state called diapause keeps them alive. One insect that uses this method is the mourning cloak butterfly. This beautiful butterfly is the first to come out of hiding and appear in the spring.

Now if you’re a social insect, you pretty much have it made. Honeybees can store several pounds of honey for food. They don’t even need to leave the hive which is kept warm by the body heat of all the bees. Ant colonies spend all year building up a food supply and stay very deep below the ground. Even some insects that are not social will seek out others to pile on top of for warmth, like ladybugs.

bugs 2
Creative Commons License photo credit: Jef Poskanzer

Butterfly in HDR
Creative Commons License photo credit: chefranden

There are some insects that have opted to take a yearly vacation to sunny Mexico, which would definitely be my choice! The monarch, perhaps the most well known insect in North America makes this amazing journey every year. It’s a mind boggling to think that millions of butterflies fly up to 3000 miles to a few sites that they have never been to or seen before, how do they know how to get there? It is a mystery that keeps us all enchanted by the amazing insect. If you’d like to learn more about the monarch butterfly and their journey, visit the monarch watch website.

Since we live in an area with very mild winters, there are some bugs that we still see all year, including a lot of butterflies. There are a few local monarchs that don’t feel the need to migrate south. Every year we get several calls from people who have spotted a monarch and want to know what will happen to it or if they should help it. The answer we give them is to just let it be, the temperature will probably not drop low enough to kill it and if it does freeze, the butterfly will find shelter. They know how to deal with the cold! So you may enjoy this little break from the bugs buzzing all around us. As for myself, I can’t wait until the spring when all of the bugs are back, happily doing their jobs to keep the world turning! Plus I hate cold weather!

Go buggy! Learn more about insects:
The Sphinx Moth: It’s a Work of Art
Don’t worry, it doesn’t hurt: learn how to pin a butterfly
Do butterflies breed? Your butterfly questions answered