It Takes a Village ….A Milkweed Village

monarch-2

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!

Horticulturalist Zac Stayton bids a fond farewell to HMNS

Editor’s Note: After four and a half years, Zac Stayton, Horticulturist for the Cockrell Butterfly Center, is leaving HMNS for a new job as a Project Manager for the grower Color Spot. I sat down with him this week to discuss his time at HMNS, his favorite projects and what he’ll be up to next.

Zac Blog 1

Vincent Covatto: So Zac, we’re very excited for you about your new prospects, but sad that you’ll be leaving. Could you tell us a little about what your job has entailed here at HMNS?

Zac Stayton: Basically, the beautification and upkeep of the Butterfly Center itself, from making sure all the plants are blooming, which ends up feeding the butterflies, to maintaining the tropical fruits, pollinating the chocolate trees and the coffee. Pretty much everything that goes into the conservatory itself, from irrigation and upkeep of the waterfall to electrical and everything in between.

VC: So we’ve essentially been running you ragged for the last five years.

ZS: [laughing] You could almost make it a job for a team of four.

VC: Or one Zac.

ZS: [laughing] Yeah, yeah.

VC: What are some of your favorite things that you’ve worked on in your time here?

ZS: Of course Lois and some of the tropical flowers that you wouldn’t normally get to encounter here in the Houston climate. There are some crazy orchids that we’ve got in there. We’ve got one in particular that’s endangered, and almost went extinct when the Japanese invaded a small island off the coast of Taiwan, so it’s very, very rare. Just getting to see some those plants bloom, I mean I’m one of the few people that ever gets to grow these plants, is really a great experience.

Also being able to grow coffee and chocolate, pineapples and vanilla — which you wouldn’t get to do outside of the glassed-in enclosure there in the conservatory.

VC: I remember this past winter we had had a coffee tasting in the conservatory. Was that sort of your own pet project?

ZS: Yeah, that coffee tree was actually kind of a fluke, we call it a volunteer. We took an old [tree] out when I first started and it dropped one single seed and it ended up growing into this tree that we didn’t even mean to plant there. And so, I guess it was maybe last September, October, I looked at it and it was just covered in berries, and it was like, well we’d better do something with all this coffee, rather than just letting it all go to waste.

So I went through and kind of studied how to do it and there’s not a lot of — like a lot of things in the Butterfly Center… you can’t just google these plants and see what to do. So I had to do a lot of calling around.

Here in Houston there’s plenty of coffee shops that will roast the beans for you, but we had undried beans. And it was like, ok how do we get these to the point where we can roast them. So we really had to break it down step by step and do some trial and error, with the whole process — from cracking the beans and drying them and roasting them and then finally grinding them and finally drinking them. It was pretty eye opening to see what actually goes into your daily cup of coffee.

VC: [laughing] Or four…

ZS: [laughing] Yeah depending on the day. Two for me at least. Minimum.

VC: Well I bet that was your favorite cup — the best coffee you’d ever had.

ZS: Definitely. Definitely, yeah, I mean I think everybody in the Butterfly Center got blisters on their fingers just having to — there’s what’s called parchment coffee and you basically have to take this thin layer of parchment off of each of the several thousand beans that we had. And they have machines for that for that kind of stuff in the tropics, but I couldn’t find one, at least in the area. I think the closest one was in Hawaii or Coast Rica, so we had to do it all by hand. And so you definitely get a new appreciation for coffee.

VC: Do you have a favorite plant, either inside the conservatory itself or something you’re really interested in?

ZS: I have a favorite plant family. I like bromeliads. So everything related to — the closest relative would be pineapples, but they also include Spanish moss [so there’s a big range]. I actually grew these in Hawaii before I came here so that’s kind of been my expertise, if you will, I’ve channeled myself into those a little bit more than some of the other plant species.

VC: So what is your new job?

ZS: [I’ll be working for] Color Spot the largest grower in the U.S. right now, and they have several locations — I thinking six or seven in Texas — but the branch that I’ll be at is in Huntsville. And I’ll be the production manager, making sure the timing goes through. Most the plants there are bedding plants, they’re seasonal.

For example, when Christmas time rolls around it’s going to be my job to make sure that all the poinsettias and mums and things like that are all ready, that they’re nice and red and at a specific time are on the shelves ready for people to buy.

VC: So you’ll be making sure that everything is timed right.

ZS: Exactly.

VC: So you determine when things are planted, when they’re harvested?

ZS: Exactly. There are a couple teams of growers, so I’ll be the Production Manager, from the time the plant gets put in the soil, until the time it gets on a truck headed to the main customers — I make sure it’s all on schedule.

If you’ve ever bought a plant from Walmart or Home Depot, or Lowes or Kroger, any of those big box stores, especially here in Texas, it’s come from Color Spot. Also smaller nurseries around town will buy their plants.

VC: So would you say this job is a continuation of the sort of work you’ve done for the museum or is it more of a fresh start?

ZS: It’s kind of a fresh start. It’s changing gears from tropicals to basically what grows well around here. A big part of it though will be — working here I learned a lot of the butterfly attractants for our area, although I work with tropicals on a daily basis there are a lot of calls asking “well what can I plant in my backyard?” So learned a lot about our native butterflies here and what plants attract them, and what plants you can put in your garden. And that’s a big part of what I’m going to be growing at Color Spot — butterfly attractants, nectar plants — so there is an overlap there.

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VC:  And you have the different pollinators to take into account with that as well?

ZS: Yes, exactly. Everything about pollination and pollinators I learned here firsthand. When I first started I didn’t know much about butterflies — I knew the monarch, the one that everybody knows, and other than that I didn’t know that there were 15 other species of butterflies that are native here, to Houston. That is something I’ve definitely gained from my time here.

VC: Is there anything that you’re really excited about growing or working on at Color Spot?

ZS: There are a lot of new bulbs, tulips and things like that, that we get to do trials with. Before they even hit the market we get to take some of these bulbs that these growers bring from the Netherlands and get to try them out, test them out, in our greenhouses. We get to be on the front line before anyone else [in the area] knows about them — that’s something I’m really excited about.

VC: I’ve been reading through some archival press from when Lois was blooming, and I saw a couple of places where you’d been quoted. I think that’s how some of our Houston audience got to know you — through that experience. Can we count on you to come back down the next time she’s in bloom?

ZS: Oh yeah definitely. I’ll be here of course, I wouldn’t miss it.

VC: Do you think you’ll become pen pals with her?

ZS: [laughing] Oh no, I don’t think so. No more anthropomorphizing Lois, although that was funny and clever when that happened.

The people though, that’s what made Lois what she was. Lois was just a flower, and people would probably gasp hearing me say that, but it was the whole community rallying around Lois that was the coolest part of the whole thing.

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80,000 plus people coming out, plus the people —you know, we had people in Australia saying “get out of the way! We can’t see Lois on the webcam!” So just the fact that it was everybody at the same time, seeing the same thing and it just blew up on social media. And that’s what I though was so cool, everybody so in synch, waiting, just to see what would happen with Lois.

As a horticulturist it was really cool to see just everyone getting around it and thinking it was as cool as I did. Normally, you know I’ll be like “ooo look at this cool plant!” and people couldn’t care less, but to see everyone else sharing that passion — that was the best part about it.

Zac Blog 4

 

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VC: Is there anything else you’d like to say or share with our readers on the blog?

ZS: It’s been a fantastic four and a half years here, and honestly all of the events that we did, it wouldn’t have been possible without people getting as geeky about plants as me.

From the miracle fruit tasting, and the chocolate and the coffee — to see everybody getting around it, that was the best.

Lois, kind of spurred everybody on to find this new kind of passion in horticulture. There were a lot of parents that came up to me and said “I asked my kid what they want to do and now they all want to be a horticulturist.” And that’s the best thing that could come from it, I think, is a whole new generation of people that find plants as interesting as I do.

 

Hug-A-Bug, This Saturday!

Spring is almost here (thank goodness!) and soon Houstonians will be working in their gardens like busy little bees. You can fill your garden with some wonderful plants from our annual spring plant sale, which will be held on April 10th. Before then, however, you can take the opportunity on Valentine’s Day weekend to learn about the world of beneficial insects at Hug-a-Bug! Put those pesticides down because your garden will love you, if you love bugs!

Stop And Smell The Flowers
Creative Commons License photo credit: I Shutter

Pests can be a pain in your garden, but Mother Nature has a plan. This is where beneficial insects, such as ladybugs, come into play. Pesticides can harm creatures of all walks of life, not only targeting the pests, but beneficials such as butterflies and bees, not to mention defenseless animals such as frogs, toads, and lizards. They can also leave residue on your plants. Biological control is the most eco-friendly and effective method. Here are a few beneficial insects you’ll meet at Hug-a-Bug, and you can even purchase for your own garden.

LadybugsAhh ladybugs - beautiful, peaceful, and fierce predators! Most people are under the impression that these cuties of the bug world feed on nectar, but they are actually hungry for blood – aphid blood! Ladybug larvae and adults feed on plants pests, especially aphids. If aphids are in short supply, they will go after other soft-bodied pests such as whiteflies. At Hug-a-Bug, we will be giving away vials of ladybugs for you to release in the butterfly center or even in your garden at home!

Green Lacewing - Chrysoperla carnea
Creative Commons License photo credit: yaybiscuits123
Green Lacewing

Green Lacewings - Not familiar with these guys? Well, pay attention to your front porch light at night and you might notice these dainty little bugs flying around. The adults have a green body with large, lacy looking wings - hence the name! The adults are harmless pollen and nectar feeders while the larvae, like ladybugs, munch on soft-bodied plant pests.

Parasitic Wasps - When most people hear the word wasp they think of red wasps, yellow jackets, and hornets. These are of course not favorable to people because of their nasty stings. But the vast majority of wasps go completely unnoticed by people. They are tiny and parasitic on other arthropods. Each species has a specific host, whether it is a type of caterpillar, aphid, mealy bug, scale, or whitefly. These tiny wasps have no stinger and buzz about protecting our plants from pests.

Afican Praying Mantis
Creative Commons License photo credit: SMB(spidermanbryce)

Praying Mantis - You know this is one of my favorite bugs! Highly intelligent, expressive and thoughtful, they are just fascinating! Most people know the praying mantis because of its distinct appearance. They may not be quite as beneficial as some of the more specialized predators, but they are a friend to your garden none-the-less. If you don’t like larger bugs such as caterpillars or grasshoppers munching on your foliage, these are for you!

Mother Nature is truly incredible! For every plant’s pest, there is a predator or parasite out there to keep them in check. If you let nature run its course in your yard, you will have a very healthy little ecosystem to observe and admire.

If you need any help, all of these bugs can be purchased in large quantities from many places including Rincon Vitova, a pioneer in biological control.

I hope you will come join us at  Hug-a-Bug this Saturday, February 13 in the Cockrell Butterfly Center from 11 to 2 to learn more about these fascinating beneficial insects and see them up close and personal. There will also be fun crafts and games for the kids and a chance to talk to the butterfly center’s very own staff of entomologists and horticulturalists. We hope to see you there!

My Summer at the Cockrell Butterfly Center

Laura Adian, an intern in our Cockrell Butterfly Center, is a guest blogger for us today.  Join us as she writes about her summer internship and what tasks she does for the museum, maintaining the butterfly center and the greenhouses.

Howdy!  My name is Laura Adian and I am one of the horticultural summer interns at the Cockrell Butterfly Center.  I am a senior Horticulture major, minoring in Business, at Texas A&M University. Although I am interested in all areas of horticultute, my specialization is fruit and vegetable production.  I wanted to give you a quick insight into my daily job here, as well as the day to day happenings in our butterfly center, so here it goes.

On Mondays and Tuesdays, I work in the main conservatory.  One of the most important things I do on these days is what we call “open” the Butterfly Center.  This involves sweeping the leaf debris from all of the pathways and stairs, watering and raking the plant beds, putting out the amino solution and rotten fruit for the butterflies, feeding the iguana, and turning on the waterfall.  Basically we just want to make the place look great for the public. 

After opening, there is always deadheading (pulling the dying blossoms off of a flower) and pruning to be done.  This has to be done every week to encourage more flowering and to keep the plants looking their best.  Fertilizing some of the flowering plants and orchids is another task that must be done on a regular basis in order to ensure maximum healthy growth. 

Passion Flower
Creative Commons License photo credit: Just chaos

For the rest of the week, I work in the greenhouses and in the Demonstration garden.  Up in the greenhouses, we raise butterflies and plants. 

Greenhouse #1 is where we do most of the propagating and repotting of the plants.  Greenhouse #2 is filled with 800 plants, mostly Passiflora, that we use as host plants for the butterflies.  This is also where we do recovery of the plants, after the caterpillars munch all the leaves off them. 

Greenhouse #3 contains the insectaries and pupation cages full of butterflies and caterpillars.  Every week, the host plants in the insectaries that are full of eggs are transferred to the pupation area.  Then, we put fresh host plants and nectar sources (from Greenhouse #2) into the insectaries.  In the pupation area, the hungry caterpillars must always be fed, which means transferring them from the already eaten, leafless plants to fresh plants that we bring from Greenhouse #2.  Afterwards, we take the eaten plants to the recovery table in Greenhouse #2.  This is the never-ending cycle of raising all the beautiful butterflies. 

One of the bigger projects we had to do this summer was to re-tie and re-moss all of the orchids in the conservatory.  The orchids are scattered throughout the conservatory on trees and poles and they must be rewrapped every year in order to keep their roots from drying out and to keep them looking nice.  That was quite a task because there are dozens of orchids and every time you think you’re done, another one seems to pop up.

Tattered Butterfly
Creative Commons License photo credit: B~

In the next week or so, we will be putting half a semi-truck load of soil into all of the beds in the conservatory.  We will also be planting 100 red and pink Pentas to ensure fresh nectar sources for the butterflies.  This is obviously a big undertaking but it must be done every summer and I can’t wait to see how good the conservatory looks after we’re done.

We also have to water in the greenhouses every day and fertilize all the plants regularly.  Then, of course, there is the general maintenance of the greenhouses, which seems to be an ongoing project.

Me in the demonstration garden

In the Demonstration garden, we are planting many new nectar sources and host plants for the butterflies to come check out.  Since I’ve been here we’ve planted Pentas, Pink Turk’s Cap, Asters, Milkweed, Lantana, Celosia, Passion vines, Dutchmans’ Pipevine, and many more.  Right now, we are in the process of planting Dwarf Mondo grass in between the cracks of all the stones.  We have already planted 7 flats and will plant 10 more in the weeks to come.  In the next few weeks, we will also add a bench and some other focal areas.  Again, watering and fertilizing must be done on a regular basis.  The Demonstration garden is one of my favorite projects and it looks fantastic.

We also maintain the plant cart in the Grand Hall of the museum.  We price plants from the greenhouse and bring them down to the plant cart to sell.  We sell nectar sources and host plants such as Salvia, Pentas, Lantana, Passion vines, and Durantas.  We have to sweep the plant cart, water the plants, switch out plants, and fill the brochure holder on a daily basis.  For the Fourth of July weekend we even did a red, white, and blue theme.

I have even been fortunate enough to get to go on fieldtrips to some great nurseries this summer.  We have been to Treesearch Farms, Hines Nursery, Nelson Water Gardens, and Cornelius Nurseries.  We are also planning on going to Mercer Arboretum later this summer.  None of this would be possible if not for the great staff at the Butterfly Center and their desire for us to have an awesome experience this summer and to see all that we can in our 10 week stay.

That is basically my summer in a nutshell.  I really couldn’t have asked for a better internship or better people to work with this summer.  I have learned so much about butterfly rearing and all that it takes to run a huge operation like the Cockrell Butterfly Center.  More importantly, I have met some amazing people who are top in their fields, always willing to lend a hand, and really passionate about their work.  My experience this summer would not be nearly the same without them.