HMNS entomologist Erin Mills walks you through how to mount and display a butterfly in this 4-part video tutorial.
Part I: Supplies
Check back next week for Part II!
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
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!
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.
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.
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.
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.
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.
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.
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.
Editor’s Note: The term “BioBlitz” was first coined in 1996 for intense attempts to record all the flora and fauna within a designated area. National Geographic, which has partnered with parks around the country for various BioBlitzes, describes them as “a 24-hour event in which teams of volunteer scientists, families, students, teachers, and other community members work together to find and identify as many species of plants, animals, microbes, fungi, and other organisms as possible within a designated area.” These quick and dirty surveys are used both to gather information about the biodiversity of a given area, and since members of the public and other non-experts (students, etc.) are often included as participants, as ways of sparking public interest in local flora and fauna.
The “Eco-Tech” panel of the Memorial Park Conservancy recently recruited the Butterfly Center to conduct a preliminary survey or “mini-BioBlitz” of the insect fauna throughout Memorial Park, with the idea of inviting members of the public to help on future surveys. One of the goals of the panel is to get some baseline data on the biodiversity of all the creatures that live in Memorial Park, and from there, make plans on how best to preserve and manage or enhance this wildlife.
We were asked to survey several different natural habitats in Memorial Park (i.e., not the golf course). On a sunny morning in early July, Butterfly Center staff members, our summer intern, and a couple of volunteers drove out to Memorial Park armed with insect nets and containers. While some surveys (such as birds or trees) can be done without collecting, there are so many kinds of insects (and so few experts) that at least some specimens have to be collected in order to make identifications.
We decided to sample 10 transects — 100 feet long by about 8 feet wide — each one in a different area. Our first couple of sites were in open prairie vegetation, so we used sweep nets and aerial nets to collect samples. In case you are not versed in insect collection techniques, a “sweep net” is a canvas net bag on a sturdy metal frame that is swished through the vegetation. Periodically, the contents are emptied into Ziploc bags or other containers.
Aerial nets are the more familiar “butterfly nets”: a much lighter, more delicate net bag that is swung through the air (it should NOT be dragged on the ground, used in water, or swiped through bushes!). These nets are more for catching fairly large, individual insects, especially ones that fly, so samples are put directly into a glassine envelope, or vial, or other appropriate container (or, if it is something readily identifiable, simply noted and released). Sweep nets generally collect things like grasshoppers and katydids, walkingsticks, mantids, leaf hoppers, stink bugs, the odd caterpillar, spiders, etc. Aerial nets are useful for larger flying insects such as butterflies, dragonflies and damselflies, wasps, bees, some beetles, certain flies, etc.
In the more forested areas, sweep nets were not really appropriate, so we used the aerial nets and also took litter samples (scraping up leaf litter and bagging it). Litter samples are typically brought back to the lab to process in a so-called Berlese funnel. Many small arthropods who live in the litter of the forest floor, including springtails and cockroaches, ants, small beetles, millipedes, etc., can be collected in this way.
There are many other collection techniques, none of which we used in this preliminary survey. Pitfall traps are always fun; they are empty cans or jars set into the ground with their mouths at ground level. Sometimes bait (a little raw chicken or fish, for example) is put in the bottom.
Crawling insects, especially those interested in odorous food, fall into the “pits” and cannot get out. Such traps need to be checked every couple of days — often they will contain different kinds of beetle, maybe a cockroach or two, etc.
Malaise traps are screen tents or baffles that trap small flying insects. The insects get caught in the folds of the screen and since they typically crawl upwards to escape, can be funneled into a container filled with alcohol.
Yellow pans are any wide, shallow container with a yellow (painted or otherwise) bottom. These are partly filled with water and a bit of liquid detergent. Wasps and pollinating flies, etc., are attracted to the yellow color and cannot escape once they fall into the soapy water. Yellow pans need to be used in open areas in sunny weather and the samples removed every day or two.
Our final survey site was along the banks of Buffalo Bayou, which was much higher than usual so there was not much shore. Here, we mostly used aerial nets. We saw several things in this area that were not seen other places, especially tiger beetles, damselflies, etc. Here, we mostly used aerial nets (or grabbed things with our hands).
By noon, it was blazing hot and we were all soaked in sweat, so we bagged things up and stopped at the Shandy Café (great little place on Memorial Drive) for lunch on our way back to the Museum.
Although we only collected for about three hours, we have our hands full in identifying everything. We first have to sort things to order, identify what we can, and then we will probably have to send some things off to experts in the various insect groups. I’m sure it will take us several weeks!
Some of the coolest things we found:
It’s always fun to open up the sweep net and find walkingsticks or praying mantids, or a colorful leafhopper. We picked up quite a few different grasshoppers and a few katydids. We noted but did not catch too many butterflies (we can identify most of these by sight, so no need to collect).
I like wasps and bees; we saw several of the large red Polistes wasps, carpenter bees, leaf cutter bees, and a really cool “digger” bee starting her nest tunnel in the sand (see attached video clip). A medium-sized beetle that looked like a wasp was visiting flowers in several places.
The very fast tiger beetles mostly eluded us down at the bayou’s edge, but we did catch a few damselflies there. The most common one there was the lovely Ebony Jewelwing.
Once we have compiled our results and reported them to the EcoTech Panel, they will then make plans for another survey sometime in the fall. I believe they intend to invite more general participation, so if you are interested in the insects of our area, keep your ears open!