July 21, 2022
I first notice the scent from 40 yards away, subtle but powerful. The milkweed is fragrant, almost like carnations. I’m at the edge of the largest patch of showy milkweed (Asclepias speciosa) that I know of around Helena. The robust stems grow up tall out of the smooth brome along the canal. On the other side, traffic rushes past along York Road. I’m at West Mont Farm and Gardens, where I’ve gotten permission to look for insects on the milkweed this morning. And there’s one insect I’m especially hoping to find: the monarch butterfly.
The migration of monarchs is a story so well-known that it falls easily into clichés.
The epic migration of a half-gram insect. For years, the story of the monarchs was just an abstract concept to me. Did we even have monarchs in Montana? From time to time, I would ask a biologist. They were rare here, it seemed. Maybe they were just migrants. Did they ever breed here? Maybe in eastern Montana. Maybe once in a great while.
Not quite so rare
Then I met Laura Alvey, who lives at the edge of the Helena Valley, where the land rises up into the granitic mass of the Scratchgravel Hills. Her yard is an oasis of native plants that she has planted and tended over the years. Showy milkweed (Asclepias speciosa) grows exuberantly there. And I was thrilled to learn that Laura has not only seen monarchs here – they have also laid eggs on her milkweed! She has gotten closely familiar with these butterflies. With her children, she’s raised several of the caterpillars to adulthood, providing them a safe home through the larval stage and then releasing the adults to continue their journeys.
The conversation with Laura was my first clue that monarchs are an important part of the Montana landscape. And then last winter, I learned about the monarch studies Maggie Hirschauer and a team of volunteers were doing in western Montana’s Bitterroot Valley, from Missoula to Stevensville. From 2019 to 2021, they found 41 wild monarch eggs and larvae in that valley. So do monarchs breed in Montana? Yes! And not just one or two of them. It was at this point that I knew I wanted to take a closer look around Helena. If they could survive in Laura Alvey’s yard, surely there might be other patches, too?
The danger of extinction
But today, a shadow hangs over this long-awaited monarch search. As I scanned my news feed before I came out here this morning, I read that our monarchs (Danaus plexippus plexippus) had just been listed as Endangered by the IUCN. This is a non-regulatory ranking put out by an international, highly respected group of scientists. An IUCN Endangered listing is a major cause for alarm, but it’s not regulatory: unlike the Endangered Species Act, it doesn’t impose legal obligations.
In the case of our native monarchs, there is major cause for alarm. In the past three decades, monarch populations overwintering in California have shrunk by over 99 percent. From nearly 10 million in the 1980s, they’ve crashed so hard that now there are less than two thousand of them left. More monarchs still overwinter in Mexico, but the Mexican population has declined by 84 percent since the 1990s. In short, our migrating monarchs are at risk of extinction.
This is grim news, but it makes today’s search even more timely. Are there still monarchs in the Helena Valley? If they’re anywhere in this valley, it seems like they might be here, in West Mont’s extensive milkweed patch. The milkweed extends for over a hundred yards, a forest of velvety green leaves and pink flower umbels. Between York Road and the farm itself, it’s a luxurious milkweed thicket, growing alongside the irrigation canal and two smaller ditches. I have no idea if I’ll actually find monarchs today. But monarchs or not, I’m hoping I’ll learn something about milkweed and the creatures it sustains.
The trapped honeybee
Right now I’m sitting at the edge of the patch, taking a close look at the milkweed flowers. Hundreds of honeybees are flying from one flower to the next. I can barely hear their buzzing over the steady rush of the irrigation pump nearby.
I spot a honeybee struggling wildly on a milkweed flower. Its hind leg is caught. The bee is fluttering desperately to get free. This is something I’ve read about in Milkweed, Monarchs, and More, a delightful field guide that has helped introduce me to the milkweed community. It turns out that this stuck honeybee can teach us a lot about milkweed flowers and how they get pollinated.
How milkweed gets pollinated
The flowers are striking: works of evolutionary architecture as intricate and weird as those of leafy spurge. At peak bloom, the milkweed petals are a striking carnation-pink, each with crisp white edging. The petals bend backwards, accentuating five intricate white horns that protrude from the center. Each horn has a cup at its base, and each cup holds nectar. Meanwhile, between the horns there’s something that looks like a greenish-white barrel.
This barrel holds the pollen and the incipient milkweed fruit – but it’s also a trap. Along its edges are five vertical slits. Each slit holds pollen, neatly wrapped up into tidy, elongate packets. From time to time, as a bee or a fly gathers nectar, its leg will fall into one of these slits. And as the insect struggles to free its leg, it picks up a pollen packet.
This honeybee has a leg stuck in the pollen barrel. As she tries to get away, I can see the yellow pollen packet dangling from her foot. She keeps buzzing her wings, but her leg remains stuck. Finally, after a minute or so, just as I’m about to help her, she struggles free and flies off, carrying the pollen towards the next flower cluster.
But this bee seems to be the exception rather than the rule. I watch dozens of others deftly sticking their heads into the milkweed horns, gathering nectar, and moving to the next horn. Apparently, the nectar is good enough that it outweighs the small risk of getting stuck.
Ants and milkweed bugs
Besides the honeybees, there are lots of ants here, each one black with a reddish thorax. Like the honeybees, they’re busy crawling into the milkweed horns, gathering nectar.
According to Milkweed, Monarchs, and More, ants take nectar from milkweed without contributing to pollination. But apparently Montana’s ants don’t know that. I watch one vaulting from horn to horn, a yellow pollen packet trailing awkwardly from its middle leg.
Nearby, I catch sight of a small milkweed bug (Lygaeus kalmii). It’s as striking as the milkweed flowers themselves, a portrait in red, gray, and black. These bugs are less commonly-known than monarchs, but they are also a characteristic part of the milkweed community. And they’re important to the interactions that go on here: not only do they feed on milkweed foliage and seeds, but they also scavenge dead insects. Sometimes they even attack monarch larvae. Earlier in the spring, they may also feed on other plants nearby.
I still haven’t moved from the spot where I’m sitting, by the pump. From this vantage point, the milkweed patch really does look like a forest. The thick stems and broad leaves arch skywards, carrying the pink flower clusters.
Beginning the search
The West Mont Farm manager, Jeremiah, tells me that he’s already seen a few monarchs this year, elsewhere in the Helena Valley. Have they visited this patch, too? Monarch females can lay up to 400 eggs. Typically, they lay each one singly, hidden on the underside of a milkweed leaf. There are thousands and thousands of leaves here. It’s time to start looking!
Now I begin to search the velvety leaves for monarchs. I check the undersides for eggs, look for larvae, and watch for signs of feeding. It’s a daunting, massive task. I keep getting distracted as my eyes gravitate to the honeybees on the flowers. Ten leaves in, I spot a daddy long-legs (order Opiliones), one of those familiar spider-relatives that scavenge and hunt small insects. After a dozen more leaves, I find a tiny spider nestled in an inconspicuous web. It’s hidden in a fold near a leaf tip.
My eyes wander back to the milkweed flowers. We have blooms of all stages here, from unopened buds to pink and white umbels at the peak of flowering. The horns grow creamy as the flowers fade. There are already a few fruits developing, still no larger than an almond.
Okay, back to leaf-searching. There’s a greenish grasshopper nymph resting low on the milkweed, missing a hind leg. Near it, half of a leaf has been chewed away. Nearby, I spot another grasshopper. This is an adult two-striped grasshopper (Melanoplus bivittatus). Strangely, this one is also missing a hind leg, plus part of an antenna. Did both grasshoppers manage narrow escapes from a spider, or from some other predator?
Other butterflies and their eggs
I notice a small white blob under a milkweed leaf. Is it a monarch egg? No, it lacks the fine sculpturing. And there’s a faint white trail where it rolled down the leaf: it’s a blob of dry milkweed sap.
Then I spot a flash of movement: there’s a butterfly on the milkweed flowers! It’s a big one, but it’s not a monarch. Instead, it’s a western tiger swallowtail (Papilio rutulus), and it’s very interested in these flowers. Normally I see tiger swallowtails in flight, ignoring flowers and floating powerfully past on strong wingbeats. But this one is avidly nectaring, unfurling its proboscis at flower after flower and probing the milkweed horns for sugars.
Why am I so easily distracted from my leaf search? If only I could find an adult monarch here, this whole process would be so much easier! This spring, on May 4, that was exactly the experience I had with a Milbert’s tortoiseshell butterfly (Aglais milberti). I noticed an adult along a stream, resting upside down on a stinging nettle leaf (Urtica dioica). Knowing that stinging nettle is the larval host plant for this species, I watched carefully. The butterfly rested for a long time on the leaf, then flew away as I inched closer. And there, well-hidden on the underside of the leaf, I found a cluster of 11 barrel-shaped eggs. If only the monarchs would be so obliging…
Monarchs and viceroys
And then, right after I have that thought, I see a monarch. At least, I think it’s a monarch. I still need to see it land and get a better look. Besides monarchs, we also have viceroys (Limenitis archippus) around here – and these butterflies do a great job of mimicking monarchs. But although these species look so similar, their life cycles are incredibly different. Our monarch larvae depend on milkweeds (Asclepias spp.) and are obligate migrants. The only way these butterflies reach Montana is by a long migration from overwintering sites in Mexico or California. Viceroys, on the other hand, do not migrate. Their larvae feed on willows (Salix spp.). And somehow, these larvae survive the Montana winter hanging from a willow, wrapped in a dead leaf.
The large orange butterfly is circling warily. I stop breathing. It lands on a flower for the briefest of instants, then reconsiders. Leaping back into the air, it circles around me. I try not to make any movement. It flutters rapidly eastbound. I follow at a discreet distance. Now it’s landed again, and this time it’s probing the milkweed horns with its proboscis.
I raise my binoculars, then the camera. Yes! The hindwing is a clean, black-veined orange, without the interrupting black bar that identifies a viceroy. It’s a monarch in the milkweeds! This is pretty special.
Two special butterflies
For that matter, viceroys are pretty special, too. From what I’ve seen so far, both species seem to be fairly rare around Helena. Last week, on July 16, I was leading a bird walk at the Upper Prickly Pear Fishing Access Site. As I casually checked a patch of flowering milkweed there for monarch larvae, I saw a large orange butterfly in flight. A monarch? This one was not. When it landed, I was able to see the interrupting black bar cutting through the hindwing. It was a viceroy. And in nearly six years of living in Helena, this is only the second viceroy I’ve ever seen. But are these butterflies actually rare here, or do I just need to look harder? I’d love to hear about your observations in this area: either viceroys or monarchs! If you’ve seen them, please leave a comment!
Distracted by beetles
The monarch is flighty, spending only a short time on one flower cluster before moving on to the next. And it’s only nectaring – I don’t see any sign of egg-laying behavior this morning. And no wonder: when it spreads its wings, I see a small black spot in the middle of the hindwing. Only male monarchs have this spot. This one won’t be laying eggs.
Still, a monarch is here! And if one is visiting, hopefully others are too. It’s time to redouble the egg search.
But first, I find another excellent distraction. There’s a pair of striking red beetles mating on a milkweed flower. These are milkweed longhorn beetles (Tetraopes sp.). And like monarchs and the small milkweed bug, Tetraopes are characteristic milkweed associates. The larvae feed underground on milkweed roots, while the adults chew on the foliage. After mating, they’ll lay their eggs at the base of a milkweed stem, completing their life cycle.
Several other Tetraopes are crawling on milkweed leaves nearby. I notice that several of these leaves have the tips cleanly cut off in a half-circle: a classic feeding sign left by these beetles.
Searching through the milkweed
I’m completely daunted by the prospects of finding a monarch egg, or a tiny larva, among all of these leaves. But if I don’t look, I definitely won’t find anything. I decide that I’ll give myself an hour to do a careful search. I’ll check leaf undersides, look for leaves with feeding damage, and keep my eyes open for adult monarchs. And for this hour, I’ll try not to get so distracted.
It’s not quite noon yet, but the day is already hot. A blustery west breeze has picked up. I decide to focus on the area where the milkweed is especially extensive. The male monarch was nectaring here – so maybe females favor similar areas. Ready, go!
There’s something rather calming about pushing back the soft milkweed leaves, looking for butterfly eggs. If it weren’t for the occasional mosquito whining in my ear, this would be very relaxing. Although the mosquitoes aren’t the only problem. Among this forest of milkweed, I haven’t found a single monarch egg. They must be here, I keep telling myself. I start to suspect that there’s something wrong with my searching technique. Maybe I’m overlooking them. May I’ve already skimmed past dozens of monarch eggs!
Now I’m 24 minutes in, and I’m beginning to feel pretty silly. I’ve checked hundreds of milkweed leaves. No eggs. Nothing.
Hiding in plain sight
Then I look up, and my heart stops. There’s a lone milkweed plant at the edge of the patch, and among its flower buds is a caterpillar. It’s clearly a monarch, strikingly obvious among the buds, boldly banded in white, black, and yellow. It’s almost two inches long, far past the stage at which young monarch larvae try to hide. Its message to predators is clear: I taste bad! Don’t eat me!
The caterpillar rests, quiescent. Below it, a quarter of a young milkweed leaf is gone. Presumably this is where the caterpillar started its life. At least one of them is here! And where there’s one, there might be hundreds more.
I continue the search, alternating between a quick, general look for older caterpillars and careful leaf observation in search of eggs. From time to time, I see leaves with signs of feeding, but I have no idea if these signs are from monarchs or from some other creature. Each time, I check the surroundings for caterpillars, but I find none.
The pollinators of milkweed
I haven’t seen any more adult monarchs since I spotted the nectar-seeking male, hours ago. As I walk in search of monarchs, I’m still noticing the flower visitors. There are hundreds upon hundreds of honeybees. They and the ants are by far the most abundant insects on these flowers. I find one dead honeybee, its leg still trapped in a pollen barrel, another leg clinging to a packet of pollen. This one wasn’t able to get free. Besides the honeybees, I spot a yellow-haired bee fly and a few other flies. A single bumble bee (Bombus sp.) is visiting the blooms. But the diversity of flower visitors today is surprisingly low, much lower than what I saw on leafy spurge last month.
Why, I wonder? Why is it that ants and a non-native bee are the only common pollinators on this nectar-rich native plant? In the past, I’ve casually noticed several wasp species visiting milkweed flowers. But I’m not seeing them today, nor am I seeing other types of bees. I wonder if this might be a reflection of the broader landscape. This part of the valley is a mix of housing developments and agriculture. Native plants seem few and far between. Could it be that other pollinators are missing important resources that they need? What if we provided a greater diversity of flowering plants? If we left areas of bare soil for ground-nesting species and dead twigs for stem-nesting bees, would we find more pollinators on the milkweed? Or is milkweed just not very attractive to many of our flower-feeding insects?
Leaving with questions
I check a few more milkweed plants, searching the leaf undersides. I notice a few ladybugs, a couple of seven-spots and a couple of transverse ladybugs. These are the species I found so commonly on the sagebrush last week.
The sun is overhead now. My hour is up. After seeing the single caterpillar, I haven’t found any more monarchs.
Are there more of them here? Among the complexity of this milkweed forest, it’s easy to imagine them hiding, eggs or tiny larvae within this sea of leaves. Perhaps I can come back in a few weeks and look again. Or maybe that’s all this year: one monarch from Helena’s milkweed stands. With luck, it will avoid the small milkweed bugs. I hope it will pupate successfully and flutter skywards next month, bound for a destination that only it knows.
It’s not clear where Montana’s monarchs go. In her work in the Bitterroot Valley, Maggie Hirschauer has observed wild, captive-reared adults orienting mostly to the east and southeast when they are released. This suggests that they aren’t bound for California. And in a 2005 article, Hugh Dingle and other researchers suggested that monarchs in our area likely migrate southwards to Mexico, finding their way along river corridors.
From our milkweed to Michoacán
After spending a morning here, this milkweed patch has found a special place in my heart. Where else but in a patch like this can we find milkweed longhorn beetles and small milkweed bugs? Where else can we watch honeybees, ants, and swallowtails sipping nectar from incredible blooms that smell like carnations, sometimes getting stuck in the pollen barrel?
In a moving video, Will Smith tells of how the monarchs arrive in Michoacán, Mexico every year, just in time for the Día de los Muertos (Day of the Dead). People see them as the souls of the dead, returning in celebration of family and connection. It’s not clear yet whether our Montana monarchs are among those returning to Michoacán. And if they are, it’s still harder to imagine their journey. But I like to try.
This November, imagine this caterpillar in its winged reincarnation, gliding over the streets of Michoacán and feeding on nectar from the golden cempasúchiles that decorate the graves of the dead.
To return from the dead
For a monarch to arrive in Michoacán, so many things must go well. There must be healthy milkweed populations all the way from Canada to Mexico. The caterpillars must avoid predators and drought. The adults must fly thousands of miles, avoiding wildfires and wind turbines, and they must have intact forests there for overwintering.
It’s overwhelming for any one person to even imagine. And as monarchs join so many other creatures on the IUCN Red List of Endangered life, it may seem like there’s not much that each of us can do.
But there is something we can do. We can care for our local milkweed and watch it for monarchs. (The Western Monarch Milkweed Mapper project provides one way to submit monarch sightings. Journey North provides another.) We can celebrate that we have milkweed patches as extensive and healthy as West Mont’s. And maybe we can start some new patches.
From seed, it takes a few years for milkweed plants to flower. Buried shallowly in potting soil and kept well-watered, I’ve found that the seeds take about a month to germinate. Right now, outside my door, there’s a planter filled with milkweed seedlings I started this spring.
I don’t know if I’ll ever have a patch as big as West Mont’s. But in a few years, if monarchs haven’t gone extinct, I hope to walk out into my yard and find one laying eggs on my milkweed patch.
And in the meanwhile, I’ll be hoping that somewhere out here, in this valley, we have more than just one monarch caterpillar, growing up in a forest of milkweed.
Mahr, S. (no date). Common milkweed insects. Wisconsin Horticulture – Extension. https://hort.extension.wisc.edu/articles/common-milkweed-insects/
Rea, B., Oberhauser, K., & Quinn, M.A. (2010). Milkweed, monarchs, and more: a field guide to the invertebrate community in the milkweed patch. Union, WV: Bas Relief, LLC.