The Corn Belt Tightens the Belt on Monarchs

One of my most vivid childhood memories from Iowa’s corn country is watching clouds of monarch butterflies dance around the milkweed patch by our back steps and finding caterpillars on the leaves. My brother and I raised them, as many kids do. They were the first butterfly I learned to identify, and just knowing their name made them more special.

Even as an adult, I watch eagerly for monarchs all summer. On a recent hike with local naturalist and author John Bates, he philosophized that “monarchs might be the next passenger pigeon.”  Indeed, their population has been in decline since 1997 (from a high of about a billion individuals, down to just 35 million) and a recent study warns that there is a greater than 5% chance that they will experience “quasi- extinction” (less than 1000 individuals) within a century.

In the past, it was easy to blame our southern neighbor for the declines. Illegal logging with mafia-like techniques in the mountainous butterfly preserves of Mexico was a major problem, but it has largely been addressed by the Mexican government. There is still more to be done with supporting the local economy so that the locals won’t need to extract resources from the protected forests, but the biggest challenge to the monarch’s struggle for survival is no longer across an international border. It is right here in the US, in the every-more-productive Corn Belt where I grew up.

The incredible migration that monarchs are beginning just now will culminate next spring in a flurry of reproduction. The butterflies that fly south from Wisconsin and Minnesota this September will overwinter in the remote oyamel fir tree forests in the mountains west of Mexico City. In early spring, those same monarchs will head north again – hoping to lay their eggs on spring-fresh milkweed plants in Texas before they breathe their last butterfly breath.

But what if there isn’t any milkweed? Drought, cold weather, and habitat loss have all been recent issues. And the challenges continue as generations of monarchs leap-frog north into the Midwest – into the infamous Corn Belt. A majority of monarch butterflies on the Mexican wintering sites are born in the Corn Belt. Since the first genetically modified (GMO), herbicide resistant soybeans were introduced in 1997 (with GMO corn following shortly), there has been an 80% decline in milkweed in the Midwest, and a concurrent 81% decline in monarchs. In Iowa, one biologist estimates there has been a 98% reduction in milkweed on the landscape.

 “What we’re seeing here in the United States is a very precipitous decline of monarchs that’s coincident with the adoption of [herbicide-resistant] corn and soybeans,” says Chip Taylor, founder of Monarch Watch.

While GMO products have garnered support among some scientists for their apparent food safety, the changes that GMOs have caused in our farming practices and the subsequent habitat loss for many organisms (not just monarchs) are a significant bit of collateral damage. More GMO crops – some resistant to several types of herbicides—are in the development pipeline.

It’s not just GMOs and glyphosate herbicides. Farming practices have changed a lot since my Grandpa Warren hunted pheasants among fencerows in central Iowa. With corn prices soaring, bigger equipment, and bigger farms taking the lead, and subsidies for ethanol taking the place of the Conservation Reserve Program (CRP) subsidies, more of the land is under cultivation than ever before.

“Overall, genetically modified, herbicide-resistant crops have increased the current, and predicted future, extinction probability of monarch butterflies in eastern North America,” agree a team of international scientists writing for the Journal of Animal Ecology last year. They found that, while winter mortality is still an issue to contend with, the loss of milkweed in the Corn Belt is the greatest factor precipitating monarchs’ population declines. That same article admonishes that addressing these challenges is “the highest conservation priority.”

There is some good news. Favorable weather and efforts by back-yard conservationists like Eve Depew and Cec Peterson have helped. Chip Taylor just wrote in his most recent Monarch Population Status blog post at MonarchWatch.org, that “The number of eggs found …now leads me to suspect that the migration through the upper Midwest will be better than any migration seen since 2011.” A year of population growth will be very welcome.

Habitat loss is the biggest problem, and you can help. Every extra back-yard milkweed plant and un-sprayed flower garden could host one more caterpillar, and provide nectar for hundreds of pollinators. Getting the Department of Transportation, the Forest Service, and the National Park Service involved can offer access to even more acres.

But gardens like these “are not going to make up for 25.5 million acres of additional corn and soybeans,” says Chip. Large conservation efforts – and sustainable farming practices – also are necessary. You can help there, too, by choosing carefully at the grocery store, by supporting the organizations doing good work, and by letting your representatives at all levels of government know that you value conservation efforts. Several concerned groups banded together last year to ask that the monarch butterfly be listed as “threatened” under the Endangered Species Act, which would increase funding and research into their recovery.

Should we do all of that work, and make all of those sacrifices just to save a single species of beautiful, amazing butterfly? No! We should work to save the monarch because in doing so we will also be saving ourselves, our planet, and the futures of kids like Eve.

Monarchs are experiencing steep population declines, mostly due to farming practices in the Corn Belt. Why should we care? For the futures of kids like this one! (Who just happens to be my nephew Derek, from the heart of corn country in central Iowa.) Photo by Larry Stone. 

Monarch Migration Miracles and Challenges

“Absolutely spectacular. Nothing compares with it.” Effused Cecilia Peterson as she sat down to tell me about her three visits to the monarch butterfly overwintering sites in Mexico. At first glance, Cec (pronounced “cease”) – a retired elementary teacher and avid gardener – doesn’t have much in common with Eve Depew, a seven-year-old girl raising monarchs in Hayward, WI. But as Cec continued, describing the amazing experience of being in a forest with butterflies practically dripping from every trunk and branch, the enthusiasm and wonder that lit up her weathered face was exactly the same as Eve’s. They have yet to meet, but these girls are like two peas in a pod.

In fact, Cec can more than empathize with Eve’s efforts. Starting in the mid-1990s, all the fifth graders in Cec’s inner-city Duluth, MN, classroom raised a monarch from egg to adult in a plastic shoebox on their desk. “That experience with nature overrode any behavior problems,” reminisced Cec.

In the beginning, students like Cec’s would have only learned about the mystery of where monarchs go in the winter. While the overwintering sites have been known to locals for many years, science only discovered them in 1975.

Since then, the students all over the country have learned about the amazing migration that monarch’s undergo, and the remote oyamel fir tree forests in the mountains west of Mexico City where they rest from December to April. On steep, southwest-facing slopes, ten-thousand feet above sea level, the temperatures are just right. There, in the cool, moist microclimate in the trees, monarchs bide their time. The forest is both their umbrella and their blanket. The dampness helps keep them from dehydrating, while the canopy prevents dangerous wetness. Moderate temperatures under the forest cover prevent them from freezing to death, while still being low enough to slow their metabolism, and stretch out their limited fat reserves as long as possible. On warm days, they will fly nearby for a nectar snack and drink of water.

Dangers still abound in the forest, though. The canopy can’t totally eliminate freezing temperatures or ice storms, and especially when a cold snap follows rain, wet butterflies may freeze. One such storm happened the year that Cec returned to the forest for her second visit. Instead of ethereal beauty, she remembers the horrendous stench of rotting butterflies. As our climate changes and extreme weather becomes more common, scientists are worried that those dangerous storms and temperature fluctuations will happen more frequently.

Compounding the weather issues are pressures on the forests to provide useful products for local residents. Although the wintering areas have been set aside as Biosphere Reserves, monitoring shows illegal logging is taking its toll. “At night, in my hotel, I could hear HUGE logging trucks rumbling down the mountain from the butterfly groves,” lamented Cec. Because of that, many of the monarch conservation efforts have been aimed at protecting these winter refuges. While the large-scale illegal logging practices have largely been brought under control since Cec last visited, the thinned forests and continued subsistence harvest of the trees allows more moisture to get through to the butterflies, and they retain less heat.

Some natural predation occurs in the mountains as well, since a couple types of birds and one species of mouse have adapted to eating the sleepy butterflies. This is no mean feat, since the toxins that caterpillars acquire from milkweed plants survive metamorphosis and remain in the adults. The critters have adapted, though. One mouse can eat about thirty-seven monarchs a night in the oyamel forest.

With almost all of the continent’s monarchs concentrated in one region (another smaller population overwinters in California), they become vulnerable to a single storm, drought, fire, disease, or human transgression.

The concentration of monarchs also brings in a high volume of ecotourists, who mean well, and who can help support the local economy, but who can sometimes impact (literally, with their feet) the very beauty they came to revere.

Despite all this, many monarchs survive the winter. The warmth of spring triggers a mating frenzy, which also triggers their reproductive diapause to end. Females can mate before they are sexually mature, and both mating and the presence of milkweed seem to speed up their development.

In mid-March, these long-lived butterflies begin the last leg of their journey. Their destination is fresh, spring milkweed in the southern United States. Here, at the tail end of their 3,000-mile, 8-month journey, comes the most significant challenge they’ll face. Seven-year-old Eve knows about it. Cec gardens because of it. And there are things that you can do to help. More about that next week.

Overwintering monarch butterflies in a preserve outside of Angangueo, Mexico, completely cover some trees. Photo from Wikipedia. 

Monarch Migration Begins

I see them everywhere now. Deep orange with black trim, monarch butterflies dance among the wildflowers we planted for them. Two, then three, then four! Are they fighting or loving as they bang their delicate wings? Then, calm for an instant, they alight on the many-petaled clusters of butterflyweed and sip its abundant nectar.

I look closely while they are still. One, at least, is a male. I can see the slender black lines with a swollen black dot on each of his hindwings as he unfurls his slim proboscis and drinks deeply through its hollow center. This amazing tube is made of two long, C-shaped channels, which the butterfly joined together with tiny hooks and fringes after he emerged from his chrysalis. Even now, if his proboscis gets clogged with sticky nectar, he can unhook the two channels to clean them.

As a female – with robust black lines – explores a nearby butterflyweed, I try to watch her feet. Butterflies taste through their “toes,” identifying their platform as a milkweed, and also determining its quality as baby food. While this low, bushy plant looks nothing like common milkweed, it is a close cousin, and one of the few host plants that can nourish monarch caterpillars. Each female lays an average of 700 pinhead-sized eggs during her two-to-six-week lifespan.

Leaning in closer—hoping to catch her in the act of egg laying—I startled her into flight instead. Monarchs, with their compound eyes, have almost 360 degree vision, and use it to detect predators even with their head in a flower.

The eggs that are laid now, in mid-August, will become butterflies who live longer and fly farther than their parents. The eggs laid now will become the migratory generation, and take part in an amazing, two-month-long journey. Monarchs produce three to four generations per summer, and the population grows with each new generation. By early fall, monarch numbers are at their peak.

The shortening days and cooler nights of fall trigger many seasonal changes in the northwoods. Leaves begin to show their brilliant fall colors, birds stop singing and begin to migrate. Many insects enter an overwintering phase of their life cycle. Monarchs are no different. The onset of fall triggers the larvae and pupae of monarchs to enter "reproductive diapause." They metamorphose into pre-pubescent butterflies who cannot yet reproduce, but who are ready to journey south.

This happens all across the monarch’s habitat at slightly different times. Canadian butterflies begin their migration earlier, swirling through Wisconsin at about the same time that our butterflies are ready to head south, too. Eve Depew, the seven-year-old scientist from Hayward, WI, who has been raising monarchs all summer, has more than a dozen chrysalids that are close to emerging. She will name and photograph each monarch, then send them out to start their journey.

The building wave of peak monarch abundance hits us here in early September. The surge reaches Houston, Texas, in mid-October, and the butterflies’ destination – the Transvolcanic Mountains of central Mexico – in mid-November.

These young butterflies have never seen their destination–nor did their parents, grandparents, or even great-grandparents. Flying only by day, they navigate with some combination of sunlight (the ability to see polarized light lets them know the position of the sun, even when hidden by clouds), and magnetism. Tiny “Johnston’s organs” at the base of each antenna are sensitive to stretching. They are used to detect wind and gravity, and maintain balance and orientation during flight. They may also be able to detect the Earth’s magnetic field.

Even with such sensitive instruments, it is a mystery how these tiny (and thus tiny-brained) butterflies even know where they are supposed to end up.

Watch for the change in monarch flight patterns as fall approaches. Their erratic fluttering from flower to flower is replaced by directional flight. Heading south, they rise on thermals of warm air, and soar on wind currents just like birds. Like a hot-air balloon pilot, they fly at the altitude with the best wind direction. And they avoid flying on days with a strong headwind. Scientists using a model butterfly have discovered that the forces from tiny eddies of air created during each wing flap generate lift. By using all of those efficiencies and by feeding regularly, monarchs are actually able to gain weight on their two-month-long trip, and can travel at least 265 miles in a day!

Entering the winter with plenty of fat stored in their abdomens, millions of monarchs prepare for a long wait. This migratory generation must face a host of perils not encountered by their parents. And the continuation of the species rests on their tiny shoulders. (More about this next week.)

Do you have monarch eggs, caterpillars, or butterflies in your yard, too? We may be in the presence of the greatest generation.

Monarchs that are born at the end of the summer don’t fully mature. Instead, they enter “reproductive diapause,” and live longer than any other generation – long enough to fly to Mexico for the winter. The thicker black lines on the butterfly mark her as a female. Photo by Larry Stone.

Northwoods Lobsters

I don’t know if it’s been dry near you, but my house has been skipped by too many recent rainstorms. So when the gentle hiss of liquid on leaves permeated my kitchen window screens, I donned a bright yellow slicker and headed out into it. The joy of a slow, quiet walk in the damp woods reminded me of Mary Oliver’s poem, Lingering in Happiness. “After rain after many days without rain,” she writes, “it stays cool, private and cleansed, under the trees…”

Colors were muted in the gray dusk, but scents were made vibrant by the splash of drops sending dust molecules skyward, where the damp air stuck them to the insides of my nose. I breathed deeply, again and again, on my way down the driveway. Sweet, green raspberry leaves. The tang of the bog. Wet asphalt. Wet gravel. And then, the earthy bouquet of the woods.

“The dampness there, married now to gravity, falls branch to branch, leaf to leaf, down to the ground where it will disappear—but not of course, vanish, except to our eyes,” continues Mary Oliver. So focused was I on my nose, things did seem to almost vanish to my eyes. Until, that is, a flash of bright orange switched me between senses.

The oddly shaped blob of color right next to the trail didn’t look like much. But I knew instantly that it was treasure. In fact, it was a lobster, right here in the center of the continent. Not a crustacean, mind you, but a mushroom.

Lobster mushrooms, like many good things, are actually the result of a relationship between two living things. The orange-colored fungus, Hypomyces lactifluorum, parasitizes the mushroom of another fungus, and in doing so creates a tasty treat. Neither of the common host mushrooms is edible on its own. While not poisonous, Lactarius piperatus is reported to have an intensely peppery flavor. Russula brevipes, the other common host, is also harmless, but has a crumbly, Styrofoam texture that would be unpleasant to eat. Hypomyces not only renders a pleasantly firm, dense texture, it also neutralizes the peppery flavor and imparts an interesting seafood flavor.

Lobster mushrooms are a delight for beginning mycophiles, since they and their hosts are easy to identify. They are on the short list of mushrooms that I’ll eat without expert help. The outer surface is bright orange and looks slightly pimply – those dots are the reproductive structures for the parasite. Breaking open the gnarled mass of what used to be a mushroom cap, I found an appealing white center.

Continuing down the trail, I started to notice plain white mushrooms all over the woods. “Puhpowee was here,” I thought to myself. An Anishanabe word, it means “the force which causes mushrooms to push up from the earth overnight.” These must be the un-parasitized cousins of my lobster. But which host were they?

The first crumbling snap of the stem made me think of a Styrofoam Russula, but then I noticed milky sap oozing from a broken gill under the cap. This Lactarius was lactating. “So how peppery is the milk?” I wondered. After debating the risk of eating a raw wild mushroom (something that is not advised), curiosity won out and I touched the tip of my tongue to the milk. It was spicy, but not any worse than a peppercorn stuck in your teeth, or an extra dose of wasabi on your sushi. Eating a full bite would have been certainly been painful.

With tongue burning, nose humming, eyes flashing, cool raindrops tickling my bare knees, and the patter of rain filling my ears, I hurried back down the trail toward my kitchen. Although I’ve known about the edibility of lobster mushrooms for several years, I’ve had yet to taste one.

Soon my favorite cast iron skillet was sizzling with butter, and a pile of fresh garlic was mounded on the cutting board. Into the pan went the bowl of cut and cleaned lobsters. Into my nose rose a savory perfume. Into my mouth went the first hot morsel with its bright orange rind. Without garlic, it was bland, but pleasant. It was a nice experiment, but not dinner. In went the pile off the cutting board. The flavors of garlic and butter warmed my cool evening as the rain drummed harder on the leaves.

Lobsters in the Northwoods. After rain, after many days without rain, you never know what you might find in the woods.

 

Bright orange lobster fungi sometimes hold the shape of their host mushroom, but the orange rind on the outside is actually a parasitic fungi that renders inedible hosts tasty. Photo by Britt Bunyard.

In the background sits an un-parasitized Lactarius piperatus. In the foreground you can see the pimply orange rind of parasitic Hypomyces lactifluorum that renders the brittle white flesh of the Lactarius edible. Together, they become the lobster mushroom.  Photo by Emily Stone.

Phantom in the Forest

“What’s that!?” exclaimed Ellie. “Where?” “What?” “I see it!” “Weird!” came the jumble of replies.

Six strong girls were relaxing on the riverbank, philosophizing about how they came to care about nature. This group of high school girls from the Northland College summer program had just paddled a short but beautiful stretch of the Namekagon River, taking time to catch aquatic insects, learn about river geology, and check out some amazing flowers in bloom.

Now, something crazy was interrupting our conversation. A wisp of a creature floated in and out of view. For not appearing to be a strong flyer, it certainly sped along faster than the eye could focus on its form. It was just the size of the hole in your fingers when you make the “ok” sign, and barely more substantial than that empty space, too.

The mystery came and went all afternoon, interrupting our discussions as we all tried to get a better look at it. Black and white bands on the thread-like legs broke up its outline, and allowed it to disappear against the backdrop of vegetation. We tried to catch it, but all depth perception failed. Finally, I too, had to fade into the river and return home.

Back in my kitchen, movement at the window caught the corner of my eye. There it was again! This time, with the internet close by, I was able to solve the mystery. Aptly named, these creatures are phantom crane flies.

Last summer I wrote about the much more substantial giant eastern crane fly. Phantom crane flies are in a related family all their own, and are known for their ghostly ability to disappear. Their preference for the dense and shady vegetation along wetlands aids in their habit of vanishing into the background.

When you finally do see a phantom crane fly, they are no less astonishing. All legs are held perpendicular to the ground when they fly—spread out in a big circle—making them look a little like a floating snowflake.  They barely use their wings when flying. Instead, their legs are light and hollow, and have inflated sections at their tips that catch the breeze like little sails.

This low-energy movement is useful for an insect that isn’t known to eat as an adult. Mating is likely their main goal, and it occurs either in mid-air, or with the female clinging daintily to a leaf. In either case, the smaller male is suspended from the female’s abdomen, and doesn’t seem to fly or perch at all during the process.

The female then dips the tip of her abdomen in water or mud and deposits over 300 eggs at a time. Small worm-like larvae hatch, burrow into the muck, and then breathe air from the surface through a long siphon tube. They eat debris and organic matter before metamorphosing through the pupa stage and becoming the only slight less cryptic adult.

In the process of sharing the answer to our phantom encounter with the girls, I reflected back on our insect-interrupted conversation about why we care. Time in nature and encounters with wild things were two common themes. And, whether the girls realize it or not, I believe that it is also their willingness to be curious, and to be excited by the mysteries of the world that will keep their love of nature alive.

“If I had influence with the good fairy who is supposed to preside over the christening of all children, I should ask that her gift to each child in the world be a sense of wonder so indestructible that it would last throughout life.” --Rachel Carson

Phantom crane flies are fairy-like creatures with tiny wings and tiny sails on the tips of their black-and-white legs. Look for them in dense wetland vegetation.
Photo by Brandon Woo.

The Brookies of Cap Creek

“Stick a toe in the water,” dared WDNR Fisheries Biologist Max Wolter with a sly grin. The teenage boys (and one mom) who had joined me on this adventure hesitated for only a second before taking the dare. “Wow, that’s cold,” was the general response. We’d just dipped our feet into Cap Creek, a spring-fed tributary of the upper Namekagon River, and that cold water was part of what drew us here. The cold water is also what draws native brook trout here, and this little stream hosts one of the best brook trout habitats on the Namekagon.

Every year the WDNR collects data on the number and size of trout in this stream. They accomplish this not through the elegant casting of a fly rod like we learned about a few weeks ago, but with wands that send currents of electricity through zipping the water, and nets to scoop the temporarily stunned fish up from the bottom (they don’t float when stunned as many people think). Fish shocking is a common research technique—and one that holds quite a bit of intrigue for kids of all ages.

When we’d arrived at the Cap Creek Landing on the Namekagon River, the three DNR biologists were sitting at the landing with their little research boat, counting and measuring fish. Max looked up apologetically, saying “This might take a while; we just caught an unusually high number of trout in our first sweep.” So we stood there watching and listening as two biologists pulled fingerling trout out of their nets, dropped them one at a time into measuring troughs, and called out lengths to Max, who recorded the numbers on his data sheet. While a bit tedious, this was the reality of science in action.

Things got more exciting when Max brought out a small aquarium on a tall pole. He sunk the pole in the sand, and then grabbed good-sized brook trout out of a net. Now at eye level, we could admire the beauty of this incredible fish – the only truly native trout on the Namekagon. A pattern of yellow and olive-green markings was overlain by scattered red spots, each with a halo of pale blue. The pectoral fins were a lovely shade of orange. I don’t think I’ve ever seen a more beautiful fish.

According to Max, they usually only find a dozen or so trout in this section of the Namekagon River, just below the mouth of Cap Creek. Today, they found close to a hundred. Of course we asked why. “The mild winter, he replied immediately. “All the little ones survive the winter better when it’s short and there’s not as much ice buildup.” He continued, “It’s neat to have long term data because you can look at how the weather impacts trout,” said Max. “In all the really long winters we had bad trout numbers. In all the short winters we had good numbers. You can start to see patterns.”

Of course, it’s not just the length of our winters that affects trout populations on the Namekagon and its tributaries. “Trout are fragile,” remarked Max. “They need cold, pure water, good habitat, and few contaminants.” In the old days, the Namekagon River provided all of that. Way back in 1831, the explorer Henry Schoolcraft noted the abundance of brook trout in the Namekagon River, even in the warm summer months. Later, in 1883, as tourism became a local industry, one fly-fisherman claimed that “All trout streams in the state must yield the banner to the noble and lordly Namakagon.”

The logging boom of the late 1800s and early 1900s changed that. With the large trees felled off its banks, sunlight warmed the river. Extra sediment washed into the channel and covered up some of the cold water springs that used to moderate the river’s temperature. Woody debris that previously provided cover was removed from the channel. Logging dams pooled water and allowed it to heat up before flowing downstream. None of those changes are good for a fish that can’t survive in water above sixty-eight degrees.

Cap Creek had its own set of challenges. In the 1950s, a trout farm diverted the water of this spring-fed stream into several excavated ponds. Although trout thrived in the hatchery, no native fish frequented the creek. In 1988, the National Park Service acquired the trout hatchery and began major restoration work. Cap Creek was restored to its original channel. Extra sediment was removed, revealing groundwater springs which today we watched bubbling up from the sand. They help keep the stream at a steady fifty degrees all year round. Logs were placed in the channel to provide cover and shade for the fish. “They work, too,” said Max, pointing to one of the logs along the bank, “we got seven or eight adult trout out of that spot when we came through with the nets.” He continued, “This is a great example of what you can to do restore something.”

Native prairie plants higher on the bank swayed in the breeze. They were part of the restoration, too. But all along the water’s edge were carpets of forget-me-nots, a European species that has escaped and spread along many stream banks. I commented on it being an invasive. “Well,” spoke up one of the biologists, “invasive or not, it’s good cover. That’s where all little fish are hiding when we came through.” “Plus it sure is pretty,’ noted one of the boys.

There’s another introduced species here, too, that may not be so bad. European brown trout were stocked here starting around 1883. They do better in warmer water, and frequent the main river channel more than the chilly waters of Cap Creek. The researchers only caught a few brown trout on their sweep up the creek.

By some accounts, brown trout eat the young brookies, and push them out. But with the changes in water temperature brought about by logging, and the uncertain future of climate change (which predicts our temperatures in northwestern Wisconsin to be more like eastern Kansas by the year 2095), brown trout may have a role to play in the ecosystem, especially outside areas like Cap Creek where the brookies thrive in water too cold for the browns. The interagency Fisheries Management Plan for the Namekagon and St. Croix Rivers describes the introduced brown trout as “an ecological surrogate for brook trout” and states that “brown trout are now a keystone species, maintaining the basic biological integrity of this fish community.”

Sticking our toes in the chilly stream today, we touched just a bit of a common current that runs through the history of North America. From abundance to exploitation; habitat loss to restoration; and now the preparation for an uncertain future…It is sure to be an upstream battle to conserve and create a world we – and the trout – will like living in.

Brook trout are members of the char subgroup of the salmon family. Char typically have a dark base color with light spots in contrast to true trout (like brown trout), who have light base colors and dark spots.  Photo by Emily Stone.

Brook trout are members of the char subgroup of the salmon family. Char typically have a dark base color with light spots in contrast to true trout (like brown trout), who have light base colors and dark spots. 

Photo by Emily Stone.

DNR fisheries biologists led by Max Wolter (left), pull their boat with the electrical equipment in it upstream. Waders protect the men from the electricity that emanates from their wands. Temporarily stunned fish are scooped up with the nets and dumped into a bucket on the boat until their data can be collected. Photo by Emily Stone.

Monarch Chrysalids

A week went by when I didn’t have a chance to check on the monarch caterpillars near the Cable Natural History Museum’s front door. So after I’d waved goodbye to the last fly-tying, canoe-paddling, snack-eating boy, I deserted the pile of dirty camping dishes in the sink, and rushed out to check on my caterpillar crew.

The milkweed looked like it had seen better days. Many leaves were completely missing, while others were chewed down to a yellowing stub. While the evidence of their voracious eating was all around, a quick glance revealed no caterpillars. So I searched harder and harder; checking under each leaf, peering under the pendulous flowers, until I satisfied myself that the caterpillars were nowhere to be found.

A little research confirmed what I suspected. Once a monarch caterpillar has reached its final instar and stops eating, it enters a wandering stage and travels some distance from its host plant to find a safer, less visible place to pupate. Somewhere in the sweetfern thicket on our hill, hang four delicate, pale green chrysalids. (Side note: If you’re wondering about my spelling, both chrysalis and chrysalid are correct terms for the pupa, and chrysalid is easier to make plural.)

Since I had hoped to have a front row seat during the caterpillars’ transformation into adults, I was more than a little disappointed. The blinking orange light of my voice mail inbox soon changed that.

Bob Olson, one of my readers, just had to tell me about his granddaughter, Eve Depew. This bright-eyed seven-year-old is raising over 50 monarch butterflies on her back deck in Hayward, WI. She (with the help of her supportive parents) plans to save the monarchs from extinction.

As I chatted with Eve and her mother, Brianne, near the wood and netting butterfly nursery that Eve’s dad built, we kept one eye on the action. A neat line of chrysalids dangled from the sunny side of the frame, interspersed with crumpled, empty shells and their orange-winged owners. (It was too cold to release the seven new butterflies today.)

Hanging in one corner, a brightly striped caterpillar stuck out like a sore thumb. He’s in the J” spouted Eve, “I hope he changes soon!” Looking closer, she noted how the white stripes were looking greenish, and amended her exclamation, “I think he’s almost ready!”

While this caterpillar still looked more like a larva than a butterfly, some important changes had already taken place. During the wandering stage (when Eve must rescue wayward caterpillars off the deck furniture), veins develop that will supply his wings with fluid. As the caterpillar pupates, each wing is shaped and ready for adulthood.

During a pause in the conversation, we looked over to see that the caterpillar’s J was relaxing. “He’s ready!” announced Eve, swinging her blonde braids over her shoulder.

Sure enough, the skin near the back of his head had begun to split, and a small triangle of green showed through. Almost imperceptibly, this triangle grew as his exoskeleton sloughed off and crumpled into a wad near the silk button that attached it to the wood. It is easy to think of a caterpillar spinning a chrysalid around itself, but the delicate green shell is actually the body the caterpillar reveals during its last molt.

I stuck my nose up to the screen for a front row seat, while mother and daughter giggled together, narrating the action and imitating the energetic wiggling and twisting that the caterpillar must do in order to kick off the last of its old clothes without falling. This is no easy feat, as the monarch must pull a small, stick-like cremaster out of its exoskeleton and poke it into the silk button to secure its attachment for the long haul. This is a risky time for the monarch, and Eve told me sadly of one pupa that failed this step, its life ending in a pile of mush on the ground.

The newly-formed pupa looked lopsided to me, and upside down. Eve assured me that this was normal. In a few hours, the chrysalid’s exoskeleton would shape up and harden off.

Throughout my stay, both mother and daughter impressed me with their detailed knowledge of the life cycle. Only when I asked about the mysterious changes that happen inside the chrysalid did Eve furrow her brow and say “I just don’t know.” Scientists are only just beginning to figure out the details themselves.

While the pupa is certainly soft and vulnerable as it forms, it isn’t quite the soup of cells that some people imagine. At no time do all the body parts break down, although the chewing, crawling muscles of the caterpillars are reduced to liquid and reformed into the flight muscles of a butterfly. During the final caterpillar instar, clusters of cells called imaginal disks started to grow rapidly. Besides the wings, they have already formed a beating heart, a respiratory system, antennae, legs, and a proboscis. Those parts and others just need more time to develop fully, and old caterpillar parts need to be digested and reabsorbed.

As I sat transfixed by the show, Eve told me how she gathers fresh milkweed (complete hitchhiking eggs and caterpillars) from a neighbor’s field every day, and cleans the copious caterpillar poop out of the enclosure. “She spends hours out here,” her mother said with a proud smile. “I think she’s going to grow up to be a scientist.” In my opinion, this little caterpillar is already well on her way.

For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new exhibit: “Lake Alive!” opened May 1, 2015, and will remain open until March 2016.

Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com.

As the developing monarch butterfly gets close to completion, the exoskeleton of the chrysalid becomes transparent and brightly colored wings show through. Photo by Emily Stone. 

Six-year-old Eve Depew is raising more than 50 monarch butterflies in an effort to protect them from weather, predators, and all the dangers of the wild. She hopes her efforts will help their populations recover. Photo by Emily Stone.