Milkweed. It’s not just for the monarchs.

Post by Jen Berlinghof

Being home more these past months has allowed my family copious time to observe the common milkweed (Asclepias syriaca) in our garden go through its life cycle day by day. We’ve witnessed the transformation from wily little sprouts in early summer to blooming beasts, with pompoms of eraser-pink flowers wafting perfume across the yard—even threatening to take over the footpath—by Fourth of July. Now in the sweet days of September, our milkweed is laden with swelling seed pods, ready to burst with floating seeds like so many little white parachutes scattered in the autumnal sky. The situation is similar in many of the Lake County Forest Preserves in northern Illinois.

The beautiful flowerhead of common milkweed (Asclepias syriaca). Photo © Lake County Forest Preserves.
The beautiful flowerhead of common milkweed (Asclepias syriaca). Photo © Lake County Forest Preserves.

Along with daily observations of the flora come the fun and excitement of watching the fauna that use our little plot. Like witnessing each stage of the milkweed’s growth, we’ve observed each stage of the monarch butterflies’ (Danaus plexippus) metamorphosis as well. My youngest son seems best at spotting the teeny, striated eggs on the undersides of leaves—he does have the youngest eyes, after all.

We spent one afternoon watching a plump monarch caterpillar devour a leaf, leaving only a pile of frass behind. One morning at dawn, we found the treasure of a frosty-green-and-gold, bejeweled chrysalis hidden in the patch. And we’ve spent countless summer evenings gazing at monarch adults as they floated back and forth through the garden, sipping the sweet nectar of the milkweed flowers in their own happy hour.

The monarch butterfly (Danaus plexippus), while iconic, isn't the only species that uses milkweed. Stock photo.
The monarch butterfly (Danaus plexippus), while iconic, isn’t the only species that uses milkweed. Stock photo.

While monarch butterflies are the best-known milkweed loyalists, there are other similarly orange-and-black insects that we observed using this important native plant. These insects are part of a club known as the Monarch Mimicry Complex. Membership entails feeding on toxic milkweed and wearing the same warning colors as monarchs, giving them protection from predators in return.

All of these milkweed specialists have evolved, in one way or another, to deal with the milky sap of the plant. It contains cardiac glycosides, which can be poisonous in large quantities. They even use the treat of toxicity to their own defense, advertising that they’re unpalatable and even dangerous to consume with their vibrant orange and black patterns. These act like a big, flashing danger sign to would-be pursuers.

This milkweed tussock moth caterpillar (Euchaetes egle) is quite noticeable against its milkweed host. Photo © Allison Frederick.
This milkweed tussock moth caterpillar (Euchaetes egle) clings to its milkweed host. Photo © Allison Frederick.
Milkweed tussock moth larva can skeletonize milkweed leaves. Photo © Allison Frederick.
Milkweed tussock moth larva can skeletonize milkweed leaves. Photo © Allison Frederick.

The milkweed tussock moth (Euchaetes egle) has voracious larva that skeletonize milkweed leaves in the blink of an eye. The species retains toxins from the sap like its fellow lepidopteran, the monarch. While monarch larva feed on young, fresh shoots, the tussocks seem to favor older shoots, so there’s rarely competition between the two.

The adult moth is a lackluster brown, yet the larvae is a showstopper. It sports long tufts of orange, black, and white hairs, warning daytime predators to stay clear and find some other food that won’t possibly make them vomit. But since the adult moths are nocturnal, they don’t really need the warning colors to evade their bat predators, who hunt using sound rather than sight. Instead, the milkweed tussock moth has developed an auditory warning in the form of ultrasonic clicks that bats have come to associate with a foul meal.

Large milkweed bugs (Oncopeltus fasciatus) feast on milkweed seed pods. Stock photo.
Large milkweed bugs (Oncopeltus fasciatus) feast on milkweed seed pods. Stock photo.
A small milkweed bug (Lygaeus kalmii) rests on a milkweed flowerhead. Stock photo.

Next up in the milkweed mimicry club are the milkweed bugs (Oncopeltus fasciatus and Lygaeus kalmii). These seed-specializing hemiptera, or true bugs, also store those damaging cardiac glycosides by consuming milkweed. In early fall, they congregate in large numbers on milkweed pods. They use straw-like mouthparts to inject enzymes into seeds, liquifying the plant food so they can suck it back up for a savory seed shake. The pokey proboscis only reaches so far. While they do devour the outer seeds, many inner seeds stay intact.

The large milkweed bug (Oncopeltus fasciatus), which is 0.75 inches long with a wide, black band across the center of its orange-and-black body, is migratory like the monarch. Its movements follow that of flowering milkweed. The small milkweed bug (Lygaeus kalmii) is only a half-inch long, sports a large red X on its back, and overwinters as an adult in the detritus of fields and gardens.

A milkweed beetle (Tetraopes tetrophthalmus) traverses a milkweed leaf. Photo © Allison Frederick.
A milkweed beetle (Tetraopes tetrophthalmus) traverses a milkweed leaf. Photo © Allison Frederick.
The black polka dots of the milkweed beetle (Tetraopes tetrophthalmus) are easily recognizable. Stock photo.
The black polka dots of the milkweed beetle (Tetraopes tetrophthalmus) are easily recognizable. Stock photo.

The last in the mimicry club we saw this year is the milkweed beetle (Tetraopes tetrophthalmus), whose orange-red and black polka-dotted body continues the aposematic tradition. Members of the order Coleoptera, these long-horned beetles have chewing mouthparts. They’re great for severing the large leaf veins of milkweed, which reduces the flow of milky sap that can gum up their chompers while they feast on the drained areas of said leaf.

Milkweed is not just food for these guys. It’s home as well. Milkweed beetles lay their eggs in milkweed stems near the ground. Once hatched, larva tunnel into the roots to feed during early fall before nodding off to overwinter in the rhizomes beneath the soil.

Purple milkweed (Asclepias purparescens) at Middlefork Savanna in Lake Forest. Photo © Lake County Forest Preserves.
Purple milkweed (Asclepias purparescens) at Middlefork Savanna in Lake Forest. Photo © Lake County Forest Preserves.

Since we’ll all probably spend even more time in our backyards and gardens this fall, it’s a good time to go investigate your own milkweed. See who’s sipping, slurping, chewing, and living on this significant native plant. Early autumn is also a good time to consider planting natives in your garden. There are many species of milkweed native to northern Illinois. This Chicago Botanic Garden guide will help you determine which ones might be best for your yard. You can also join us for a FREE virtual Native Plant Landscaping program on September 24, 7-8 pm to learn more about how to bring native plants into your garden.

The moth and the moon

Post by Jen Berlinghof

A full moon rises, a screen door slams shut, a katydid’s creaking calls echo, and a Luna moth (Actias luna) flutters in circles around the back porch light. We’re captivated by this green ghost of summer, concealed by broad leaves and seen rarely during the day, emerging at night only to mate for its few fleeting days of adulthood. How lucky it is that Luna moths live in the Lake County Forest Preserves in northern Illinois.

The bright green wings of the Luna moth (Actias luna) are instantly recognizable. Stock photo.
The bright green wings of the Luna moth (Actias luna) are instantly recognizable. Stock photo.
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A different kind of autumn apple

Post by Jen Berlinghof

Fall is the time of harvest here in the Midwest. Golden stacks of hay bales, farmer’s markets teeming with end-of-season produce, and above all, apples. But step away from the orchard and into an oak woodland and you’ll find a different kind of autumn apple: an oak apple gall. What looks like a small, lime-green, spotted apple dangling from an oak leaf is not a fruit at all, but rather a secret abode for a tiny wasp.

There are more than 50 species of oak apple gall wasps in North America. Each one creates a unique fruit-like structure that protects and feeds its eggs and larvae as they develop. Lately, I’ve been finding many dried, spent brown husks created by the larger empty oak apple wasp (Amphibolips quercusinanis) around the Lake County Forest Preserves in northern Illinois.

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The din of the dog days

Post by Jen Berlinghof

The dog days of summer are a bounty for the senses. We see the lemon-yellow of whorled sunflower blooms, taste the ripe flavor of a homegrown tomato, smell the spicy sweetness of bee balm flowers, feel the heat of the day and the cool of the evening. Yet the most quintessential sensation of these end-of-summer days is hearing the overwhelming cacophony of cicada songs around the Lake County Forest Preserves in northern Illinois.

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Leopards and tigers and bears!

Post by Jen Berlinghof

Around the first frost is the best time for spotting bears in the Lake County Forest Preserves in northern Illinois…woolly bears, that is! These fuzzy caterpillars succumb to a late fall wanderlust and can often be found traversing trails and roads, as well as climbing vegetation and nibbling a last few bites before winter sets in. They belong to the subfamily Arctiinae, commonly known as tiger moths. Their scientific name stems from the ancient Greek word arktos (“bear”), for the appearance of their hairy larvae.

A woolly bear caterpillar (Pyrrharctia isabella) found along the Des Plaines River Trail. Photo © Lake County Forest Preserves.

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Summer “buzz kill”

Post by Jen Berlinghof

The sun had set, the campfire was doused, and the food was stashed away for the night as my sons and I tucked ourselves into our sleeping bag cocoons, thoroughly exhausted in a way one can only be from a day spent entirely outdoors. Still, sleep would not come easily. The whirling drone of thousands of annual cicadas buzzed through the nylon walls of our tent loud enough to overpower our fatigue. I lay awake, thinking it odd the cicadas would be calling after dark, when I caught a hint of the rising full moon through the ceiling screen and realized they were staying up late to party with the extra light. One of my boys groaned, “Isn’t there anything that can stop these CICADAS?” As a matter of fact, the next day we found just the thing: a cicada killer wasp (Sphecius speciosus).

The author holds a dead cicada killer wasp in her palm. Photo © Lake County Forest Preserves.

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“Submarine cottages”

Post by Jen Berlinghof

Late spring and early summer are busy seasons for children visiting the Lake County Forest Preserves for pond study programs. The shorelines of ponds pulse with the excitement of students, nets in hand, ready to discover the macroinvertebrates teeming under the water’s surface. The most delightful find this season by students has to be what Henry David Thoreau once called the “submarine cottages” of caddisfly larvae.

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Dwindling lights

Post by Jen Berlinghof

At a recent Firefly Campfire at Ryerson Conservation Area, kids and adults alike were flitting around, as fast as the fireflies they were trying to catch. For many of the children, this was their first time experiencing the age-old summer tradition of capturing living light. While the woods that night sparkled like the fourth of July, many of the adults lamented that their yards didn’t have many fireflies—certainly not like the numbers they remembered chasing as children. Turns out they may be on to something.

group 4

Widespread anecdotal evidence of these dwindling evening displays have prompted scientists to take a look at possible reasons. One big culprit to the demise of these bioluminescent beetles seems to be the one thing that makes them so special: light. Continue reading

Des Plaines River Trail—Kilbourne Road to Independence Grove

Post by Jen BerlinghofIMG_7700

Our adventure to traverse the entire length of the Des Plaines River Trail continued with our trek from Kilbourne Road to Independence Grove Forest Preserve under the shining sun and heavy air of late summer. The air was heavy not only with humidity, but with the calls of cicadas, tree crickets, and katydids melding into a three-part harmony that signaled the end of summer. The air was also pregnant with the perfume of flowering plants. It was clear that this hike belonged to the bugs and blooms. Continue reading

Acorn abodes

Post by Jen B

My family went on a bike ride last weekend at Ray Lake Forest Preserve. All afternoon, rain sputtered on and off as the clouds played tag with the sun. After climbing up a steep hill, the sky darkened again and we sought refuge under a canopy of large oak trees. One of my sons yelped,”Ouch! That raindrop hurt!” We quickly realized it wasn’t a raindrop, but a storm of acorns jiggled loose by the wind, plopping down on us. The trail became littered with acorns, and the kids began grabbing them. Upon inspection, the boys noticed tiny round holes in many of the acorns—evidence that these nuts were homes to acorn weevils (Curculio spp).

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