Field report — Speak for the Trees

June 26, 2026

and have converged on the lakefront milkweed patches this June — a quiet milestone marking the transformation of this urban edge into essential breeding habitat. Three monarch sightings and four beetle records in recent weeks document what appears to be active reproduction on — a coupling that persisted through the Midwest's agricultural intensification but has grown increasingly rare.

Over the past three decades, the application of herbicides to corn and soybean crops has stripped milkweed from hundreds of thousands of acres across the region, collapsing the landscape resources that monarchs and their specialist associates once took for granted. The migration corridor now depends on fragmented urban and semi-wild refuges like this one. What was once common is now significant.

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Monarchs laying eggs on milkweed

June 26, 2026

The common milkweed plants along the edges of Chicago's green spaces are at their best right now. The leaves are broad and flat, dark green, still soft enough to bend without snapping. This is what a female monarch is looking for when she moves low over a patch of vegetation in early summer, and if you watch one long enough, you can see exactly how she decides.She lands on a leaf and drums it with her front feet. This is not random movement. Her feet carry chemical receptors that detect the milkweed's latex compounds through contact, confirming the plant before she commits. She may check several leaves on the same plant, or leave and try another patch entirely. When she finds what she wants, she curves her abdomen under the leaf and deposits a single egg, pale green and ribbed, smaller than a sesame seed, on the underside. Then she moves on. A single female may lay several hundred eggs over the course of her adult life, but she places them one at a time, spread across as many plants as she can find. This distributes the risk. A caterpillar that strips one plant does not compete with its siblings on the next.The milkweed's role here is not passive. The same latex that the monarch detects through her feet is a sticky, bitter sap that fills channels running through the leaves and stems. Most insects avoid it. A young monarch caterpillar, when it hatches, deals with this by cutting a circle into the leaf surface before eating, draining the latex from that section so it can feed safely. Older caterpillars learn to sever the leaf's midrib at the base, blocking the flow to the whole leaf. The plant is not helpless, but the monarch has worked out how to eat it anyway, and the cardenolides in the latex accumulate in the caterpillar's tissues as it feeds, making the caterpillar itself unpalatable to most birds. The monarch does not merely tolerate the milkweed's chemistry; it borrows it.The red milkweed beetle is doing something similar in these same patches right now. It chews a trench around the midrib before feeding, stopping the latex flow the same way the caterpillar does. Both insects have arrived at the same mechanical solution independently, and both carry the plant's toxins in their bodies. The beetle's red and black coloring advertises this to predators just as the monarch's orange and black does. Neither insect is the other's competitor in any serious sense; milkweed patches in early summer can support both, along with the various bees and wasps that come for the flowers, which are just beginning to open on some plants now, the pink-purple clusters heavy and fragrant above the broad leaves.For the monarchs in this area, the early summer generation is the one that matters most for local reproduction. The butterflies that arrived here in late spring came from overwintering sites in central Mexico, and they have already moved north ahead of the milkweed's emergence. Their offspring, the eggs being laid right now, will be the ones that hatch, feed, pupate, and emerge as adults here in Chicago. Those adults will produce another generation before the season turns. It is the last generation of the summer, not these, that will make the long flight south in autumn. The eggs on these milkweed leaves are the beginning of that chain.Common milkweed grows in disturbed ground, roadsides, vacant lots, and park margins, the kind of habitat that exists in fragments throughout the city. The patches near the Loop are small by rural standards, but monarchs find them. Look for the plants where mown grass gives way to rougher growth, the leaves big and paired, the stem thick. If you find a patch, check the undersides of the leaves. The eggs are easy to miss, but they are there.

June 29, 2026

and are patrolling the lagoons on the West Side this week — both tolerant species adapted to marginal water quality. This preference for resilience over choosiness makes ecological sense: all three of the major lagoons here are officially designated as impaired waterways, and none have cleanup plans in place.Streamflow has dropped to just over 12 cubic feet per second, roughly a third of the long-term average of 41 feet per second. Warm, still water holds the least dissolved oxygen of the year, creating conditions that only generalist dragonflies can exploit reliably. The visible presence of these species is less a sign of health than of their extraordinary tolerance for stress.

July 13, 2026

Compass plant is blooming at 46 sites citywide since May — lakefront to Southwest Side. Its 15-foot taproot takes a decade to establish; when it flowers, the soil has earned it. Settlers once navigated the Illinois prairie by its north-south leaves.

More about Monarchs

Breeding monarchs fill milkweed blooms across southern Maine

July 11, 2026

are moving through milkweed blooms from Westbrook to Scarborough in a wave that will ripple all the way to Mexico in the fall. These are the breeding adults of the generation that makes the long migration — the population checkpoint that determines how many survive the journey south.The timing is tight: milkweed flowers opened around July 5th, and monarchs began visiting the blooms just days earlier, suggesting the plants and insects are synchronized by the same weather rhythms. Sightings this summer, from mid-June through mid-July, have scattered across the region — Westbrook, Scarborough, Portland, Buxton, York, Cape Elizabeth — reflecting how deeply the breeding cycle now depends on roadside milkweed patches.What makes this urgent: the species was listed as threatened in December 2024 after an 80-percent population collapse over recent decades. Monarchs have long relied on milkweed that Wabanaki people shaped and tended; today, those same roadsides and margins are often the only habitat left. For now, the plants are blooming and the monarchs are finding them — but the margin between recovery and further decline is narrower than any butterfly's wing.

More about Red Milkweed Beetles

Red milkweed beetles on summer flowers

June 26, 2026

The common milkweed along the roadsides and field edges near Mechanicsburg is in full bloom right now. The flower clusters are tight pink-purple spheres, each one made up of dozens of small individual flowers with reflexed petals and a fused central crown. If you're near a patch, you can probably smell them from several feet away, a heavy sweetness that carries on still air. Look closely at those flower heads and you may find what's there most days at this point in early summer: red milkweed beetles, one or several, moving slowly across the blooms.The red milkweed beetle is a longhorned beetle, stocky and about three-quarters of an inch long, with bright red wing covers marked by four black spots. Its antennae are nearly as long as its body, banded in black and red, and it holds them angled forward as it walks. This beetle does not visit milkweed the way a generalist insect might, stopping by for a meal before moving on. It is specifically and deeply tied to milkweed. The larvae hatch from eggs laid in the soil near milkweed roots and spend their first year underground, chewing into the root tissue. The adults that emerge in early summer return immediately to the plant, feeding on the flowers, leaves, and stems. The whole life cycle runs on a single genus. When milkweed is present, the beetle is usually present. When milkweed is absent, the beetle is not.Milkweed produces latex, a sticky white sap that runs through the leaves and stems under pressure. For most insects, this latex is a serious problem. It gums up mouthparts, hardens quickly on contact, and contains toxic compounds called cardiac glycosides that interfere with the nervous systems of vertebrates. The red milkweed beetle manages this by cutting into the leaf's midrib or a stem vein before it feeds, releasing the latex pressure upstream of where it will eat. The latex bleeds out, the pressure drops, and the beetle feeds on tissue that is no longer flooded with sap. This is not a general insect trick. It is a specific behavior, and it is one reason this beetle can live on a plant that many others cannot. The cardiac glycosides the beetle does ingest accumulate in its body and make it unpalatable to most predators. The red and black coloration is a signal that birds and other predators learn to associate with a bad experience. It is the same warning system used by monarch butterflies, which feed on the same plant for the same reason.The milkweed patch itself is a dense community this time of year. Western honey bees, which are invasive here, work the flowers heavily alongside native bumblebees and smaller native bees, all drawn by the nectar. Milkweed flowers have a specific structure: pollen is packaged in small clip-like masses called pollinia, which attach to the legs of visiting insects and are transferred to the next flower. It is an exacting mechanism, and insects sometimes become temporarily trapped in the flower's grooves while the pollinia attach. Larger insects pull free; smaller ones sometimes do not. The red milkweed beetle, which feeds on the flowers rather than gathering nectar efficiently, moves pollen incidentally as it walks. It is not the plant's primary pollinator, but it is present at every flower it eats.

More about common milkweed

July 1, 2026

Summer heat has stalled over the watershed, and ozone is spiking hard — the air quality index jumped from a clean 41 this morning to 92 by afternoon, with forecasts climbing further tomorrow. Right now, is at peak bloom across the region — exactly when it matters most to monarchs.Ozone degrades the volatile compounds that milkweed releases to attract migrating monarchs. The timing is cruel: the plant is doing what it evolved to do, but the chemical signals it sends are being scrambled by the same heat and stagnant air that brought the ozone spike. Monarchs arriving now will have a harder time finding this crucial nectar source at the moment they need it most. The margin between survival and loss in their migration depends on finding these plants — and clean air plays an invisible, essential role in making that possible.

Monarchs laying eggs on midsummer milkweed

June 30, 2026

Along the open edges of Sandy Creek Park, where the tree canopy gives way to sun and the ground stays dry enough for forbs to take hold, common milkweed grows in loose stands. The broad, paired leaves are fully out now, thick and waxy, and the pink-purple flower clusters are either open or just finishing. This is the plant a female monarch is looking for.