Monarch Butterflies Return To Wisconsin

Map of Monarch butterfly spring and
summer migration

Wisconsin is in the core breeding ground for the eastern migratory population of monarchs.

Wisconsin's milkweed feeds and produces several generations of the iconic black and orange beauties each spring and summer before a final wave gorges itself on wildflower nectar and embarks on a 1,700-mile journey to central Mexico.

These long-distance fliers, the weight of a paper clip, spend their winter resting in fir trees in the mountains before migrating north. They get as far as Texas before laying eggs and dying. Their offspring take up the journey, and it is mostly this generation of butterflies that reaches Wisconsin in the May and lays their eggs, beginning the cycle again.

Monarchs return in May — milkweed is the only host plant for Monarch butterfly caterpillars.

Midwestern states, including Wisconsin, once provided more than 85 percent of monarch butterflies in the eastern migratory population. The introduction of herbicide-tolerant corn and soybeans and the accompanying increase in herbicide use in the 1990s inadvertently led to steep losses as milkweed disappeared from between rows of corn and soybeans.

Now the new generation of Monarchs will begin their multi-generational migration northward. These shorter-lived Monarchs have a two to six-week lifespan and travel only part of the way to their destination. The first generation of the shorter-living Monarchs only make it as far as the southern U.S. During this leg of the journey, the butterflies lay as many eggs as possible: one adult may lay up to 100 eggs.

It takes three generations to reach their breeding grounds in the northern U.S. On their journey, they lay their eggs exclusively on milkweed and then perish. Each subsequent generation continues north, the cycle repeating until the Monarchs reach their destination.

Monarch Butterfly, Danaus plexippus, Caterpillar

Monarch Butterfly Fun Facts

The male monarch has two dots near the back of its wings, which distinguish it from a female.

A female that is ready to mate will land next to a male on the ground. If the male is interested, he will scoop up the female and they will fly together into a tree or other vegetation to mate.

It takes about a month to metamorphose from egg to caterpillar to chrysalis (a caterpillar with a self-produced veneer type coating) to butterfly.

Three newly hatched caterpillars will fit on a grain of rice, but as they eat milkweed, they grow to 1,000 times their initial size in two weeks.

In fall, monarchs fly from Wisconsin to Mexico, taking about a month to fly up to 1,500 miles. They spend the winter in the mountain forests of central Mexico, and their children fly north in the spring.

These species are native to the Midwest, easy to grow, versatile in their habitat preferences, attractive, and have a variety of colors and blooming times. Many of the showiest species on the list are "late blooming" species, which are especially important for monarchs. Late summer is when they are fueling up on nectar for their long migration to Mexico. These species will also attract a variety of other butterflies and pollinators.

Monarch Butterfly, Danaus plexippus, Adult

Anise Hyssop (Agastache foeniculum)
Crooked-Stem Aster (Symphyotrichum prenanthoides)
Butterflyweed (Asclepias tuberosa)
Common Milkweed (Asclepias syriaca)
Meadow Blazingstar (Liatris ligulistylis)
New England Aster (Symphyotrichum novae-angliae)
Orange Coneflower (Rudbeckia fulgida)
Downy Phlox (Phlox pilosa)
Purple Coneflower (Echinacea purpurea)
Swamp Milkweed (Asclepias incarnata)
Showy Goldenrod (Solidago speciosa)
Black-eyed Susan (Rudbeckia hirta)