Milkweeds for Monarchs
by Kevin Luby, Naturalist, Willowbrook Wildlife Center
In October, second- and third-grade classes from Ben Franklin Elementary School in Glen Ellyn visited Willowbrook Wildlife Center in Glen Ellyn for one of the center’s problem-based learning programs, which get students to think about current environmental issues and create logical and logistically feasible solutions. This particular program focused on the role milkweed plants play in the lives of monarch butterflies and why scientists think that populations of both have been declining over the past two decades.
Monarchs are by far the most recognized butterflies in DuPage County if not the world, and like other insects, they develop in stages. For monarchs, the road from eggs to larvae to pupae to adults can take five to six weeks.
As adults, monarchs use their long needlelike proboscises to suck nutritious nectar from a wide range of flowers, a technique that also makes them pollinators, but as larvae, or caterpillars, they eat only one thing: milkweed. In fact monarchs cannot make it past the larval stage without the plant. (The upside to evolving into such picky eaters is that milkweeds are poisonous to birds and other hungry animals, which makes monarchs poisonous as well, and unappetizing to predators.)
In addition to this specialized diet, monarchs are fascinating because they’re the only North American butterflies that fly south for the winter — up to 1,500 miles south. Adults that emerge in DuPage in spring and summer live just two to five weeks, but those that hatch in late summer or early fall can live seven to nine months, enough time to make the trip to Mexico and most, if not all, of the journey back north in the spring.
But researchers believe that illegal logging in the high-altitude forests that monarchs seek out in winter and improper pesticide and herbicide use in summertime breeding areas that they rely on in the States are knocking back monarchs and the plants that these insects cannot live without.
To help counter some of these ills, for over a decade Willowbrook Wildlife Center
has been building a butterfly booster program. In 2002 it installed a butterfly garden to showcase practical, aesthetic landscape ideas that visitors could use to attract native and migrant butterflies and other species to their own backyards. In 2010 it added multiple flats of common, Sullivant’s, butterfly, swamp and whorled milkweeds specifically to benefit monarchs and started collecting and spreading seeds from the plants throughout the surrounding forest preserve. In 2012 these efforts earned the center’s garden and the 40 acres behind the visitor center designation as a Monarch Waystation through the national Monarch Watch
program, which requires participants to provide perennial and annual nectar-producing plants as well as shelter and proper management.
The Forest Preserve District as a whole is working on an even larger scale. Countywide, milkweed grows on about 30 percent of the nearly 26,000 acres of forest preserve land, but with challenges in so many corners of the monarch’s world, the District is bumping up its percentages. Since 2010, habitat restoration projects at 11 different forest preserves have used more than 50 mixes of native seeds that have included milkweeds. Volunteers collected some of the seeds by hand from many of the nine species that grow in the forest preserves themselves. At West Branch Forest Preserve
in Bartlett alone, crews have spread one ounce of seeds per acre on over 250 acres each year since 2013. That’s 1.6 million seeds!
After hearing all of the facts, the students from Ben Franklin decided to put their heads together to come up with a way they, too, could help these beautiful butterflies. They ended up approaching the Glen Ellyn
village board to suggest that their hometown be more monarch friendly. Since they knew that monarchs depend on milkweeds, they proposed that the village plant milkweeds where it would normally grow other species. Glen Ellyn’s environmental commission listened intently and agreed to help Illinois’ state insect.
An interagency task force formed to raise awareness and help residents understand the plight of these important pollinators. In March, the Glen Ellyn Public Library
and Willowbrook Wildlife Center teamed up to present two public programs that explained not only why monarch populations were declining but also how people could grow milkweed in their own gardens. Over 200 enthusiastic citizens attended, all eager to do their part to create a premier monarch oasis in the western suburbs with milkweeds added to 100 public and private gardens. And it’s all thanks to the efforts of a few school children who saw a need and had the courage and foresight to stand up and say something about it.
Although monarch caterpillars rely solely on milkweeds, blazing star and other native flowers provide a great source of food for adults.
Even developing monarchs have distinctive markings that help hungry predators identify — and avoid — these poisonous caterpillars. © Brett Whaley
The butterfly garden at Willowbrook Wildlife Center offers ideas to help you be monarch-friendly at home.