Volunteer Newsletter: Madame’s Butterflies

by Jane Balaban


Got Milkweed? If you do, you likely have noticed the beautiful Monarch butterflies visiting your plants as the females deposit eggs on the milkweed, the host plant for their caterpillars. While any plant in the genus Asclepias will serve as host plant, the Common Milkweed, Asclepias syriaca, can usually be found in alleys, invading yards, and empty lots, if you don’t have milkweeds in your garden.


For a number of reasons, populations of this beloved species have been on the decline for the last two decades. With the increased awareness focused on their possible extinction, a summer project that has engaged many people is raising monarchs from egg to adult and releasing them. It’s a fascinating and fun thing to do, and especially great to get kids involved in. (We know of at least three such projects by North Branchers Steve and Linda, John and Marian, and John and Jane.)


A close inspection of the underside of a milkweed leaf may reveal a tiny cream-colored egg deposited by the female, usually one per leaf. Bring the leaves inside and wait for the miniscule caterpillar to hatch, after which it consumes its shell and starts munching on the leaf. As the cats grow, they need a constant supply of fresh milkweed leaves. For a couple of weeks, they eat and poop and grow, getting to be fat and a couple of inches long.


At some point, triggered by a signal known only to the caterpillar, they begin what might be called their walk-about. They stop eating and start searching for a place to attach to before entering the chrysalis stage. A good object that works well as a support is just a simple spray of plastic leaves.


Once they settle on a stem or leaf underside, they spin a small silk button, attach to it, and hang in a “J” form for a bit. When they’re ready, they shed their caterpillar skin and transform into a beautiful green and gold chrysalis. Life as a chrysalis lasts several weeks, during which there’s a miraculous internal transformation into the adult form.


Just before hatching, the chrysalis becomes transparent and the adult colors are visible. Soon the chrysalis splits along the back and the adult emerges. It hangs on to the old chrysalis for a while, letting its wings dry and harden. When it begins periodically flapping its wings, it signals that it will soon fly. That’s the time to keep a close watch lest it ends up flitting about the house!


Fortunately, at that stage the adult will walk onto your finger so that you can transport it outside. It’s tempting to utter bon voyage as you watch “your” monarch take off, fly a few circles, find a temporary resting spot then fly off! In late summer or early fall, millions of adults, including some of “ours,” will begin the long journey to their over-wintering grounds in Mexico.


Some links to more information about the Monarch:

Visit two of the treasures of the Forest Preserves of Cook County