Monarchs & Milkweed

Submitted by Ralph Grathoff, Chairman, Natural Resources Commission

Consider the not so humble Monarch butterfly “king of the butterflies.” This lucky little bug begins its life cycle in our area and then travels to Mexico for the winter, leaving behind an envious naturalist-inclined resident to ponder the wisdom of living in an area where weather forecasts often include the words: polar vortex.

The Danaus plexippus, or milkweed butterfly, whose trajectory of evolution has led its life cycle–egg, larvae, pupa/chrysalis, adult–to require a dependence on a single species of plant. A plant with weed built right in its common name. There are 20 or so species in the milkweed family Asclepiadaceae in Illinois. Common milkweed Asclepius syriaca is the one most prevalent in our area. It is the destruction of this “weed” in the monarch’s case, and the overall destruction of habitat for pollinators in general, that has contributed to a large decline in monarch populations over-wintering in much warmer climes and an alarming reduction in pollinating insects overall.

Photo: Chuck Heidgen

It’s endlessly fascinating, that a relationship between a “weed” in Illinois and a seemingly fragile butterfly, again this little insect manages to hoof it thousands of miles in its migration, can be so dependent on the preservation of the weeds’ habitat.

Photo: Chuck Heidgen

So, go ahead and leave the milkweed to grow in the garden and encourage the preservation of open spaces. You might get lucky and catch a glimpse of a really large caterpillar and a butterfly floating around the garden on a warm July day. Something to remember when as soon enough the weather forecast will flash “wind chill warning.”