Milkweed-it’s not just for monarchs

Monarchs have been few and far between this season in my neck of the prairie. But the milkweed has literally been booming everywhere including in my perennial gardens. I decided to leave well enough alone in anticipation of the Monarchs perhaps just being a little late to the party. And in fact, a few are making an appearance as I write this article. But in the many weeks that I’d been observing the milkweeds looking for those little tiny pearl Monarch eggs, I began to notice how many other insects favor the Milkweed plant. So I dug in and did some research on this “weed” and was surprised at how important it is to the insect world beyond Monarchs.

Though milkweed is an important food source for Monarchs, it’s not the only one they are dependent on. However, it is the only plant that the Monarch caterpillar has as a food source. Monarchs, like many species of insects, have evolved to specialize in their larval stage (in this case caterpillar) for a specific food source in order to gain protection from predators through the chemicals they ingest from the plants they eat. Milkweeds contain cardiac glycosides, which are toxic to many species of birds and mammals. It’s not fool proof however, as some insects have evolved to be somewhat resistant to those toxins.

But the milkweed flower nectar is a food source for many other insects. I’ve seen Eastern Swallowtails, Bumble Bees, Skippers, and others feeding on the flowers. What I’ve also seen is lots and lots of ants and aphids. The ants feed on the honeydew left by the aphids and the aphids rarely do any serious damage to the plant but are a valuable food source for other insects. If you find a milkweed plant that looks like the leaves have been chewed down to the leaf stem, it’s probably a Milkweed Tussock Moth Caterpillar. They literally skeletonize the plant.

And all that fluff attached to the Milkweed seeds makes wonderful nesting material for the birds. The fibers of the fluff are so strong that even Baltimore Orioles use it for their large sagging nests that often are made way out on the end of a tree branch. Imagine how comfy that nest is with all that soft fluff. But with all this information on the Common Milkweed let’s not forget about the Swamp Milkweed which is another food source and laying sight for the Monarch butterfly. I’ve found many Monarch eggs on Swamp Milkweed over the years so, if you live near a low land or wetland, look for this plant and you’ll see Monarchs.

I was really concerned about the lack of Monarchs for most of late June and early July, but it seems that what I may be seeing now are the next generation from those brave Monarchs that flew from Mexico, laid eggs that created a new generation that finally found their way to central Minnesota. So glad they’re back and so glad I am able to grow the habit they need as well as others in the insect world.