A Conversation About Monarchs

Monarch time! Yup, we’re starting to see Monarch butterflies and their caterpillars and witnessing the beginning of the great migration. It’s the culmination of a process that’s been developing for millennia. Monarchs have enjoyed massive publicity and other attention over the past decade or so, and with good reason. They’re the poster child for restoring the native environment, as people have come to understand our interconnection with the rest of the inhabitants of the planet. Pretty much everybody recognizes a Monarch when they see one, and has heard about their reliance on the milkweed plant.  Schoolchildren conduct science experiments and observe new butterflies as they emerge from their pupal stage.  I have a friend who went on the trek to a “secret” place in Mexico where tens of thousands of Monarchs migrate to winter over before beginning the next leg of the round trip and heading north for their summer. Nature Calls, Conversations from the Hudson Valley, episode 57, has a conversation with Devon Russ and her travel partner, and it’s fascinating. I learned so much about the efforts of people across the continent to provide a highway of sorts for the insects to safely make their trip, including how the plants they require vary by region. And I’m amazed by the fact that several generations are required to make the total journey.              So I wanted to refresh my knowledge of the connection between the plant and the insect. There’s a scheduling that has been built into the genes of both, so what each one needs from the other is provided just when it needs it, That’s pretty remarkable, and is the subject of study in the science called phenology. Episode 21 of the podcast discusses phenology in depth, and I learned how deeply the various plant and animal species depend on each other. With the Monarch and the milkweed, each of the partners benefits the other at the various stages of life. Monarchs are a major pollinator of milkweed, and the milkweed repays the favor handsomely. Monarchs acquire a chemical by feeding on the milkweed that makes it toxic to predators, and lays its eggs on the leaves of the plant. When they hatch, the larva then feed on the leaves throughout their four molt stages. Once they’re big enough, the caterpillars usually leave the plant and find a place to attach and begin to build their chrysalis. After ten to fourteen days, the butterfly emerges and begins the next life cycle.                                                                   There are a few things we should all know if we want to join the army of Monarch admirers. There are many kinds of milkweed, and there are preferred choices for our region. The swamp milkweed and the common milkweed are not only the easiest to find in the wild, but the best choice for us in upstate. The seeds are easy to collect from their pods when they ripen in the fall… it’s that silky stuff. And they’re easy to find in the wild.                                                                                                                                              The focus is usually on the butterfly, but you might find a closer look at the milkweed plant interesting. Start with the scads of insects that interact with common milkweed (Asclepias spp). There are at least two moths, one of which is as dependent on the milkweed as the Monarch; many butterflies, flies and beetles are pollinators and some eat the leaves and seeds as well. There are some predators that feed off the other insects, and there is a really neat little guy called the large milkweed bug. It’s orange, like the Monarch and for the same reason. It absorbs a toxin from the plant and the color is a warning sign to predators. These are fun to watch. They make swarms of various sizes and live stages (instars), and feed on the seed of the milkweed.                                                                                                                          While the butterfly is a wonderful thing to encourage, remember its host to encourage the whole cycle. One of my favorite things about the milkweed is one you may not know about. If you see a milkweed in flower, go say hello. The scent is like honey in an aerosol form and it drifts through the air like an invisible ribbon. Having said all that, I must put in a word for common sense. It is good to encourage milkweed, but it’s not murder to remove them when they pop up uninvited.