You’ve probably heard of monarch butterflies, but have you ever seen one before it becomes a butterfly?
In late August, park staff and a few volunteers were lucky enough to find a monarch caterpillar while working in the Buttrick Garden. The caterpillar was well over an inch long, so had clearly been around for a little while! This caterpillar was growing on and eating a milkweed plant. Milkweed and monarchs go hand in hand- milkweed is the sole host plant for monarchs, which they need for development and survival.
A female monarch butterfly will lay an egg on a milkweed leaf earlier in the season. When the egg hatches into a tiny caterpillar, it starts eating the leaves of the milkweed. Over time, it grows to the chunky size we saw in late August! If you’ve ever accidentally broken the leaf of a milkweed plant, you may have seen some white milky-looking sap come out. That sap, and milkweed plants generally, contains compounds that are toxic to most birds and mammals, but not to monarchs! By eating milkweed, the caterpillars and then the butterflies are toxic to most predators.
Milkweed, of which there are multiple species, is an incredibly important native plant not only for the survival of monarchs, but also as a great pollinator plant for many creatures. Not to mention the blooms in mid-summer are stunning! Next year, consider encouraging milkweed growth in your gardens and wild spaces near you to help native wildlife.
Article and photo by Rachel Vincent, Biologist at Minute Man National Historical Park.
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