Pollinator Family Feature: Monarch and Mimic

By Kelle Hartman, Children & Family Educator

You spot a flash of orange and black flitting through your yard and instantly think Monarch! But is it really?

The Monarch butterfly is perhaps the most well-known butterfly that’s seen in Wisconsin. Their bright orange colors are easily recognized even by young children and their caterpillars can be found practically anywhere that common milkweed grows. The ease with which they can be found and raised has made Monarch caterpillars and butterflies a simple and fun science project for many families and adults during the summer.

Monarch PC Constance Gleason

Monarch PC: Constance Gleason

While Monarch caterpillars feast on milkweed only, did you know that the sap of milkweed plants is slightly toxic? It’s true! The caterpillars aren’t harmed while eating it, but the toxin stays in their bodies making them poisonous to predators, especially birds. The animals become sick and learn never to eat monarch caterpillars again. This toxin also stays in the caterpillar’s body through the process of metamorphosis and into adulthood. The bright, bold and orange color of a Monarch butterfly’s wings is actually a warning to predators – DON’T EAT ME, I’M DEADLY!

Monarch caterpillar on black glove

Monarch caterpillar

Commonly mistaken as a Monarch, the Viceroy is another butterfly typically found in Wisconsin. This species is a mimic, meaning it looks nearly identical to Monarchs, “mimicking” or copying their appearance.

It was once thought that the Viceroy developed this clever disguise to fool predators into thinking it was a poisonous Monarch, saving them from becoming lunch. Recent research has shown that predators also avoid them because of the butterfly’s bitter taste, which comes from a chemical in the willow, poplar and cottonwood leaves the caterpillars eat.

Viceroy PC wisconsinbutterflies.org

Viceroy PC: wisconsinbutterflies.org

Viceroy caterpillars also taste bad but they can protect themselves with camouflage. When sitting on a leaf, the caterpillars look just like bird droppings, hiding them in plain sight! These caterpillars also hibernate during the winter, camouflaging themselves to look like dead sticks. As leaves are beginning to drop in the fall, they use silk to attach a leaf to the tree branch. After eating most of the leaf, they leave just enough to wrap around themselves, creating a tube-like shelter for the winter.

viceroy caterpillar on leaf

Viceroy caterpillar PC: Whitney Cranshaw, Colorado State University, Bugwood.org, CC BY-NC 3.0

It’s now believed that both species – Monarch and Viceroy – benefit from looking like the other – predators recognize their bright colors as a warning and avoid eating both types of butterflies!

So, back to that orange butterfly you’ve spotted. How do you tell whether it’s a Monarch or Viceroy? While very similar, there are a few subtle differences in their wing patterns. The easiest pattern to spot is the noticeable black line running through the orange patches on the Viceroy’s hind wings, which the Monarch does not have.

Want to see Monarchs or Viceroys in action? Join us for Butterflies & Blooms this summer to see these two beautiful insects and to practice your identification skills. The exhibit starts Saturday, June 1 and is open daily from 10 am-5 pm through August 31.

Hope to see more Monarchs or Viceroys in your own backyard? Join the Million Pollinator Garden Challenge and plant your own pollinator paradise with these simple garden designs. You can buy some of these plants at Garden Fair, too!

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