The Original Transformer: Life Cycle of the Monarch

As the warm summer days grow shorter and the leaves begin to turn, instinct prompts the Monarchs to look towards southern lands. Soon they will begin their perilous journey south, traveling all the way to Mexico one tiny wing beat at a time.

Over the past weeks Ottawa National Wildlife Refuge provided food and shelter to these insects as they transitioned from egg to caterpillar to chrysalis, and finally adult butterfly. So before these charismatic insects depart, let’s take a moment to reflect on how far they’ve already come.

(Photo by Ryan Hagerty, USFWS)

It all starts with a tiny egg. Only a few millimeters long and laid by itself on the underside of a leaf, this egg is well hidden from predatory eyes.

This caterpillar is as big as they come. Soon, it will curl into a J-shape and form its chrysalis. (Photo by C. Verdu)

After four days, a caterpillar much smaller than this one crawls out. Its goal is simple:  eat milkweed. It will devour the plant until it is too big for its skin.

Then it molts, like a Thanksgiving dinner guest exchanging formal attire for sweatpants so that she may eat some more.

Each Monarch caterpillar will transition through five different body sizes, called instars. Finally, when they are as large as the caterpillar above, they are ready to leave their wingless life behind.

Our Visitor Center housed a few Monarchs as they transitioned from  (Photo by C. Verdu)

At this point, the caterpillar hangs upside down and forms a chrysalis. Like the caterpillar and the adult butterfly, the Monarch’s chrysalis has a striking appearance. Jade green with a gold bar, it’s well camouflaged in a garden. Once the chrysalis forms, the adult butterfly will emerge in about ten days.

This Monarch spent its first moments as an adult drying its wings in the safety of our pollinator garden.  (Photo by C. Verdu)

Eventually, an adult butterfly will emerge. It spends its first moments carefully flapping its wings to dry them out.

(Photo by C. Verdu)

Finally the adult butterfly is ready to take flight. In its mature form it is not restricted to eating milkweed and will visit a wide variety of nectar-laden flowers. Soon, these butterflies will leave the Midwest in search of warmer winter climates.