It's June and Monarch butterflies are arriving in the northwoods. Raising Monarch butterflies from eggs or larvae (caterpillars) is a fun activity to share with your grandkids, kids, or just for your own enjoyment.
To raise Monarch butterflies you will need:
Butterfly egg or caterpillar
Food for caterpillar
Cage or bug box for caterpillar
You have to start the story with the egg. The ONLY place to find Monarch eggs or caterpillars is on a milkweed plant. THERE ARE NO MONARCHS WITHOUT MILKWEED. It is the only food they eat. There are several types of milkweed growing in Natural Lakes (NL), but the easiest to find is Common Milkweed.
Common Milkweed grows on NL roadsides starting late June. A large patch is near the intersection of Bald Eagle and Coyote, or on Bear Trail along the Duck Habitat I. If you have milkweed on your property PLEASE don't mow it. Besides being the only food Monarch caterpillars eat, it serves as a nectar plant for several species of bees, wasps, butterflies, and other flying insects. Besides, it smells great!
Monarch eggs can usually be found on the tender, common, small leaves at the top of the milkweed plant. The female lays eggs on either the top or bottom of these leaves. The eggs are white and about the size of a grain of sand. Don't touch the egg itself. Simply pick the leaf and put in a small jar with a lid. You can then transfer the caterpillar to the cage or bug box in four to five days after the caterpillar hatches.
You can find caterpillars of different sizes all over a milkweed plant. When picking leaves for your caterpillar, make sure you are not feeding them leaves with Monarch eggs on them because they will eat the leaves AND the eggs.
Remember you will need LOTS of milkweed leaves to feed hungry caterpillars. Clip a stem of leaves (with no eggs on them), wrap the cut end in a wet paper towel, and wrap the end in plastic or in a small jar with water. This will keep the leaves fresh until the caterpillars eat them all. You will need to replace leaves almost every day.
Speaking of eating, Monarch caterpillars have a voracious appetite. After hatching (approx 2-3 days), the caterpillar will eat so much milkweed that will split its skin four times as it grows 3000 times its birthweight. The time period from egg to full grown caterpillar is approximately two weeks.
With all that eating, there certainly is pee and poop. When you change leaves, open your box, remove the leaves WITH the caterpillars attached. It's better not to handle the caterpillars. Rinse out the poop and pee, add new leaves. Tear off a small portion of the old leaf containing the caterpillar and set it on the new leaves and close the box.
The Chrysalis Stage
The chrysalis stage is why it's important to have a large ventilated enclosure with a strong lid. For the last 30+ years I've used a cage from a pet store. They are readily available on Amazon (click here for Amazon link). The cage's ventilation is small enough to prevent a caterpillars over four days old from escaping. The top provides the sturdy support necessary for the larvae to undergo the spectacular metamorphosis from caterpillar to chrysalis to adult butterfly. This entire process takes about four weeks.
When the caterpillar has reached its maximum size, it will crawl to the top of the cage a spin a silk button under the top of the cage and hang there for hours. If you're lucky you will catch the few moments when the skin falls away and the beautiful green chrysalis is revealed. In about ten days you will see a perfectly formed butterfly within the now clear chrysalis. It takes less than a minute for the chubby, short winged butterfly to emerge. It takes several hours for the butterfly to pump its crumpled wings with fluid allowing them to dry out, enlarge and stiffen. For this entire time the new butterfly is hanging from what remains of the chrysalis. This is why you need a safe container with lots of space for the butterfly to have room to hang and fully extend its wings. It's important to not disturb or touch the butterfly for at least four hours.
Releasing your Butterfly
When the butterfly is dry and stretching its wings it's time to release it on a nearby flower. Carefully open your box and the butterfly will often crawl on your finger to be released. Set them on a flower and watch them some more. This is a great time for pictures because the butterfly will often rest more on the flower before flying away.
Monarch butterflies winter in Mexico. It takes four to five generations to make the roundtrip from Mexico to Wisconsin and back to Mexico. There are two generations of Monarchs you will see in NL. The first generation arrives from the southern US in June. The Monarchs arriving in NL in June will breed and the next generation of Monarchs emerging from in late August/September will the ones migrating thousands of miles to Mexico.
If you are curious the sites below are excellent sources for Monarch and butterfly information. Enjoy your butterfly experience, share this exciting process and education with your family. And remember DON'T MOW THAT MILKWEED!!
Monarch Watch https://monarchwatch.org/
Biology of the Monarch Butterfly https://www.emporia.edu/ksn/v62n2-november/index.html
The Xerxes Society https://xerces.org/butterfly-conservation/