If you’ve never seen a monarch caterpillar hatch, you’re certainly not alone. The eggs are about the size of the tip of a pencil. Yet a lot is going on inside!
Below is video taken (with a microscope attachment) as a baby caterpillar breaks out of its egg. It then eats the egg as its first meal.
We named this little guy Miles—inspired by the many miles monarchs travel on their trip to Mexico.
Miles’ egg was found on a plant growing next to a concrete parking lot in Sterling, MA. The egg was removed in case the plants were cut down, which they often are in parking lot cases. The shell darkens before hatching. That’s the caterpillar getting ready to break free.
After eating its eggshell, monarch caterpillars rely on milkweed plant leaves for all meals. Milkweeds are the only food for these caterpillars. There are a variety of types of milkweeds. If you order seeds, make sure to get milkweed plants that are native to your area.
Milkweed seeds can be planted in the fall and winter or placed in the fridge to mimic natural cold stratification. There are a number of great ‘how to’ videos to learn more about growing milkweed plants.
Saving milkweed plants
It’s hard to tell how many monarch eggs or baby caterpillars like this are killed each year. They have a variety of predators. Habitat destruction and chemicals are a bigger threat to the species as a whole. The problem: they are often cut down as weeds, cleared for construction, or sprayed with chemicals.
Instead of clearing them or spraying them, consider planting native pollinator plants around them to give adult butterflies a great place to stop. Milkweed plants often have flowers that are pretty and complement other flowers well.
Will a monarch lay eggs if you have a milkweed plant ready? It’s hard to tell as there are dwindling numbers of monarchs, which are endangered. Those who track monarchs say improving habitat is critical.
To create a habitat, avoid spraying the plants with chemicals or cutting them (you could be cutting off eggs or caterpillars; they are small!) and plant milkweed and other native pollinator plants that are protected from spraying or mowing.
The monarch butterfly’s lifecycle is pretty amazing to watch. After hatching, monarch caterpillars go through weeks of rapid growth. They have to literally shed their skin to grow. This includes busting out of their little face masks. This video (still using a microscope camera) shows one of little Miles’ molting sessions.
Many baby caterpillars like Miles won’t make it due to habit loss or spraying. Here are some resources to learn more about how to help:
Check back here in the coming weeks. We’ll post the video of Miles and friends as they continue their journey toward becoming butterflies. We’ll also look at the serious illness that is spreading among monarchs, why it can kill many, and what NOT to do if you see baby caterpillars.