Woolly Bear Secrets Revealed

The Secret Life of the Woolly Bear Caterpillar

by Laurence Pringle; illus by Joan Paley

32 pages; ages 5 - 7

Boyds Mills Press, 2014

“Bella is no ordinary caterpillar,” writes Laurence Pringle. “She is a banded woolly bear...” So begins this introduction to the secret life of a well-loved caterpillar.

Bella has 16 legs – how do you even walk on 16 legs? Not to worry – Pringle explains how different legs help Bella climb, move, and even help her eat. And eat. And EAT… woolly bears, it turns out, eat a lot. And produce a lot of frass (a cool word for caterpillar poop).

Bella eats all summer long, and then finds a safe place to sleep away the winter. In the spring, wooly bears wake up and start eating. Again.

Perhaps you’ve seen Bella and her buddies wandering about your yard searching for tender grass and tasty dandelion leaves to nibble. If so, take a few moments to watch them. If you have a glass plate or petri dish, put a woolly bear in it and watch how they walk. If you have a sandy area, put a woolly bear down and see what sort of tracks it makes.

Then help it get to a green and grassy place  because soon, very soon, Bella will spin a cocoon and change into an Isabella Tiger Moth. And then, one day later this summer, she’ll lay her eggs that will hatch into baby woolly bears.

Pringle gives us a great view into the every day life of a common caterpillar, and Joan Paley's bright and bold illustrations are perfect for spring. 

Drop by STEM Friday to see what other science books and resources bloggers are sharing.  Review copy provided by publisher.

Waiting for Wings: life inside a chrysalis

While weeding the onions I discovered this tiny chrysalis. The neighborhood butterfly expert says it’s a Baltimore Checkerspot – a butterfly that has mostly black wings (with some white spots) that are rimmed with orange. I’d seen them flying around, and even caught sight of one of the bristly caterpillars hanging out on plantain – a weed I was pulling from the onion beds.

I want to watch the butterfly emerge, so I taped the onion leaf to a protected area on my porch. Every day I run out to check it, to see if “my checkerspot” has got its wings.

A chrysalis is the “pupa” of the butterfly. The caterpillar (larvae) spins a silk pad on the underside of a leaf – or in this case, an onion leaf shaded by weeds – and then hangs upside down and begins changing form.

What we see on the outside is this: the case that holds the metamorphosing butterfly within. It may look as though it’s resting, but there are a lot of changes going on inside. The caterpillar's tissues break down and completely reorganize.

Groups of cells, called “imaginal disks” give rise to things like wings. Or legs. Even antennae. The dissolving caterpillar provides a nutrient-rich fluid for these cells. They begin growing really fast, differentiating into muscles, heart, nervous system.

All this happens inside the chrysalis – so when the butterfly is finished forming and ready to emerge, there’s a lot of waste products in there too. That’s the reddish-colored liquid that sloshes out after the butterfly emerges.

If you go hunting chrysalides (that’s more than one chrysalis), make sure you check protected spots: the undersides of leaves, shady stems, even the sides of rock walls. You can make a net cage to protect chrysalides from predators, but make sure you’re around to release the adults once they emerge and have dried their wings.