Handbook of Nature-Study · Lesson LXXIV · Topic 9: Butterflies and moths
74. The promethea moth
Goal: Your child can find a promethea cocoon hidden in a hanging leaf in winter, and tell the male moth from the female.
You'll need
- A winter walk among lilac, wild cherry or ash
- A screened box kept outdoors in shade (optional, for one cocoon)
- Paints or colored pencils
- A nature notebook and a pencil (colored pencils if you have them)
What's in the book
Comstock's story of the promethea, the most common of our giant silkworms: its caterpillars on wild cherry, lilac, ash and sassafras, its cocoon wrapped in a leaf whose stem is tied to the twig with silk, and its very different father and mother moths. Then Lesson LXXIV with questions on the cocoon, the moth and the caterpillar.
The lesson, step by step
When and where
Late fall and winter. Comstock's method: begin "when the children bring in these cocoons which they find dangling on the lilac bushes or wild cherry trees." Look for single dead leaves hanging straight down from bare twigs that don't let go when the wind blows.
A change from the book
Comstock asks children to tear off the leaf and cut open a cocoon. We leave the cocoon whole, so the moth can come out. If you bring one home, keep it on its twig outdoors in a screened box in the shade, and let the moths go in late spring.
Keep the big idea in mind
Comstock's "leading thought" is the one idea the lesson is meant to lead to. Read it to yourself now, and save it to share at the end, after your child has looked and answered:
The promethea caterpillar fastens a leaf to a twig with silk and then makes its cocoon within this leaf. The male and female moths are very different in appearance.
A clever disguise
On what tree did you find it? Does it look like a cocoon? Does it not look like a dried leaf still clinging to the tree? Do you think that this disguise keeps the birds from attacking it?
How is the leaf fastened to the twig? Could you pull it off readily? What fastened the leaf to the twig?
Look at the leaf stem with the hand lens if you have one: it is wrapped in silk.
Two kinds of moths
Use the book's pictures, or your own moths in spring.
Are there two kinds of moths that come from the promethea cocoons? Does one of them look something like the cecropia? This is the mother promethea.
Are any of the moths almost black in color with wings bordered with gray and with graceful prolonged tips to the front wings? This is the father moth.
Put it into words
Ask your child to explain why the caterpillar ties its leaf to the twig before it spins. Then read the leading thought aloud.
Nature notebook
Comstock's own notebook task:
Make water color drawings of promethea moths, male and female.
Add the hanging leaf with its silk-wrapped stem.