Handbook of Nature-Study · Lesson LXXVIII · Topic 10: Insects that live in leaves
78. The leaf-rollers
Goal: Your child can find rolled leaves, show how silk ropes hold them, and explain why the caterpillar lives inside.
You'll need
- Rolled or tied leaves from shrubs and trees (staghorn sumac, basswood, witch-hazel and many others)
- A hand lens (magnifying glass)
- A soft paintbrush
- A nature notebook and a pencil (colored pencils if you have them)
What's in the book
Comstock's story of leaf-rollers: sumac leaflets rolled into little cornucopias, basswood leaves cut and rolled, the witch-hazel as "a veritable insect tenement", and silk cables fastened like tent ropes. Then Lesson LXXVIII's leading thought, method and nine questions.
The lesson, step by step
When and where
Early autumn, and July or early August to find caterpillars still inside. Comstock: "The rolls are found plentifully on sumac, basswood and witch-hazel."
Safety first
Comstock's sumac is the harmless staghorn or smooth sumac of dry, sunny roadsides, with fuzzy red berry clusters standing up. Poison sumac is different: it grows in wet, swampy places and has drooping clusters of whitish berries. Learn to tell them apart before you go, and if you are not sure, don't touch. Before you go, learn to recognize poison ivy ("leaves of three, let it be"), and poison oak or poison sumac where they grow. We never eat any wild berry, leaf or plant.
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:
There are many kinds of insects which roll the leaves of trees and plants into tents, in which they dwell and feed during their early stages.
How is it made?
What is the name of the trees and shrubs from which these rolled leaves which you have collected were taken?
Is the leaf rolled crosswise or lengthwise? How large is the tube thus made?
How is the roll made fast? Examine the little silken ropes with a lens and describe one of them. Is it wider where it is attached to the leaf than at the middle? Why?
Unroll it
Unroll one leaf slowly.
As you unroll the leaves what do you see at the center? Has the leaf been eaten? Can you discover the reason why the caterpillar made this roll?
Watch one roll a leaf
In summer, try Comstock's question 9:
In July or early August get some of the rolls with the caterpillars in them, unroll a nest, take the caterpillar out and put it on a fresh leaf of the same kind of tree or shrub on which you found it, and watch it make its roll.
Move the caterpillar with the soft paintbrush, and put the leaf back on the same plant afterward.
Nature notebook
Draw a rolled leaf with its silk "tent ropes" drawn in, and a close-up of one rope under the lens. Then read the leading thought aloud and add it as a caption in your child's own words.