← Handbook of nature-study for teachers and parents, Volume 1
Chapter 163
Lesson LXXVIII
The Leaf-rollers
Leading thought—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.
Method—This is an excellent lesson for early autumn when the pupils may find many of these rolled leaves, which they may bring to the schoolroom, and which will give material for the lesson. The rolls are found plentifully on sumac, basswood and witch-hazel.
Observations—1. What is the name of the trees and shrubs from which these rolled leaves which you have collected were taken?
2. Are more than one leaf or leaflet used in making the roll?
3. Is the leaf rolled crosswise or lengthwise? How large is the tube thus made?
4. Is the nest in the shape of a tube, or are several leaves fastened together, making a box-shaped nest?
5. 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?
6. How many of these tent ropes are there which make fast the roll? Unroll a leaf carefully and see if you can find signs of the tent ropes that fastened the roll together when it was smaller. Can you find where it began?
7. 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?
8. How do you think a caterpillar manages to roll a leaf so successfully? Where is the spinning gland of a caterpillar? How does the insect act when spinning threads back and forth when rolling the leaf? What sort of insect does the caterpillar which rolls the leaf change into? Do you suppose that the same kind of caterpillars makes the rolls on two different species of trees?
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.
Supplementary reading—“A Dweller in Tents” and “A Little Nomad,” in Ways of the Six-Footed.