Handbook of Nature-Study · Lesson LXX · Topic 9: Butterflies and moths
70. The black swallowtail butterfly
Goal: Your child can describe the black swallowtail caterpillar and how it defends itself, and follow it through chrysalis to butterfly.
You'll need
- Garden parsley, dill, fennel or carrot plants to search
- A large clear jar or mesh box with a lid of netting, and fresh leaves of the same plant
- A blade of grass
- A hand lens (magnifying glass)
- A nature notebook and a pencil (colored pencils if you have them)
What's in the book
Insect Study opens with Comstock's introduction to how insects grow: eggs, larvae, molting, pupae and adults. Then her story of the black swallowtail and Lesson LXX, with a leading thought, method, ten questions on the caterpillar and chrysalis and three on the butterfly, and a child's memory of the "caraway worms".
The lesson, step by step
When and where
Mid to late summer, into September. Search garden parsley, dill, fennel or carrot tops for a fat green caterpillar banded with black and spotted with yellow. Comstock's method: bring in a plant with these caterpillars, give them fresh food day by day, and let the children watch.
Safety first
Use garden plants only. Some wild plants of the carrot family, such as poison hemlock and wild parsnip, are poisonous or burn the skin. Wash hands with soap and water afterward.
If you keep a caterpillar, give it fresh leaves every day, keep the jar out of direct sun, and let the butterfly go outdoors on the day it comes out.
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 caterpillars of the swallow-tail butterflies have scent organs near the head which they thrust forth when attacked, thus giving off a disagreeable odor which is nauseating to birds.
The surprise horns
Find a caterpillar on its plant.
Touch the caterpillar on the head with a bit of grass. What does it do? What color are the horns? Where do they come from? Are there two separate horns or two branches of one horn? What odor comes from these horns? How does this protect the caterpillar?
The forked orange horns pop out and smell bad, then slip back in.
A good look
What is its ground color? How is it striped? How many black stripes? How many yellow spots in each black stripe?
Observe the caterpillar eating a leaf. How does it manage so as not to waste any?
The chrysalis
If you keep a caterpillar, watch daily when it stops eating and wanders.
When a caterpillar is full grown, how does it hang itself up to change to a chrysalis? How does it make the silk button? How does it weave the loop or halter?
Describe the chrysalis. What is its general shape? What is its color? Is it easily seen?
The butterfly
When the butterfly comes out, or in the garden on a sunny day:
Why is this butterfly called the black swallow-tail? What is the ground color of the wings? How many rows of yellow spots on the front wings?
Watch the butterfly getting nectar from the petunia blossom and describe the tongue. Where is the tongue when not in use?
Then ask your child how the caterpillar protects itself, and read the leading thought aloud.
Nature notebook
Draw the life story in a circle: egg, small caterpillar, big caterpillar with horns out, chrysalis with its silk loop, butterfly with its "swallow-tails". Date each stage you saw.
Tip
The horns have a name: an osmeterium. Children love the word, and the smell is harmless.