Butterflies and Moths

Splitting its skin

After the caterpillar of the

swallowtail butterfly finds

a place to pupate, or turn

into a pupa, it holds on with

its hind legs and spins a silken

thread. This strong thread

supports the caterpillar while

it waits a few hours for its final

skin to split.

New skin,

old skin

The caterpillar has

to wriggle around to

slip out of its old skin.

As the new pupa skin

forms, the caterpillar

skin falls down to

the bottom.

Final form

The pupa of the swallowtail

butterfly can be either green or

brown to match its surroundings.

This one looks like a green leaf

attached to a twig. Turn to the

next page to see a butterfly

hatch from its pupa.

The caterpillar shrinks and

tightens up as the pupa begins

to form under its skin.

Once the pupa

skin hits the

air, it starts

to harden.

Back legs

grip the twig.

Empty

caterpillar

skin

Can you see the wings?

They are developing

inside the pupa.

The silken thread,

called a girdle,

wraps around the

caterpillar’s body.

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