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Cristina Rossi Marco Fragiacomo

THE WORLD OF MOTHS

Istituto Tecnico Agrario Statale “Giovanni Brignoli”Gradisca d’Isonzo

METAMORPHOSIS OF A CECROPIA MOTH

From egg to moth

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What do insects look like? Most insects undergo a transformation of their bodies known as metamorphosis.

The metamorphosis of caterpillar into a moth is a well known biological phenomenon. However, a long ago it was considered one of the most mysterious.

Some experiments have carefully investigated these changes.

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FROM EGG TO PUPA

The following pictures show the process of metamorphosis in the life cycle of a cecropia moth.

• An egg hatches after 10 days (picture 1). The caterpillar has turned green to match the natural environment.

• The caterpillar grows enormously, splitting out of four skins in the process (picture 2).

• Glands near the caterpillar’s mouth (picture 3) extrude liquid silk so that the caterpillar can spin the cocoon.

• The developing pupa without its cocoon (pictures 4, 5

and 6).

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Picture 1

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Picture 2

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Picture 3

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Pictures 4 – 5 – 6

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Picture 7

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FROM PUPA TO MOTH

• The moth escapes from the dry skin of the pupa (picture 7). The skin begins to split at the head and the moth comes out. Then, using its legs, the moth pulls out its body free end exposes its folded wings. Blood expands the wings, so that the moth can fly.

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Two research questions

1. What causes this incredible change of body form and function?

2. What mechanism controls its timing, so that the moth leaves its cocoon only in the warm weather of spring?

Pictures and text from:

Farb P. & The Editors of Life, The Insects – Life Nature History, Time – Life International