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Published 05 Aug, 2017 07:18am

Facts: Caterpillars

A caterpillar has just one job — to eat

During the larval stage, the caterpillar must consume enough to sustain itself through its pupal stage and into adulthood. Without proper nutrition, it may not have the energy to complete its metamorphosis. Malnourished caterpillars may reach adulthood, but be unable to produce eggs.

A caterpillar’s first meal is usually its eggshell

In most cases, when a caterpillar hatches from its egg, it will consume the remainder of the shell. The outer layer of the egg, called the chorion, is rich in protein, and provides the new larva with a nutritious start.

Caterpillars produce silk

Using modified salivary glands along the sides of their mouth, caterpillars can produce silk as needed. Some caterpillars, like gypsy moths, disperse by ‘ballooning’ from the treetops on a silken thread. Others, such as eastern tent caterpillars or webworms, construct silk tents in which they live communally. Bagworms use silk to join dead foliage together into a shelter. Caterpillars also use silk when they pupate, either to suspend a chrysalis or to construct a cocoon.

Self-defence and caterpillars!

Caterpillars employ all kinds of strategies to avoid becoming a bird snack. Some caterpillars look like bird droppings. Certain inchworms in the family Geometridae mimic twigs, and bear markings that resemble leaf scars or bark.

Other caterpillars use the opposite strategy, making themselves visible with bright colours to advertise their toxicity. A few caterpillars, like the spicebush swallowtail, display large eyespots to deter birds from eating them.

Published in Dawn, Young World August 5th, 2017

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