Insect behaviour and survival



Like the stick insects we have studied, our caterpillars show amazing behavioural patterns that assist them in surviving their many predators. The many different behaviours are permanently imprinted in the caterpillar’s brain. Although the genes for flight are present in the caterpillar, you will not see the caterpillar jumping from the branches of trees trying to fly. All these behaviours come into play at crucial times during the insect’s development, as a result of hormonal changes. Different hormones or different levels of hormones turn certain behaviours on or off.

The Masters of Deception video is a very important resource for answering the questions below.

Answer the following questions through careful observation.

1) During the brown stage, as shown on the right, describe whereabouts on the tree does the caterpillar rest? Explain why


2) During the green stage where does the caterpillar mainly rest? Is there a reason?



3) How does the caterpillar respond to being touched?


4) Describe the feeding pattern
- Does the caterpillar feed continuously?
- After feeding does the caterpillar return to its original position on the tree?


5) Describe the behaviour of the caterpillar when it is ready to attach itself to the tree.
Why does it crawl away from its food source?
Why does it select a branch to attach that is not cluttered with leaves?

6) Offer an explanation as to how each behaviour helps the insect survive.

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