Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Martin Fennell on 15/05/2008 09:19:58

Title: Why do caterpillars have so many legs?
Post by: Martin Fennell on 15/05/2008 09:19:58

Martin Fennell asked the Naked Scientists:

Hi

My 9 year old son Matthew asked me:

"If Insects have 6 legs, why do caterpillers have so many legs?"

I am afraid I could not answer him. Can you help?

Thanks

Martin


What do you think?

Title: Why do caterpillars have so many legs?
Post by: Kryptid on 15/05/2008 12:31:06

Technically, caterpillars have only 6 "true" legs (the ones closest to the head) that are attached to the caterpillar's thorax. The rest of the legs are "false" legs or (prolegs) that grow from the caterpillar's abdomen, and vary in number from species to species. The distinction between the thorax and abdomen in caterpillars is not easy to spot at first glance, but looking at the legs can tell you where it is. The true legs on a caterpillar are the same legs that you see on butterflies (the prolegs are deleted during metamorphosis). The prolegs differ in structure than the true legs as well. Although you might think of the prolegs are being little "suction cups" that allow the caterpillar to cling, that isn't technically true. The prolegs actually stick to things because they have microscopic hooks on them.

So it's probably better to say that insects have 6 "true" legs.

Title: Why do caterpillars have so many legs?
Post by: DoctorBeaver on 16/05/2008 06:54:56

Can you imagine how difficult it would be for a caterpillar to balance on 2 legs?  [:D]