The life cycle of a butterfly and moth

Peacock butterfly on flower
The adult butterfly or moth is the final stage of the life cycle (Photo: WTML)

Butterflies and moths are fascinating insects as they undergo metamorphosis. That means they change from one form to another during their life cycle!

What’s the difference between butterflies and moths?

Butterflies and moths belong to an order (or group) of insects called Lepidoptera. They all have six legs, four wings covered in tiny coloured scales, and a proboscis (a long, coiled mouth part) for drinking nectar from flowers. As a general rule:

  • butterflies are often brightly coloured and fly in the day. They have long antennae with little clubs at the ends
  • moths usually fly at dusk or at night (although there are some day-flying moths too), and they don’t usually have little clubs at the end of their antennae. Some have feathery antennae instead.

The life cycle of a butterfly and moth

Both creatures go through a very similar life cycle with four stages.

1. Egg

The female lays lots of little round or oval eggs and attaches them to leaves or stems.

2. Caterpillar (or larva)

The egg develops into a caterpillar, which is green or brown and sometimes stripy or hairy. This is the time for it to feed and grow so it’s quite greedy – you’ve all read The Very Hungry Caterpillar, right? Unbelievably, it can eat 27,000 times its own weight! All that pigging out means it has to shed its skin around four times as it grows, and these different stages are called instars.

3. Pupa (often called the chrysalis)

This is a rest stage in which the caterpillar develops a hard outer case and hangs around on a plant for a few weeks, or sometimes over the winter. During this time, something amazing is happening inside – it’s turning into a beautiful butterfly or moth! Many moth caterpillars, and some butterflies, spin a silk cocoon, or covering, around the pupa to protect it while this is going on.

4. Adult butterfly or moth

Once the butterfly or moth is ready, the case splits open and the insect pops out. At first its wings are all wet and wrinkly, and it has to pump fluid into them to help them expand. Then it has to wait for them to dry before it can fly away in search of a mate. After that, the cycle starts all over again.

Did you know?

  • Of the Lepidoptera, there are more than 2,500 species known as moths and 59 species known as butterflies.
  • Three times as many moths fly in the day compared to butterflies.
  • Butterflies and moths are under threat. They’re very sensitive to changes in the environment, and 4 species of butterfly and 65 species of moth have become extinct in the last 100 years. Give them a helping hand by finding out how to attract butterflies to your garden this summer.

Why not go on a caterpillar hunt, or see how many butterflies you can spot with our Butterfly iDial? Seen a really beautiful one? Don’t forget to post a picture on our Facebook page or on Instagram using #NatureDetectives.

Little kids will love making these butterfly footprints too!

Tell us about the butterflies and moths you've spotted

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