Grade by Grade
B. Life Systems · Growth and Changes in Animals

Insect Life Cycles: The Monarch Butterfly and the Grasshopper

B2.3 B2.4 A1.1About 35 minutes
Learning goals
  • I can name and order the 4 stages of a monarch butterfly's life cycle.
  • I can describe how a monarch's appearance and behaviour change at each stage.
  • I can compare a monarch's life cycle with a grasshopper's life cycle.

Words to know

life cycle
The stages an animal goes through from the start of its life until it is an adult that can make babies of its own.
stage
One part, or step, of a life cycle.
larva
The young, worm-like stage of some insects. A caterpillar is a larva.
pupa
The resting stage when a larva changes into an adult. A monarch's pupa is called a chrysalis.
metamorphosis
A big change in body shape as an animal grows, like a caterpillar becoming a butterfly.
nymph
A young insect, like a baby grasshopper, that looks like a small adult without wings.
milkweed
A wild plant. Monarch caterpillars eat only milkweed leaves.

A tiny egg on a leaf

In July, Maya found a tiny white dot under a milkweed leaf in a field. It was smaller than a grain of rice. Her grandpa said, "That is a monarch butterfly egg!"

How can a tiny egg become an orange and black butterfly? Let's find out.

What is a life cycle?

Every animal has a life cycle. It starts life, grows and changes, becomes an adult, and makes new babies. Then the cycle starts again, like a circle.

Each part is called a stage.

A monarch caterpillar with black, white and yellow stripes eating a milkweed leaf.
This is the larva stage of the monarch. The caterpillar eats milkweed leaves and grows bigger before it makes a chrysalis. AI-generated image
egglarvacaterpillarpupachrysalisadultbutterflythe adult has young, and the cycle starts again
The 4 stages of a monarch butterfly's life cycle.
StageWhat it looks likeWhat it does
1. eggtiny, cream-coloured, laid on the underside of a milkweed leafwaits a few days, then hatches
2. larva (caterpillar)worm-shaped, with yellow, black and white stripeseats and eats milkweed leaves and grows fast. It sheds its skin several times as it grows. This lasts about 2 weeks.
3. pupa (chrysalis)a green case with tiny gold dots, hanging upside downdoes not eat or move around. Inside, its body changes completely. This lasts about 2 weeks.
4. adult (butterfly)orange and black wings, 6 legs, antennaeflies, sips nectar from flowers with a long tube mouth, and lays eggs on milkweed
How a monarch changes at each stage

A huge change: metamorphosis

The caterpillar and the butterfly look completely different! When an animal changes its body shape this much, we call it metamorphosis (say: met-uh-MOR-fuh-sis).

Its behaviour changes too. The caterpillar crawls and chews leaves. The butterfly flies and sips nectar.

In late summer, many monarchs from Ontario fly all the way to the mountains of Mexico for the winter. That is thousands of kilometres!

A different insect life cycle: the grasshopper

Not all insects have 4 stages. A grasshopper has 3 stages: egg → nymph → adult.

A nymph looks like a small adult grasshopper, but it has no wings yet. As it grows, it sheds its skin several times. After its last shedding, it is an adult with wings.

There is no pupa stage. So a grasshopper does not change as much as a butterfly does.

eggnymph(no wings)adult(with wings)the adult has young, and the cycle starts again
The 3 stages of a grasshopper's life cycle. There is no pupa.
Worked example

Let's put the stages in order

These monarch stages are mixed up: chrysalis, butterfly, egg, caterpillar. Put them in order.

  1. What comes first? Every monarch starts as an egg.
  2. What hatches out of the egg? A tiny caterpillar.
  3. When the caterpillar is big, it hangs upside down and makes a chrysalis.
  4. What comes out of the chrysalis? A butterfly.
  5. Then the butterfly lays eggs, and the cycle starts again.

egg → caterpillar (larva) → chrysalis (pupa) → butterfly (adult)

Worked example

Let's compare the caterpillar and the butterfly

How are the monarch caterpillar and the butterfly different in appearance (how they look) and behaviour (what they do)?

  1. Appearance: The caterpillar is striped yellow, black and white with no wings. The butterfly is orange and black with 4 wings.
  2. Moving: The caterpillar crawls. The butterfly flies.
  3. Eating: The caterpillar chews milkweed leaves. The butterfly sips nectar from flowers.
  4. Same: It is the same animal! It is always an insect.

They look and act very differently, because the monarch goes through metamorphosis.

Just for fun

Knock knock.

Who's there?

Larva.

Larva who?

Larva you lots, Mom!

Hands-on activity

Butterfly life cycle research and spinner

You need: a paper plate, a paper fastener (split pin), pencil crayons, scissors, and a library book or website about monarchs.

  1. With a grown-up, find one new fact about each monarch stage in a book or a trusted website. Write it down.
  2. Divide the paper plate into 4 parts like a pizza. Draw one stage in each part, in order, going around: egg, caterpillar, chrysalis, butterfly.
  3. Cut a pointer out of paper and attach it in the middle with the fastener.
  4. Spin the pointer around the circle and tell the life cycle story, adding your new facts.

Bonus (late summer): With a grown-up, look gently under milkweed leaves for eggs or caterpillars. Look, but leave them on the plant.

Your turn

1

Name the 4 stages of a monarch's life cycle in order.

2

What is the only plant that monarch caterpillars eat?

3

What happens inside the chrysalis?

4

What does metamorphosis mean?

5

What are the 3 stages of a grasshopper's life cycle?

6

How does a monarch butterfly eat?

7

Why does a caterpillar shed its skin?

More practice: warm-up

1

What stage comes right after the egg for a monarch?

2

Does a caterpillar have wings?

3

What colours are an adult monarch's wings?

4

Where does a monarch lay its eggs?

5

What stage is a chrysalis: egg, pupa or adult?

More practice: on your own

1

Give one appearance change and one behaviour change from caterpillar to butterfly.

2

How is a grasshopper nymph different from an adult grasshopper?

3

Which life cycle has a pupa stage: the monarch's or the grasshopper's?

4

Why would there be fewer monarchs if people pulled out all the milkweed?

5

Why do we draw a life cycle as a circle?

Challenge

1

Kai says a grasshopper nymph and a monarch caterpillar are the same kind of stage. Do you agree? Explain.

2

A monarch caterpillar stage lasts about 2 weeks and the chrysalis stage lasts about 2 weeks. About how long is it from caterpillar hatching to butterfly?

3

Why do you think the caterpillar eats so much, but the chrysalis does not eat at all?

Check your understanding

Quiz

1.

What is the correct order of a monarch's life cycle?

2.

What do monarch caterpillars eat?

3.

What is a monarch's pupa called?

4.

Which insect has no pupa stage?

5.

Metamorphosis means...

6.

How does an adult monarch eat?

For parents and teachers

Big idea: All animals have a life cycle (B2.3). Many insects go through complete metamorphosis (egg, larva, pupa, adult), like the monarch, so the young look and behave very differently from the adult (B2.4). Others, like grasshoppers and dragonflies, have three stages (egg, nymph, adult), and the young look like smaller adults without wings.

Research (A1.1): Finding one fact per stage in a book or trusted site (for example the Canadian Wildlife Federation or Monarch Watch) practises a simple research process.

Accuracy notes: Stage lengths vary with temperature; "about 2 weeks" each for caterpillar and chrysalis is a fair summary. Monarchs are an at-risk species in Canada. Please do not collect them from the wild; look and leave them.

Common difficulties:

  • Saying "cocoon" for a monarch. Moths spin cocoons; a butterfly's pupa is a chrysalis.
  • Starting the cycle with the caterpillar. Ask, "Where did the caterpillar come from?"

How to help: Plant native milkweed in a sunny spot if you have a yard or balcony, and watch for monarchs in July and August.