raising monarch butterflies from-eggs life cycle

Raising Monarch Butterflies from Eggs

Collecting Monarch Eggs

monarch caterpillar

I've been watching my milkweed patch for monarch butterflies because I wanted to raise some from eggs. I finally spotted one flitting from milkweed to milkweed. It's been a really dry season and there have not been a lot of any butterflies this year except for the cabbage butterflies.

Wild butterflies face a great number of dangers and only a very small fraction of eggs laid become adults. This year competition for food is fierce among predators because of the lack of greenery.

All the plants are patrolled by ants and wasps and lots of spiders, plus countless other unidentified bugs. I'm usually happy to have the garden patrolled because it means fewer pests in the garden but I wanted to collect the monarch eggs before they got eaten or parasitized and raise them in a safe place, then release the mature butterflies. Spiders and Ants eat the larva and many insects will either eat the caterpillar or will lay their eggs in them. Because I've been watering this small wild flower garden it is full of life.

Birds tend to stay away monarch butterflies and larva because they have learned that they make you sick if you eat them. Milkweed is poisonous and the caterpillar absorbs the poison and pass it on to the adults. After being sick once, the birds recognize the bright colour pattern of the monarch and avoid them. Such colour patterns are referred to as aposematic.

monarch laying eggs

The monarch went from leaf to leaf and hung on to the edge. She then laid an egg on the bottom of the leaf. I've only found one egg on a leaf at a time.

monarch egg I will raise

To collect the eggs I got my glasses, some scissors and a plastic container. The monarch eggs are small, about 1mm across or even less. They are cream coloured and translucent. They were not all the same size some were quite small and others about twice the width.

Eggs are usually laid towards the top of the plant and usually on the bottom of the leaf.

monarch butterfly caterpillar

I had watched her and went to those milkweed plants first. I expected all the eggs to be on the underside of the leaves but one was right on top. I struck gold and found 8 eggs and the tiniest caterpillar I have ever seen.

He was not any longer than 3 mm. I cut out the section of leaf where he was sitting along with the pieces of leaves where the eggs had been attached.


To be successful in raising monarch butterflies from eggs you have to have a steady supply of organic milkweed to feed them. My patch was flourishing and had come back with a vengeance. Lucky because the new seeds I had planted had not come up very well because of the drought.

As a bonus, the plants flowered and attracted more bees and little skipper butterflies, than any other on the property except the catnip patch.

Here is my page about growing milkweed.

Eggs hatch and larva (caterpillar) starts eating

Milkweed flowers attract bees and butterflies

I put my pieces of leaf with eggs into plastic containers. I had prepared them by putting a damp paper towel in the bottom.

The leaves have to stay fresh until the eggs hatches then I can feed the tiny monarch larva new leaves.

Eggs take 3-4 days to hatch. It depends on the temperature. The eggs get a little dark spot at one end and the tiny caterpillar comes out.

His job then is to eat as much as he can and grow. He will have to moult 4 times, each time shedding his skin and growing. Eventually after about 2 weeks he'll make himself a cocoon and and emerge a fully grown butterfly about 2 week later.

I don't think that raising monarch butterflies from eggs is particularly difficult but you have to keep them clean and fed, just like regular babies really.

Scientists call the different sized caterpillars instars. Each time they moult it is a new instar. The caterpillar that has just come out of the egg is the first instar, after the first moult it becomes a second instar, and so on.

The caterpillar is called a larva, while the cocoon is called a chrysalis.

day 2 caterpillar

Little caterpillar is a day old and has eaten a huge amount. He's munched all the irregular section of the leaf. He has pretty much doubled in length too. It's quite amazing how fast this little first stage instar has grown.

Growing fast makes a lot of sense. The faster he can get bigger, the less time he has to get eaten by predators and the more likely he is to survive long enough to reproduce.

Middle sized caterpillars

These little guys about just short of an inch long. They have moulted twice already.

moulting caterpillar

This caterpillar is in the process of moulting. I expected the caterpillars to shed their skins but that's not what happens. When they decide to moult, they stop eating and move off to the side. Several climbed up to the top of the container and went sort of dull coloured and their antennae went floppy. The next day they were back eating and the only sign that anything had happened was a little black bundle of old head parts on the bottom of the container. They somehow re-use their skin.

head parts

Discarded head parts can be seen after a caterpillar has moulted. I guess they can't re absorb the head parts.

monarch eating

The caterpillars are absolutely frantic about eating. In a day they will easily eat their weight in milkweed leaves. They grow really fast and in one day you can see a significant difference. In the period of 10-12 days they go from about 1/16 of an inch to as much as 1 1/2 inch long.

This caterpillar has moulted 4 times and is referred to as a fifth instar. Shortly he will change his shape and become a crysalid.

monarch droppings

With all this eating comes a lot of droppings. This caterpillar produced this poop in less than one day, in fact there is more than the photo shows. I cleaned the containers every day.

Caterpillar droppings are referred to as FRASS.

monarch on lid

The day after the last photos, the caterpillar stopped eating and went to the top of the container and attached himself to the lid with silk. He attaches himself by the rear end. In this photo this is on the right. You can barely see a little silk button.

This silk attachment is really strong. At first he is stretched out on the lid, but later he drops and dangles from his bottom end in a sort of J shape. All this takes about a day.

At first if I touch them gently they sort of respond but later they don't seem to feel the touch.

monarch on lid

The caterpillar gradually lets go and starts dangling. After a few hours he will be in the J position.

Monarch Butterflies PART 2

email me if you find mistakes, I'll fix them and we'll all benefit: Christine