How to Raise Your Monarch Butterflies
It’s late summer now, and there are still weeks to go before thousands of monarch butterflies start their 8,000 kilometre migration to wintering grounds in Mexico.
As of last week, five of my monarchs have hatched from their chrysalises and taken flight, and two more sleep in their chrysalises awaiting their turn.
Earlier this summer, I decided to raise monarch butterflies and document their growth and metamorphosis.
Why do this?
Well, I used to raise monarch caterpillars as a child. It was always a magical experience.
Last year the fatality rate for monarch caterpillars munching on the milkweed in my parents’ backyard was 100 per cent. The dozen or so caterpillars my parents had been observing disappeared overnight.
Monarchs are threatened by many dangers; pesticides, predators, lack of wildflowers and climate change.
A friend sent me this article in the Walrus, which sums up the current situation quite well and is a good read. I wish I’d written it!
Since I was staying at our family home during the pandemic, I thought I’d try being a butterfly dad.
I’m writing this post as a summary of this experience and as a guide to raising baby monarchs.
What you need:
1) A good, local supply of milkweed (at least four plants).
2) A container of some kind that can be sealed (caterpillar proof), lets in light, offers good access to the caterpillars, and is relatively easy to clean (there are good options online that you can buy).
3) Monarch caterpillar eggs or monarch caterpillars.
Eggs: 4 days
Monarch butterflies lay eggs singly on the upper or lower surface of milkweed leaves.
Common milkweed is, well, common (there are many milkweed varieties). You can find it in roadside ditches and open fields of tall grass. Just do your best to find a milkweed patch that hasn’t been sprayed with pesticides.
If you’re thinking ahead to next year, you can gather seeds from milkweed seed pods in the fall and plant them in your garden.
The eggs are cream-coloured and slightly conical, pinhead-sized.
I found five monarch eggs and cut them off the rest of the leaf with scissors. I placed them in a tupperware container indoors (don’t worry, little eggs and caterpillars don’t need much air). I opened the container up twice a day to check on them and made sure to put a drop or two of water on the paper towel.
When the eggs are ready to hatch they will turn gray, with a black dot near the tip.
In my case, the pieces of milkweed the eggs were attached to were quite shrivelled by then, so I trimmed the pieces of leaf even further and put a fresh leaf under them (I didn’t want them to be eating stale leaves).
Also, keep the eggs spaced apart. The first thing the little guys eat when they hatch is their empty eggshell. If their unhatched siblings are too close they might be tempted to try a forbidden and nutritious treat!
Caterpillars: 12-14 days
Okay, so caterpillars moult their skin to grow bigger. Monarchs do this five times. The period between moults is called an “instar”.
The first day after they hatch the caterpillar will be tiny and gray. They won’t get their yellow, white and black clown costumes on until a day or so later.
So tiny!
The caterpillars are very delicate at this stage so be very careful when transferring them to fresh leaves. I personally found this the most finicky part of the whole process.
The leaves wilt after a day and it’s important that the caterpillars have fresh food. So I changed the leaves every morning.
The poop also needs to go. If it isn’t cleaned up the caterpillars might get sick (and there are no caterpillar veterinarians).
I kept them in the tupperware container for more than a week after hatching. I was a little worried at how hot it was outside.
5th instar caterpillars. Big bois.
Once the caterpillars reached about two inches long I transferred them to a mesh-and-wood bug box outside.
By this time the caterpillars have got eating down to a science. If you have more than a couple caterpillars in your enclosure you’ll be amazed how much they can eat (and poop).
The caterpillars might not all grow at the same rate. It’s possible for monarch caterpillars to vary greatly in size.
Hanging up:
When they reach maximum size the caterpillars will grow restless and start roaming around the high places in the terrarium, looking for a good spot to spin a silk anchor and hang upside down.
Be sure to give them something to hang up from. It could be some sticks, some newspaper, netting; anything that gives them some grip.
In my bug box three of them tried to hang from the ceiling at the same time. Every time two caterpillars bumped into each other they would rear up like bears and jerk forwards as an intimidation tactic. I imagined them hissing and spitting at each other.
Eventually all three settled down quite close to each other.
Each caterpillar spins silk from its mouth to form a base of support, attaches its rear to an anchor point and lets go. They hang there, in a “J” shape, for roughly a day.
Then they shed their skin for the final time. The process happens FAST; perhaps 120 seconds in all.
Just before the moulting takes place, the caterpillar will start twisting and moving around.
In my experience it usually happened mid-morning.
The caterpillar stretches out and begins to turn green underneath its skin. The empty “head” pops off and the skin unzips like a clown-themed dress. Underneath the caterpillar already has some of the shape of the butterfly it will become!
As it hardens it shifts its shape into the sleek emerald and gold form it will hold for the next 9 to 14 days.
Chrysalis State: 9-14 days
If all the caterpillars are in chrysalis state, now’s a time to relax a bit, bug parents. The kids are asleep!
The chrysalises are BEAUTIFUL. Jade green and gold jewels that hang from white silk. When the butterfly is ready to emerge, the chrysalis will darken and become translucent before turning completely transparent.
On most days I tried to keep the bug box out of direct sunlight. The chrysalises don’t need any care other than that.
The silken anchor is fairly strong and can stand up to high winds etc.
Stay calm, everyone. It’s going to be okay.
If the chrysalis falls or is knocked down, don’t panic. You can reattach the silk anchor it to a stick or roof with tape or thread. Just be VERY gentle with the chrysalis while doing so.
Whew! Fixed! And no harm done.
Hours before the butterfly hatches the chrysalis will become completely transparent. You can see the shrunken wings, compound eyes and fat body of the butterfly within!
Butterfly Emergence: 2 hours in total
The chrysalis is completely clear now, with a thin clear membrane separating the butterfly inside from the outside world.
In my experience the butterflies made their move in the morning.
That magical moment of initial emergence happens very quickly (perhaps 60 seconds in all) so I’d advise keeping the chrysalis nearby if possible so you can keep an eye on it.
After emerging it will spend about two hours pumping blood into its wings and drying off.
Shortly before its first flight, the butterfly will become restless and climb for a higher vantage point. Just before taking off, it will flap a few times, then fly for the first time.
It’s a great moment, watching that butterfly soar away into a world it’s seeing through new eyes.
It’s now done with chewing leaves. For the rest of its life it will be sipping nectar cocktails and hitting up the singles bar.
If the hatching takes place in June or July these butterflies will likely mate and lay eggs in the area, raising another generation. It’s only the fourth and last generation of the summer that starts the migration south to Mexico.
If you have read this and believe you have the tools to raise monarchs, just go for it. If ten-year-olds can do it without ill effect, you can too. You’ll be dramatically increasing their survival rate and helping a species that has been very vulnerable to harm over the past few years.
If you’re not up to hand-raising monarch butterflies, I’d encourage you to plant some milkweed anyways. It’s relatively hardy and attracts a huge range of native pollinators. I saw many species of bees, moths, wasps and butterflies I would never see otherwise.
Goodbye Butterfree! I’ll never forget you!
