From Egg to Monarch in 30 Days

July 2009

Julie with a butterfly on her finger
Julie with a butterfly on her finger

Raising a monarch butterfly from an egg to a butterfly is an amazing process to observe. It only takes a month to see all the stages: egg, larvae (caterpillar), chrysalis, and butterfly. Here’s the full story of the experience Bob and I shared. Some of it has been reported elsewhere, but I thought it would be nice to have it all in one place. I hope this information is useful to anyone wishing to try it themselves. If you want to skip to the visuals, here are some photos and videos that take you throught the stages. I wish I’d taken more, but once the butterfly takes off, it’s gone, and you just have to wait until the next time.

We have a field down the street from our house that has stormwater containment ponds. They are meant to handle the runoff from downtown Wheaton, which has so little green space any more that there’s nowhere for the water to go but into the creeks that meander through the neighborhoods. In some places, the creek acts as a median strip in the side streets. Erosion could threaten these streets when a heavy rain comes through and has nowhere to go but over the banks. The stormwater ponds aren’t the best solution (that would have been to allow for a lot more green space within the town), but it gives the water above them a place to go, and controls the amount of flow into the creeks below them. A side benefit to this environment is that it attracts a lot of wildlife to our neighborhood: deer, geese, herons, beaver, foxes, and butterflies. There are lots of trees around the edge, and wildflowers such as milkweed.

The county maintains the land where the ponds are located, and their primary concern is the integrity of the dams that hold the water in. The biggest threat to the dams is woody vegetation growing on them that might break up the walls if allowed to get too big. So, occasionally, they have to mow them. Last month, when I saw that all the milkweed had been mowed down, I became concerned for the monarch butterflies.

Butterflies have an interesting relationship plants. There are two purposes for plants in their life cycle. As butterflies, they drink the nectar from just about any flowering plant. But they only lay their eggs on certain plants, because the caterpillars that hatch out of them will only eat specific plants. Black swallowtailed butterfly caterpillars favor parsley. If you notice that something is chewing the heck out of your pansies, look around for the caterpillar of the variegated frittilary. Monarch butterfly caterpillars only eat milkweed.

There are lots of varieties of milkweed: swamp milkweed, showy milkweed, butterfly weed. Often, you can find these at nurseries that promote butterfly gardens. But what they had at the pond, was common milkweed, and I was having a hard time finding at the usual sources. So, I contacted the instructor for a class I took through the Audubon Naturalist Society a few years ago on the natural history of butterflies. She has a greenhouse where she raises all sorts of butterfly friendly plants. I drove out to her home on June 18 and bought several plants, including three common milkweed.

As soon as I got home, I planted them all. The next day, while I was at work, Bob observed a monarch butterfly sit on one of the plants for a short time and then fly away. When I got home, we searched the plant for eggs, and sure enough, there were tiny white orbs, about the size of a poppy seed, sitting on some of the leaves. We took two of them inside and adopted them.

It wasn’t possible to tell the gender of the caterpillars that came out two days later, so we gave them the names Tex and Slim. I knew that the next phase of their lives was to ride those milkweed leaves (and eat them) for the next couple of weeks, so I dubbed them The Milkweed Cowboys. Yahoo! Git along little larvae!

I kept the cowboys in a plastic box my brother gave me, that was left over from when his kids had hermit crabs. It was an excellent way to watch their development, and also keep the cats away from them. Occasionally, I took the caterpillars out to photograph their progress.

They started out so tiny, but they grew to their full size in just two weeks. We had to keep them supplied with fresh milkweed leaves. I didn’t want to use up all the leaves on my own plants. I went back down to the pond to pick some of the milkweed leaves off the plants there. The mowing hadn’t killed the plants, and they were sending up new tender shoots. I picked leaves off of what I thought were small milkweed plants coming back up, but they were not. They were in the same place, and the leaves had the same shape. But the cowboys were not fooled, and they refused to eat them. I told you they were particular! I started giving them leaves from my garden, but I wasn’t happy about it. After a few days, I went back to the pond, and the common milkweed had grown enough to be distinguishable from the false milkweed. I brought back a lot of leaves, some of which I kept in the fridge for later. It was a good thing that I had done that, too. One morning I got up to find that the caterpillars had eaten the leaves all the way down to the stems, and had doubled in size. If I hadn’t had a few leaves chilling, I would have had to get dressed and go to the pond and get more before I had to go to work.

Then, after two weeks of feeding them, I saw the caterpillars start climing to the top of the box, looking for a place to hang upside down. The chrysalis stage was about to begin. I had to go to work, and couldn’t photograph the process. Bob emailed me with the play by play as the caterpillars morphed into chrysalises:

12:15 still a caterpillar
12:57 wow, now it’s a cocoon, although you can still kind of see where the legs are.
1:04 the legs are disappearing before my very eyes
1:23 looks like its done!

I only took one photograph of the chrysalises because to do that, I need to remove the lid from the box. They were hanging from the underside of the lid, and if the chrysalises had become detached, it wasn’t likely that we would have butterflies at all. However, I know that in the wild, the chrysalises have to survive wind and rain, and who know what else. I figured if I was very careful, I would be able to get this one shot. I made two piles of books and separated them just enough so that I could set the lid on them and the chrysalises would hang undisturbed for their photo opportunity. The jade-like color with a line of tiny gold spots was a lovely sight to see. I almost wanted to wear it like jewelry.

Nothing at all happened to the chrysalises until the evening of the 28th day since we found the eggs. I saw that they were starting to darken, a sign that the next day would be the one when the butterflies emerged. I had raised a couple of butterflies several years before, but at that time, I lived alone. Everytime something big happened in their life cycle, I was out of the house. This time, I saw a lot more with my own eyes. And even when I didn’t, Bob did and his descriptions were fascinating. This time, the emergence was going to happen on a Saturday morning when I had no plans, and the weather was lovely. A perfect time for a butterfly release party!

By morning, the chrysalis had become so transparent that you could see the familiar orange and black pattern of the monarch’s wings. When the time came to emerge, it only took a second for the butterfly to split the chrysalis, step out, and then hang from it. When it first emerges, the wings look tiny and shrunken, and the body is big and fat. Somehow, the fluid in the body is pumped out to the wings, and in a matter of about ten minutes, you have a normal-looking monarch butterfly. The wings take about two hours to dry enough for flight. You can tell that the butterfly is ready to be released when it stops hanging upside down like a piece of laundry, and sets down right side up and begins looking for a way out of the plastic box.

Around 11:00 a.m., on a sunny Saturday with light breezes, we took the butterfly box out to the yard. I removed the lid, and put my finger down to the most active of the two butterflies. It crawled onto my finger and I lifted it from the box. From there, I set it down on a zinnia. With the flapping of the wings, I was able to determine that the first one I released was a male. There were two wide spots in the stripes of the hind wings which can only be seen when the butterfly opens its wings. Butterflies can only fly when their muscles have been warmed enough to work, so I decided to move the butterfly to a flower in the sun. I didn’t get a chance to complete my plan, because he chose that moment to fly for the first time. He went high up into my neighbor’s cedar tree, and I never saw him again. But at least I got some good photos of him while he was still sitting on the zinnia.

With the second butterfly, I took the box to the front yard where it was very sunny, and let her warm up. Before I let her out, I took a movie of her flapping her wings around in the box. Then, she climbed up on the stick that I had put in the box for them to perch on. I opened the box and lifted the stick out. She immediately flew off, heading across the street, almost become a splat on a passing car’s windshield. However, she made it off to the trees beyond the road, and she, too, was never seen again.

I helped one male and one female survive the most vulnerable stages of their lives. As eggs, caterpillars, and chrysalises, they could have been eaten by a predator. Although the milkweed makes them toxic and untasty to birds, it’s still a risk. And life as a butterfly isn’t without its risks as well. Still, it was a beautiful thing to observe, and I’m glad I got the chance to see it.

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