The Monarch Butterfly Project

I didn’t necessarily intend to become a crazy caterpillar lady.  But this past spring and summer it happened. In the past I’ve come across a monarch caterpillar or two and have watched them, along with my two kids, transform into a butterfly.  This year a bunch of the milkweed seed planted last fall came up in different spots in our yard. And so began this year’s monarch butterfly project.  

It’s relatively easy to find and care for eggs which become monarch butterflies.  If you’re interested in raising caterpillars until they emerge as butterflies you’ll need milkweed.  That’s the plant female monarchs seek out to lay their eggs. Those eggs hatch and the caterpillar’s only goal is to eat the leaves of the plant and grow.  They eat. And eat. And eat. They don’t eat the variety that Eric Carle’s Hungry Caterpillar consumes, but they do munch on quite a bit of milkweed throughout their life.  

Once milkweed has started growing in the spring it’s almost time to start looking for monarch eggs.  You may even catch a glimpse of a female laying her eggs, typically on the underside of the leaves. The eggs will look like small, white dots, but they’re pretty easy to spot.  Once an egg is placed on a leaf it’ll take about four days before a caterpillar is born. Female monarchs can lay up to a couple hundred eggs, although not many will make it out of the egg.  Some will be eaten by predators while others just aren’t viable. If you’re planning on searching for eggs and collecting them, pick milkweed leaves with eggs and put them in a safe spot. Depending on how many eggs you plan on collecting, some people put them in Mason jars with damp paper towels.  Others use butterfly enclosures. I used an open, plastic container for leaves with eggs on them, wrapping the bottom of the leaves in wet paper towels so they wouldn’t dry out too quickly.

Once caterpillars hatch they’ll go through five instars, or shedding of their skin before they’re fully grown.  Caterpillars will eat for 10-14 days before they’ll hang in a J, signaling they’re ready to form a chrysalis (moths form cocoons).  After hanging for about a day, they’ll form a chrysalis. If you’re not watching it’s easy to miss this process. It only takes about five minutes from start to finish as seen in this video.  One sign to look for are droopy antenna followed by a little wiggling by the caterpillar.  The green chrysalis will start to form at the bottom of the J and move upward. It will look bumpy for a couple of hours before it becomes smooth.  If you look closely you can even see the wings of a butterfly already formed within the chrysalis.   

Once a chrysalis is formed, there won’t be anything to watch for another 10-14 days before the monarch butterfly ecloses, or emerges.  The chrysalis will begin to darken and actually look clear about a day before the butterfly is ready to come out. You’ll be able to see the black and orange of the wings before it’s ready to come out.  Once a crack starts to form at the top of the chrysalis a butterfly should eclose within an hour or two. I was able to catch only one butterfly coming out of a chrysalis as seen in this video.  This stage happens even faster than forming a chrysalis!  The butterfly will almost seem to pop out and then hang from the chrysalis as its wings expand and dry out.  After about two hours he or she be ready to take flight.  

I usually left newly eclosed butterflies in the enclosure until they were ready to fly as this kept them in a safe place.  If any happened to emerge late in the day and wouldn’t be ready to take flight until it was near dark, I kept them overnight, again giving them a better chance at survival.  Monarch butterflies only live for 2-6 weeks. Their sole purpose it to reproduce and start the process all over again with the exception of those which emerge late in the summer or early fall.  The last batch of monarch to eclose will not become sexually mature right away. They’ll migrate south to winter in a warmer location. In the spring they’ll head north and reproduce so their life cycle can begin again in warmer northern temperatures.  

It’s relatively simple to tell a male from a female when observing a monarch.  Males will have a black dot on their lower wings, which is easy to see when they’re not folded up.  A female’s black lines or webbing is also typically thicker compared to that of a male.  

This year I raised and released a total of 48 monarchs from egg to butterfly.  Only one caterpillar died before forming a chrysalis. Every caterpillar which formed a chrysalis eclosed.  Typically the split between males and females is 50/50 but I had a run of females in the beginning and ended up with 31 total compared to 17 males.  The first butterfly eclosed on July 3 and the last was on October 14. The last was relatively late in the season and with the colder weather that week she ended up sticking around for four days before it was finally sunny and a bit warmer even though I attempted to release her each day.  Temps should ideally be in the 60s for monarchs to fly but they can still make due when it’s in the 50s, especially if it’s sunny. Hopefully she was still able to find her way south!

The final step of the process of raising monarchs is preparing for next spring.  Milkweed seeds are released from pods in the fall. They need to winter in the ground or they’ll need to go through in-home cold stratification.  I prefer to let nature do her thing and harvest seeds in the fall and sprinkle them around in my gardens before the ground freezes. I hope to have enough milkweed plants next year to start all over again.