Why raise Monarchs at home?
In the wild, Monarch eggs and larvae have a very small chance of survival.
Several studies have documented mortality rates of over 90% during the egg and larva stages (Borkin 1982, Zalucki and Kitching 1982, Oberhauser et al. 2001, Prysby and Oberhauser 2004).
That means only 10% of eggs and caterpillars will reach adulthood!
Not only is it a fun activity for the whole family but you are actually helping out an entire species while witnessing the phenomena called complete metamorphosis.
Still not convinced?
What if I told you it’s easy to rear Monarchs at home? All you will need to get started is a ventilated box (deli containers work great), a few milkweed plants and, of course, your Monarch egg or caterpillar. The entire process from egg to adult butterfly takes about 1 month.
It's important to understand the life cycles of a Monarch before you get started. Monarchs go through complete metamorphosis in which there are four distinct stages of growth in one life cycle! These stages are: egg, the larvae (caterpillar), the pupa (chrysalis), and finally adult butterfly.
Life Cycle of a Monarch
Monarchs overwinter in Mexico and certain parts of Southern California. When they wake up from hibernation, they will intuitively head North and East to start laying eggs.
In March and April the eggs are laid on milkweed plants and it takes only 4 days for an egg to hatch!
According to Karen Oberhauser, leading monarch conservationist, captive monarch butterflies average about 700 eggs per female as opposed to 300-400 in the wild.
Monarch females usually lay a single egg on a milkweed plant on the bottom of leaf. So, when searching for eggs, don't forget to flip the leaf over! Eggs are very small and sometimes easy to miss!
Larval Stage (Caterpillar)
The larval stage last 2 weeks. Once the egg has hatched, a very small (and hungry) caterpillar emerges. During this time, the caterpillar will spend most of it's time eating so it will need fresh leaves everyday. As the caterpillar grows and becomes too large for its skin, it molts. The intervals between molts are called instars. Monarchs go through 5 instars. Click here if you'd like to learn more about differentiating the different instars.
Once the Monarch larvae has reached their final molting stage, they will spin silk from which they hang upside down by their last pair of prolegs and create a chrysalis. They will spend between 1 and 2 weeks inside the chrysalis.
Before the butterfly emerges, the chrysalis will turn from green to clear like in the picture below. Once adults, Monarchs will live another two to six weeks in the summer. However, the last generation of super Monarchs that complete the migration much longer, about six to nine months.
Materials Needed for Raising Monarchs
Make sure you have a local nursery that you can acquire milkweed plants from or you already have some established in your yard because Monarch caterpillars can eat up to 200X their own body weight! Click here for types of Milkweed that are suitable for rearing Monarchs.
2. Monarch caterpillars or eggs- These can be found outside on milkweed plants or purchased.
3. Ventilated container such as a deli container or aquarium works great. You can also buy butterfly houses like these.
4. Paper towels
5 Steps to Raising A Monarch at Home
Step 1: Find the eggs and/or caterpillars
The best way to do this is to visit milkweed plants daily that you know are already established and if you planned ahead, are already in your backyard! If you don’t have any luck finding milkweed plants or caterpillars, you can also order monarch rearing kits like this that contain caterpillars
Step 2: Choose a container
Put the eggs or caterpillars in a container and line with paper towels. Here are some great butterfly container ideas. Eggs only take 4 days to hatch and caterpillars will form a chrysalis within 2 weeks. Caterpillars have a HUGE appetite and can eat 200X their weight in Milkweed! A single caterpillar can easily defoliate a milkweed planted in a 1 gallon container so plan accordingly. Provide fresh leaves daily or enclose the entire milkweed plant! Larvae will survive best and attain a large size if you keep the food fresh, the container clean, and the humidity low.
Step 3: Clean the cage regularly
The caterpillars are eating constantly so they will generate a lot of frass (cute name for you know what). This frass should be collected every few days and you can replace the bottom of the container with more paper towels. You can even sprinkle it on your plants outside to give them a nitrogen boost!
Step 4: Keep feeding the hungry caterpillars!
It's important to remember that as the caterpillars get bigger, so will their appetite so keep a close eye on them and make sure you are providing enough fresh Milkweed. After the caterpillar reaches it’s 5th instar (molting stage) it will climb to the top of the container and begin spinning a beautiful silken chrysalis. It will not need any food at this stage so your job is mostly done!
Step 5: Release Your Butterfly Into the Wild
The chrysalis will turn clear before the adult butterfly emerges (fully metamorphosed). It is important not to touch them for at least 5 hours so their wings can dry. Keep an eye on the weather and do not release your Monarch if there is a storm on the horizon. You may need to move the butterfly into a larger container if this is the case such as an upside down laundry basket or a mesh cage.
Special thanks to Debbie Jackson of Monarch Watch for sharing her passion of rearing Monarchs
We also recommend Carol Pasternak's How to Raise Monarch Butterflies, an in-depth guide on Monarch rearing