5 Steps to Rearing Monarchs At Home

Photo by Debbie Beal.

In the wild, Monarch eggs and larvae have a very small chance of survival. In fact, studies show that 90% of Monarchs do not survive the egg and larva stages. 

Each of us has an opportunity to make a real difference for the Monarchs. We would like to encourage each of you to join  the Monarch  Catch and Release Program, whereby each of us finds either eggs or caterpillars and raises them to adulthood."
​- Ward Johnson,
director of Save Our Monarchs

Rearing monarchs in the classroom or at home is a highly valuable educational tool for teachers, parents, and citizen scientists. This activity helps students to understand the monarch life cycle, witness the phenomenon of metamorphosis and deepen their connection to the natural world. However, Save Our Monarchs Foundation does not support large-scale captive rearing of monarchs as a conservation strategy.

There are several known risks of large-scale captive rearing of monarchs. These risks include increasing diseases and parasites in wild populations and causing the captive monarchs not to migrate. Due to the lack of scientific evidence supporting the practice of rearing monarchs to increase overall population, we support this activity only in a limited capacity as an educational tool.

In addition to our educational mission, Save Our Monarchs is dedicated to utilizing conservation strategies for increasing monarch populations. These strategies include creating new biodiverse pollinator habitat, improving existing habitat, raising awareness about monarch conservation, and providing milkweed and other native plant seeds to the public. ​

Materials Needed

1. Ventilated container
​You can now buy these enclosures on our website!
You may also use aquariums, deli containers, clothing hampers but make sure they are clean and well-ventilated. 
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2. Paper towels or Newspapers
This is for lining the cage and simplifying clean-


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3. Monarch caterpillars or eggs 
These can be found outside on milkweed plants. Look carefully on the underside of leaves and on flower buds for eggs and larvae. Our blog will help you find them! 


4. Milkweed 
​This can be grown in your own backyard or bought from a nursery. If you choose to buy from a nursery, make sure you ask if it has been sprayed with any pesticides which can be fatal to monarch caterpillars. Often nurseries will spray all of their plants with pesticides so your best bet is to grow it yourself.  Plan for at least one plant per caterpillar. 

5 Steps to Rearing Monarchs

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 ,hopefully, already in your backyard! If you see a Monarch land on your milkweed plant, it is very likely they left an egg behind so check right away. Carefully look on the underside of the leaf, where they often lay eggs. 1st instar caterpillars and eggs are TINY so look very closely.

Step 2: Put milkweed cutting in water and put them in a ventilated enclosure.

Once you find a caterpillar or egg, cut off the entire leaf or branch that the egg or caterpillar is on, and put it in a glass of water to keep the cutting fresh. Put the eggs or caterpillars in the ventilated container of your choice after lining with newspaper or a rubber mat (for easy clean-up). 

It is best if you keep the monarchs exposed to as much natural like as possible. A sheltered location outside, a patio or screen in porch are the best options. However, you could also put your enclosure next to a large window so the caterpillars are exposed to natural light and as little artificial light as possible. The reason for this is because recent studies have found that monarchs that are exposed to artificial light do not develop their navigation skills needed for migration. 

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 other day in order to keep the larvae healthy and prevent diseases from spreading. You can simply replace the bottom of the container with more paper towels or newspaper paper for easier clean-up. Just throw the frass into your compost bin to add nitrogen!

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 it's silk pad. 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

Please note that even in captivity, Monarchs can develop diseases, parasites, bacterial infections and other illnesses. The best way to prevent this from happening is to keep a very clean cage that is kept dry and not humid. For a list of common monarch ailments click here. 
Furthermore, we do not support large scale monarch breeding operations or the sale of monarch caterpillars. We DO support responsible rearing of monarchs, especially in an educational environment.  

Monarch Life Cycle

​Eggs only take 4 days to hatch and caterpillars will form a chrysalis within 2 weeks. The butterfly will then emerge from it's chrysalis after 10-14 days, making the entire metamorphosis process just over 1 month! 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.

Egg

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, Monarch biologist, 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. 

Pupa (Chrysalis)

The chrysalis is green with a golden diadem at first.

The chrysalis turns clear within 24 hours of opening.

Once the Monarch larvae has reached the final molting stage, they will hang upside down by their last pair of prolegs and create a chrysalis. They will spend between 1 and 2 weeks inside this chrysalis.

Adult Butterfly

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.
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Resources

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

Kelly R. Nail, Carl Stenoien, Karen S. Oberhauser, Immature Monarch Survival: Effects of Site Characteristics, Density, and Time, Annals of the Entomological Society of America, Volume 108, Issue 5, September 2015, Pages 680–690, https://doi.org/10.1093/aesa/sav047
University of Minnesota Monarch Lab. Monarch Life Cycle.
https://monarchlab.org/biology-and-research/biology-and-natural-history/breeding-life-cycle/life-cycle/#adult

Ecology Online Sweden. 2004-2012.
​ http://www.ecology.info/monarch-butterfly-page-3.htm