Mourning Cloak Caterpillar Care: Helpful Tips

Are you looking to groom some mourning cloak caterpillars so that you can see these beautiful butterflies grace your garden this spring? Then this article is the perfect spot for you to get all your tips.

Butterflies are hands-down one of nature’s most beautiful creations in the insect world. If you find interest in raising butterflies from caterpillars, we have something in common. 

While caterpillars are easy to raise, one still needs to know how to care for specific species. In case you are planning to raise Mourning Cloaks, we have got you covered.

We will take you through the entire process of bringing up these beautiful creatures so that you can enjoy their beauty in your garden.

A Bit About The Mourning Cloak Butterfly

Scientifically known as the Antiopa species, the mourning cloak belongs to the genus Nymphalis, under the Brushfoot family and Nymphalinae sub-family. 

It’s easy to identify a mourning cloak – these beautiful butterflies have maroon or purple-brown wings with a bright yellow border.

A strip of black lies between the brown and the yellow, lined with white or blue spots.

However, there’s more to this butterfly than its beautiful appearance. Among all the butterfly species, this one boasts the longest lifespan.

This is because they enter a period of dormancy both during summer (aestivation) and winter (hibernation). 

Such behavior isn’t common among butterflies – most of them either migrate in winter or overwinter as eggs or pupa. 

The mourning cloak’s resilience against the cold weather deserves a special mention too. They can survive temperatures lower than -35°F while huddling inside tree cavities.

Their Lifecycle in Brief

The life cycle of a mourning cloak butterfly lasts about 10 to 12 months, during which they go through the same stages as any other butterfly.

Laid in spring, the eggs take anywhere between 4 to 14 days to hatch. 

The larvae develop through five instars, with the larval stage taking two to three weeks in total.

Once the larvae are full-grown, they enter a state of hyperactivity and wander around. Within a day or two, they enter the pupal stage. 

A mourning cloak butterfly pupa is usually around 0.8 inches long and hangs vertically, upside-down.

Mature butterflies can take up to early august to appear, although they might also emerge in June or July, depending on when the eggs hatched.

Caterpillar Care

Moving on, let’s now figure out how to take proper care of this species of butterflies. Here’s how you’re to go about it:

Females laying eggs

To collect mourning cloak eggs, you need to look out for a female butterfly laying them. Identifying the females isn’t hard if you observe their behavior a little.

 While the males are much more aggressive and seem to hassle the females often, the females aren’t as active and seem shy. Besides, male mourning cloaks drink water from shallow puddles, a behavior known as puddling.

The females lay clutches of eggs at the bases of host plant branches during late spring. You should especially check out plants with mature leaves in wet meadows and river valleys. 

Once you find the eggs, you may use a small paintbrush to gently move them to a Tupperware container with small holes for breathing.

Making an Enclosure for The Caterpillars

Now that you have the eggs, you need to prepare an enclosure for the larvae, i.e., the caterpillars. 

You may use a pop-up enclosure, an old aquarium, or a container made from nylon or a net. The caterpillars need to stay on a branch cut from a host plant. You can place them on it using a paintbrush as soon as the eggs hatch.

Take a bottle of water and submerge the cut end of the branch to keep it fresh. 

Make sure to use a foil to cover the mouth of the bottle; else, the caterpillars might fall in and drown. The container you use must be large enough to accommodate the bottle too.

Mourning Cloak Caterpillar Diet

So now you have a bunch of tiny mourning cloak caterpillars in an enclosure, but what do you feed them? Thankfully, the mourning cloak caterpillar food is quite simple as they mostly feed on leaves. 

In the wild, common species of the mourning cloak caterpillar’s host plants include deciduous trees like cottonwood, willow, hackberry, mulberry, hawthorn, paper birch, etc. You may also feed them flowers of knapweed and scabiosa plants. 

Adult butterflies of this species primarily survive on rotten fruits and tree sap. However, they also drink nectar from certain flowers like milkweed and red maple and often extract necessary nutrients from animal droppings.

Growth Stages

As mentioned earlier, the caterpillars go through five instars. They barely move during the first one. During this time, they just eat, produce frass, and develop. 

They outgrow their skin and shed it during every instar, which is a common behavior among caterpillars. Depending on the availability of food and the weather, it can take them around two to three weeks to go through all the instars.

The caterpillars tend to group up in clusters and feed together during most of the larval stage. This makes it easy to mistake them for tent worm and gypsy moth larvae, which show such social behavior as well. 

Once the caterpillars have finished the fifth instar and are ready to pupate, they’ll part ways and seek out suitable locations for pupating.

In this regard, you may also collect mourning cloak caterpillars if you’re having a hard time finding their eggs.

Care During Pupation and Metamorphosis

Now for the most interesting stage, i.e., pupation and metamorphosis. You know the caterpillars are ready to pupate when you see them walking all around inside the enclosure, making repeated trips. 

This is quite unlike their usual, sedentary nature, and hence easy to notice. This phase lasts for about 24 to 48 hours, after which they fixate on a suitable location and hang their bodies upside down. 

It’s a good idea to put these mature larvae in small glass jars covered with paper towels, where they can complete the pupal stage undisturbed.

If you use the jar and paper towel method, the caterpillars will usually hang from the paper. The actual transformation is easy to miss as it takes only a couple of minutes. 

However, try to keep an eye out since the process looks quite amazing. The pupa seems to pulsate shortly before the transformation.

Make sure not to disturb the pupae. You don’t need to feed them either, as they don’t eat during this stage.

Care When The Butterfly Emerges

The adult butterflies will finally emerge in early August. However, they’ll first build a chrysalis, about 10 to 14 days before the emergence. 

Wait for the chrysalis to harden; it usually takes a few hours, but there’s no harm in giving it a couple of days, either. Once it has hardened, move it to the larger container where you had initially kept the caterpillars. 

This would be especially easier if you had covered the glass jar with paper or provided a stick for the pupa to hang from.

Attach the chrysalis to the inside of the enclosure and wait for the butterfly to emerge. However, make sure there’s enough space around it – the butterflies emerging in crowded or cramped spaces often end up with stunted wings. 

When they emerge, you may notice a bright red or orange discharge. Don’t worry, and it’s just some leftover pigment, not blood.

The sight of a mourning cloak butterfly emerging from its chrysalis is truly one to behold.

It would exit the structure with a crumpled and damp body and quickly start pumping the wings until the wings reach their full size. This is why they need adequate space around them for proper wing growth.

Frequently Asked Questions

Wrapping up

As mourning cloaks are found all over North America, you likely won’t have much trouble acquiring their eggs and caterpillars. 

Putting some effort into caring for them will indeed pay off, for watching a beautiful and healthy butterfly emerge is a beautiful sight.

If you have been planning to add mourning cloaks to your butterfly collection, I hope this article has been helpful.

Reader Emails

Several readers have inquired with us about how to take care of their mourning cloak caterpillars and raise them to become butterflies.

Please go through the experiences of our readers, and you might just learn a new trick or two!

Letter 1 – Raising Mourning Cloak Caterpillars

Love your site
Dear Bug Guys,
I’ve been using your site for a little while now. I’ve even sent in a few pictures of some unknown eggs on Acer platanoides, but received no response. I’m not surprised though you guys seem so busy. I wanted to let you know how much your site helps me with my job. I work on a tree farm in Southern Ontario and it’s my job (among other things) to ID pests and disease on our trees at the farms. Your site has come in handy many times and I’ve been able to identify most ‘bugs’. I decided to grow on some Mourning Cloak Caterpillars that were destroying our Hackberry trees. Unfortunately due to my job requirements I had to destroy quite a few, but I saved some and in 10-15 days I should have some butterflies as they have just begun to develop into their chrysalis. I’ll try to send you a few pictures when they emerge. I used to grow caterpillars when I was a little girl just to see what they would turn into. Your site has re-inspired me to take up my childhood hobby. So thanks for having a wonderful site, keep up the good work. Not only do you make my job easier, you also make exploring the bug world fun. Thanks again,
Diane

Hi Diane,
It makes us feel quite guilty when we hear how disappointed people get when we can’t answer all of our mail. Hearing about disappointed children, sometimes entire classrooms of them, makes us wish we could hire a staff, but sadly, we cannot. We are intrigued with the re-inspiration of your childhood hobby of raising caterpillars, especially as we have researching the life of Maria Sibylla Merian in preparation for our lecture at the Getty. Merian used to collect caterpillars from throughout her hometown of Frankfurt and raise them so she could draw the various phases of metamorphosis. We are posting your letter to our third fanmail page.

Letter 2 – Mourning Cloak Caterpillar

Black caterpillar with barbed spines & red dots on its back
Dear BugMan,
Your site is FABUOLOS! I found this caterpillar in my backyard the other evening and took these pictures of it. I then proceeded to neglect my family because I spent a few hours browsing your site trying to identify it – I’m not a bug lover but I’m not a bug hater, either! Cool bugs are cool bugs and thank you for having so many bugs, cool & not so cool on your site! The closest I could find was the Pipevine Swallowtail Caterpillar. I do have a couple of Dutchmen’s Pipe vines so I was hopeful. Upon closer examination, it’s really only close, no cigar! The spines are barbed and I hope you can see from these pics that the spots are on the top of the body.. maybe I have a baby – still hopeful! The three caterpillars I’ve seen range in size from 1” to 1 1⁄2”. We live on Long Island, NY. I’ve seen 3 of these critters – never on any thing that they might eat – crawling across the patio, for example. Also not on or near my Dutchmen’s Pipe vines. The pictures I’m sending were taken of the caterpillar resting on a dead stick, also not near the Dutchmen’s pipe or near any other plants; the stick was on top of some rocks. Thank you for help with identifying this caterpillar and thank you for having such a fantastic website!
Patsy
L.I. NY

Hi Patsy,
This is a Mourning Cloak Caterpillar, which will become a beautiful dark butterfly with cream colored wing edges and blue spots. As the butterfly hibernates as an adult, it is often the first butterfly seen in the spring. The caterpillar feeds on the leaves of willow, elm and poplar.

Letter 3 – Mourning Cloak Caterpillar

Caterpillar
April 7, 2010
I’m wondering that kind of caterpillar this is, and what type of moth or butterfly it will turn in to.
I found it in my back yard, in the suburbs of Phoenix, Arizona.
It’s April (Spring, 85+ degrees today), and the caterpillar is about 1″ long.
I moved it twice so that my dog wouldn’t eat it… and this morning found it hanging from my back door readying itself for cocoon.
Thank you for your help.
LMK
Phoenix, AZ

Dear LMK,
Your caterpillar is a Mourning Cloak Caterpillar.  Mourning Cloaks are lovely purplish black butterflies with uneven cream colored borders and blue spots.  They are found throughout North America as well as Eurasia in the northern hemisphere.  In England, the Mourning Cloak is known as the Camberwell Beauty.  As we were doing research for our book, we learned that the Mourning Cloak Caterpillar is known as the Spiny Elm Caterpillar because if is often found feeding on elm tree leaves, though it will also feed on the leaves of willow.  It will not spin a cocoon, but it will form a chrysalis.

Letter 4 – Mourning Cloak Caterpillar

Caterpillar
Location: San Fernando Valley, CA
May 29, 2011 7:28 pm
My niece & I found this guy crawling around our porch. We can’t figure out what it is and would like to know what it eats as well.
Signature: KA

Dear KA,
We have seen numerous adult Mourning Cloak butterflies this spring.  They are medium sized dark butterflies with irregular pale yellow wing edges.  It makes sense that with numerous adults, there will be a population explosion of Mourning Cloak Caterpillars like yours.  They feed on Chinese Elm, though originally they fed on the native willow that grows along the water in riparian habitats.

Thank you so much for the immediate response. Hopefully we can see it turn into a butterfly soon 🙂

Letter 5 – Mourning Cloak Caterpillar called “horrific”

What is this???
Location: CA
July 26, 2011 5:37 pm
Curious as to identifying this horrific bug I took pictures of…
Signature: AP

Dear AP,
We can think of numerous things in the world that might be called “horrific” but the Mourning Cloak Caterpillar is not one of them.  We cannot imagine what incited you to use such strong language.  Mourning Cloaks are lovely dark purple butterflies with cream colored wing edges and tiny blue spots, and their populations seem to be high this year.  Perhaps it is related to the heavy rains in California this past season.

Letter 6 – Mourning Cloak Caterpillars

Subject: Morning Cloak Caterpillars?
Location: Saint John, NB Canada
July 30, 2014 6:40 am
I found this congregation of caterpillars on the branch of my willow tree last night. This morning they had abandoned that branch, leaving clumps of black, and had relocated to a higher branch. I am located in Saint John, NB Canada and have never encountered these before. Based on what I’ve seen on the internet, I believe they are Mourning Cloak Caterpillars but I was hoping someone could confirm that makes sense. I’m also wondering if these are dangerous and should heed any warnings. I’m not a creepy crawly fan so I haven’t gotten too close but I’ve taken a couple of photos zoomed in as much as possible.
Signature: Jennifer

Hi Jennifer,
Though you image lacks critical detail, there are enough similarities to presume these are Mourning Cloak Caterpillars.  Your very descriptive account of the sighting supports that supposition as willow is a common food plant.  Mourning Cloak Caterpillars frequently feed in a group, known as an aggregation, a more accepted term for a group of caterpillars than the term congregation.  Mourning Cloak Caterpillars are not considered dangerous, but the spines can cause a painful prick if they are carelessly handled.

Letter 7 – Mourning Cloak Caterpillar

Subject: Caterpillar identification
Location: Southern Wisconsin
June 8, 2015 2:19 pm
Just wondering what this is and what it will be
Signature: Curious

Dear Curious,
This is the caterpillar of a Mourning Cloak, sometimes called a Spiny Elm Caterpillar.  The adult Mourning Cloak is a lovely butterfly that hibernates over the winter, and they are sometimes seen flying on warm, sunny, winter days, even when there is still snow on the ground.  Before flowers begin to bloom, they take nourishment by drinking sap that flows from the trees in the spring.