Mourning Cloak Caterpillar

Mourning Cloak?
Location: Denison, Texas
April 5, 2012 6:08 pm
I have seen about 13 of this in one afternoon crawling around. Is this a mourning cloak? Can they hurt you?
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Mourning Cloak Caterpillar

You are correct.  This is a Mourning Cloak Caterpillar.  They can often be present in great numbers as you have witnessed.  According to the Auburn University webpage on Stinging Caterpillars:  “Several species of nymphalid larvae bear conspicuous bristled or multi-branched spines similar to those found on some stinging caterpillars. One species, the spiny elm caterpillar (larva of the mourning cloak butterfly), is reported to possess urticating spines.”  According to BugGuide:  “Caution: Do not touch the larva; its spines may cause a stinging sensation if handled.”

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BugMan aka Daniel Marlos has been identifying bugs since 1999. WhatsThatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

41 thoughts on “Mourning Cloak Caterpillar”

  1. I find it so weird that these are poisonous caterpillars because when I was about 12 I caught 5 of them, played with them and touched them a lot. Nothing to my memory ever happened to me.

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  2. There are several “families” of them in a tree in my front yard — yes, hundreds of them! 🙂
    – Southern California

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    • Some have begun leaving the tree. I missed the mass migration on Monday, the 30th, but yesterday I saw some going off to find a place to make their chrysalises. They move quickly! But there were blue birds around and several (fat) lizards. There are 2 chrysalises I see hanging under the eaves of my house with about 6 more caterpillars looking like they might have found a place to hang in their “J”. Hopefully, in a few weeks I will see some butterflies!

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  3. Just found a bunch on my hammock under my big Chinese Elm in my backyard and on the ground. Does anyone know how long they hang around? I don’t want my dog eating them and/or either of us stepping on them. Thanks!

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  4. I just saved at least 50 from ravenous birds!! Already in pray position! They do well with egg crates and a giant cookie jar with Chinese tree leaves! They marched from one end of my yard to the other ” wondering” with purpose! They ate my tree!!

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  5. We have been doing the Bugs In Our Schoolyard program at our Boys & Girls Club (JAMS Clubhouse) in Santa Monica. We found 2 of these caterpillars marching across our patio. We were so amazed to see them! Very cool.

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  6. Today after 15 days of careful watch every mourning cloak butterfly emerged from there amazing transformation ! I fed them some rotted watermelon , they basked in the warm sun for a couple hours. We said our goodbyes! They seemed to float happily with every gust of wind . One by one . Then there were none . These little guys for the record do not eat your garden flowers! Amazing !

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    • Thanks for providing your wonderful experience with Mourning Cloak butterflies. You can continue to put rotting fruit in your garden to provide them with food.

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    • Mourning Cloak Caterpillars are not deadly poisonous, though if you had that concern, you should have sought medical advice rather than an internet web site. Local irritation may occur as the site of a sting.

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  7. Today (Saturday) I noticed about 20 of these guys under the eaves of my house. Some are hanging in a J and some are still laying flat. A few were still crawling up the wall toward the others, presumably to find their spot. Super cool. The only problem is that on Monday morning there will be painters coming to power wash my house and repaint! I’ll have to move them tomorrow (Sunday). I’ve just read about how to move them as chrysalis but can I move them as a J? Will I totally mess up their process?

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  8. Just went outside to find about 30 of these guys all over the backyard, our Chinese Elon and the outside and waves of our house. They are huge, and very fast! I have two toddlers and a German shepherd who all love playing in the yard I told them to not touch the caterpillars but these guys are everywhere – are they dangerous if the kids were to accidentally touch one? There are also a group of sparrows going wild in the neighbors yard and I’m assuming they found their caterpillar family -I want to protect the ones in our yard is there anything I can do?

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    • We have read that Mourning Cloak Caterpillars might sting, but to the best of our knowledge, the sting is not dangerous. The caterpillars do have spines which makes it difficult for many predators to eat them

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    • I played with these in the Bay Area in ca in the front yard in early spring we had so many of them I kept them until they transformed into butterflies and played with them daily after school and so did my friends I never had any issues with them and they were a huge part of my childhood every year!

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    • According to BugGuide: “Caution: Do not touch the larva; its spines may cause a stinging sensation if handled. The pupa of the Mourning Cloak is harmless – unlike the pupa of tent caterpillars (Malacosoma species), which may cause an allergic reaction on the skin if handled by allergy sufferers or individuals with very sensitive skin.”

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  9. I have a couple of these on my courtyard, but non of them have opened. They’ve been hanging for more then two weeks, how long does it take for them to transform? Also, I live in southern California and it’s been hot.

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  10. We have two mourning cloak caterpillars that seem ready to pupate but they are not hanging upside down yet. They have been holding on horizontally to under-side of a stick for several days without moving. They are still alive, but I’m wondering if this is normal.

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  11. I found this while working at a house yesterday in Lacrosse, WI. He got dragged into the towel I was using and felt his spines as I was working. He seemed fairly chill. We like to name unusual bugs we find, so this guy is now ‘Goliath’.

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  12. We seem to have several around our home and many are hanging in the chrysalis stage right now. Southern California.

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  13. I just caught morning clock caterpillar I was playing with it for quite a while and then I got some poking me and I was curious why esteemed we thought it was a poisonous but it was figured out that because of my aunt and the website thank you this is very helpful now I know for next time

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  14. We just found hundreds of these caterpillars in our community on a tree. Many of them have died but we saved a couple of dozens by taking them home. They are ready to hang upside down and pupate. So cool! I am very much tempted to handle them but they are scary looking 🙂 my kids and I can’t wait to see the butterflies.

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  15. i found one of these hanging from a concrete wall out by Fountain Valley, California. I wanted to bring it home so my son could see it transform but was afraid if i moved it it would mess up its process. very curious caterpillar.

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