Most Canadian children grow up being read stories about Monarch butterfly caterpillars feeding on Milkweed leaves. They may be surprised when they see a totally different caterpillar chewing steadily away on a Common Milkweed leaf. These other ones are very spiky looking with black and white tufts and a strange colour combination of orange, black and white. They aren’t butterfly caterpillars, though, they are moth caterpillars.
A Milkweed Tussock Moth caterpillar hanging out.
We used to see these caterpillars fairly often when I was growing up but I haven’t noticed them in recent years. Then, while on a guided nature walk at the Riverwood Conservancy in August, one of the participants pointed out two of them eating away at a Common Milkweed plant in the Maintenance Loop.
Be Careful! Don’t Pick Up a Tussock Moth Caterpillar!
Just a word of caution: Many Tussock Moth caterpillars have spines that can cause mild to severe skin irritation if people handle them. It’s best to just observe them from a distance and not risk injury.
What Made These Holes in a Milkweed Leaf?
You can see the type of damage this almost mature caterpillar has made to this leaf.
According to Bugguide, when they are tiny, Milkweed Tussock Moth caterpillars often feed together on the same plant but they usually move away to their own plants as they get near maturity.
Different insects, and insects at different sizes in their life cycles, often make different types of holes in milkweed. Baby monarch caterpillars, for example, usually eat from the underside and often don’t get all the way up through the leaf. Milkweed Beetles often chew pieces out of the edges of leaves.
Hey, Someone Pooped On This Leaf!
One way to spot caterpillars, which often hide underneath leaves while munching, is to look for the “frass.” This pile was deposited by one of these Milkweed Tussock Moth caterpillars while it ate.
Are Milkweed Tussock Moths Large and Showy Like Monarch Butterflies?
Unfortunately, I don’t have a photo of one of these moths. You can see some nice ones online, though, on the Bugguide webpage. The body has some interesting orange, black and white markings but overall the moth is quite plain.
The wingspan, according to Bugguide, is 32-43 mm (or about 1-2 inches.)
Notice the little reddish “feet” add extra colour.
I’ll keep an eye out for the moths now I know that they are around but I’m skeptical whether I will find any. In the meantime, I enjoyed a chance to see an old friend from my childhood.
Related Reading
- How to Sex Monarchs
- Monarchs Sail Across the Lake in September
- Standing Still Watching the Rattray Parade
Join In
Have you seen any of these brightly coloured caterpillars in your neighbourhood? Please share your sighting with a comment.
Unfortunately we found these little boogers eating our Asclepias plant. (orange butterfly flower) Just 7 of them took almost all of the orange blooms from the bush over night! We had never seen them before, but got this new perennial this year. Thank you for the pictures. None of our neighbors had seen this caterpillar before either.
While I’m sure it’s upsetting to see the flowers munched, these moths are just as important in their own way as the Monarchs, even though they are not talked about as much. So you’ve been helping a native species that also has had problems due to loss of habitat. I’m not sure if Butterfly Milkweed will sprout new flowers but it likely will as Common Milkweed does. Hope so!
I’m so bummed! I have a whole bunch on one plant ( it was a wild weed that grew this year-2021) I purchased the milkweed roots to help Monarchs this year. Not 1 Monarch has been seen, but when I saw that weed full of the caterpillars I was beside myself with joy! Only now to find out they are moths! Yuck!
Sorry they aren’t as showy as Monarchs but they are just as important in the natural world. You may get a Monarch yet, too, as they have several generations of caterpillars each summer.
Be Patient, it can sometimes take a coupe of migration cycles, just keep you milkweed going and keep an eye out. You will be rewarded.
Yes I just did!
Victoria Hall from Bardstown, Ky.
I just walked out on my deck and saw this beautiful creature crawling all around raising
His head up and down looking this way and that way. I took pictures and a little video as I’d never seen one like it. I have a large garden near of veggies and many types of flowers including sunflowers, but I can’t imagine how he got onto the top level of my deck. I’m going to post my photos to your website. I put him in a safe place in the grass.
What a nice surprise!
Sorry for the late reply. Your caterpillar may have been ready to pupate–hope it turned into a great moth for you!
8-11-21. Massachusetts.
On milkweed plant. About 3/4 inch long.
Thanks for sharing!
Wish I could send you a picture…have so many of these little guys on our milkweed leafs. Always thought they were monachs, glad to finally know what they really are. Seem to be doing OK here along the coast of Maine
They are native moths and need our help just like the more colourful Monarchs, so thank you!
Thanks for the photo. I just identified one on my milkweed here in Southern Pennsylvania, USA thanks to your website. She/he is very happily munching away.
Great! With luck this also-getting-uncommon moth will continue to prosper!
I have them on my milkweed plant is SE MN. I have never seen them before today and was glad your site identified them.
In their own way, they are just as nice as Monarchs–thanks for sharing your sighting!
I have one or two here in central VA. Wondered what it was. Last year it ate my roses! This year I have milkweed which it prefers!
Interesting that it would eat roses; that’s the first time I’ve heard of that. Thanks for sharing!
Found quite a few on only one weed in my flower bed in NW Ohio
They do seem to like to stay together. Thanks for sharing!
We have a lot of milkweed around here, close to Belleville, Ontario and we have a lot of these caterpillars. I was wondering if they might be edging out monarch caterpillars. The last couple of years, I can’t find any monarch caterpillars. I still see some butterflies occasionally just not the caterpillars.
I’m glad these are good for plant life but the monarchs are prettier. 😉
Yes, Monarchs are real beauties! I doubt that the Tussock Moths are out-competing the Monarchs as they don’t directly have any way to attack each other. I’d be more suspicious of ants which are known to eat Monarch eggs and some other similar predators. If I understand correctly, the Tussock Moths lay quite a few eggs in one spot so the odds are good that not all will get eaten before they hatch. Monarchs usually dot their eggs only one or two at a time so they have no “safety in numbers.” I hope you get more Monarchs next year, though!
I appreciate the photo and the information
We found a few of them in our east central Minnesota, milkweed, monarch butterfly garden.
Thanks for sharing: they are quite interesting caterpillars!
8/5/2018 North Central Penna. 10:30 AM
Found a bunch of Tussock Moth caterpillars on butterfly weed eating away. Had never seen them before. Thanks for identifying them for me!
Interesting! Be careful if you handle them as some people react badly to their spines. (skin irritation; red eyes; etc.)
We just found a whole bunch of them tonight in our milkweed. Thanks for the info! They are on one side of the property, while the monarchs are munching away on the other side of the yard. We are in Alfred, Ontario.
I wonder which ones will be ready to transform first? Thanks for sharing!
This morning I was coming back from going to the store.i was on a trail and I saw a milkweed tussocks moth caterpillar.this is in Prescott Arizona
Thanks for sharing your sighting of these fuzzy moth caterpillars!
Just found a few within the last few days in Lexington Kentucky
Thanks for sharing your “spiky” sighting!
Spotted one on our acreage connected to Mark Twain National Forest in Missouri.
Sorry for my slow reply. Thanks for sharing your sighting!
I just counted 12 of these caterpillars on my milkweed. First time I’ve seen them on there last year they were full of monarch caterpillars. Thanks for identifying them for me. Tallahassee Florida
Both Monarchs and these moths can be on the same plant so maybe next year you’ll see both!
Orange and black tussock caterpillar in Meredith NY
They seem to be popping up this year! Thanks!
I saw one today at my house but it won’t let me add a picture to share
Sorry there is no way to add photos here. If you’d like, you can try the iNaturalist website or app which lets you upload photos for others to see. Thanks for sharing your sighting though!
I just saw one in my breezeway and some how came into contact with it. It leaves bumps like mosquito bite. They itch also ,interesting looking fellow
Sorry to hear you met one of these a little too closely! I hope the rash clears quickly!
My friend has a numerous amout of these in her yard. She lives in Cherryvale Kansas and too used your site to verify what they were. Cherryvale is located in the extreme southeast area of Ks. near Oklahoma and Missouri.
There are some other spikey caterpillars but if they were on Milkweed they likely were these ones. Just a reminder to readers not to touch spiky caterpillars: some of them have spines that make humans itch or rash.
I just found 5 of them trying to climb my back door…..will carefully move them without touching….thanks for the info.
It’s a good idea to avoid touching them with your bare hands. Strange place to have them invade! I hope they leave your door alone in the future!
Thank you for the information! I have had no monarchs, but I’m glad I could help out these moths. The red milkweed bugs I have seem a bit perplexed by the larvae, but they don’t seem to be bothering them. I have seen stink bugs eating them though.
Interesting! Thanks for the info on the stink bugs!
Just saw one walking across my driveway towards the milkweed I let run a little rampant in my front garden , trying to help out the Monarchs here in Massachusetts
By helping the Monarchs we are helping so many other native creatures–thank you!
First time for me to find these caterpillar on the milkweed plants, I left on the edge of my garden. I live in Connecticut, southeastern area. Moved a couple of them off one weed to the milkweed plant. Thank you for the pictures and information. Grearfully appreciated.
Thanks for helping wildlife with your garden!
I just found 10 of them on my milkweed plant as I was looking for monarch caterpillars! I live in SE Wisconsin. Thanks for your site in helping to identify them. Will they harm the rest of my garden at all? That’s my only concern.
No one I’ve heard from said they’ve done any particular damage to their garden. So I think it will be fine.
I have a bunch that just hatched on my swamp milkweed IN my garden. Albeit a monarch rearing and pollinator garden. 😁🦋🐛
I’m glad there’s room in your garden for these guys as they are often overlooked compared to the showy Monarchs.
Just found hundreds, literally, of these caterpillars on my neighbours milkweed. So many of them, I gave up trying to count them. They totally devoured several big leaves. In Guelph, Ontario, Canada.
Yes, they seem to feed as a group in the early stages probably trying to overwhelm predators (including insect predators that are not affected by milkweed chemicals.)
I’ve found 25 tiny ones and several larger ones on the milkweed in my pollinator garden! Really interesting that they have spines that can make me itch. Will keep my hands off!
I usually use a leaf, twig or piece of paper to handle caterpillars ever since a relative got puffy fingers from a Hickory Tussock Moth cat. And thanks for helping Milkweed Moths–they are not as well known as Monarchs but I think they are just as important, really.
My daughter and I came across a huge MASS of them here in Minnesota when we were out on our run. They were on many milkweed plants more than 30 in huge clusters. If they felt a vibration on the ground or our touch on a leaf they all dropped to the ground!
I’ve heard they feed in large groups, especially when young, but I haven’t been lucky enough to see that. Maybe I bang my feet down too hard–I’ll have to try sneaking up!
Thanks for the information about these caterpillars. Just found a bunch of them on my swamp milkweed and was concerned. I’m in MA.
Although they aren’t as strikingly beautiful as Monarchs, these moths are native, too.
We’ve got a bumper crop of monarch caterpillars on our butterfly weed in SE Wis this year and just found some tussock moth caterpillars alongside the monarch cats this morning. We brought one inside to watch it develop as we do with the monarchs.
I am not sure how soon they turn into moths — same year, or after a winter. I guess you will find out!
I found a lot of these hairy caterpillars on my milkweed plant in Augusta,Maine. I hope that they will not bother the monarch caterpillars.
They both are native and natural so they should be fine together. And the milkweed here seems to re-grow without any problem even if they eat a lot of the leaves.
Quite a few of these in my milkweed. Still plenty of monarchs and black swallowtail butterflies around too although I haven’t seen their caterpillars.
I usually find Monarch caterpillars by accident when taking a photo of something perched on the blossoms. Their markings really are camo! And I didn’t notice the 5 black swallowtail caterpillars in my parsley till the spiky leafless stems made me stop and look more closely. So hopefully you have caterpillars there, just hiding.
Just found one this morning on the milkweed in my garden here in Southwestern Ontario and, like others who have commented, I had no idea what it was. Thanks so much for helping me identify it. I am also very glad to hear it won’t hurt or “push out” the monarch caterpillars! I teach my young students at school all about the monarchs so I will have to show them pictures of and teach them about these moths as well now!
That would be great as the moths are just as important, really, as the Monarchs, just a bit less showy!
I’ve never seen these before yesterday when scouting around my property. I found 14 of them clustered on one leaf! I’m in Northern Michigan and I’ve heard they’ve been causing a lot of damage this year. (I don’t know what they’ve damaged….just that someone’s family member told them that.) I was going to dispose of them but now you have me rethinking it. I also read that they can poison birds because of the milkweed they eat. Can you expand on this? Thanks!
They don’t really poison birds (enough to kill them) they just taste awful and can upset their digestion, so they learn to skip them the next time. They do it by collecting a harmful chemical from milkweed sap in their bodies when they eat the plant. Some people are upset to see the moths eating the milkweed but it doesn’t really harm the Monarchs. Both have lived together for 1000s of years with no ill effects.
I just found one on a milkweed plant in my garden in West Michigan. It was about an inch long. I have never seen one before.
Sounds like one that may be turning into a moth soon! We used to see them as kids all the time but they don’t seem as common now.
I just noticed several near my (former) milkweed patch in Southern Maine. I had so many monarch caterpillars this year that the patch is now a leafless collection of stalks! I wonder if this moth eats anything else? Thank you for the information!
I believe it does eat some other plants. BugGuide.net reports it can feed on Dogbanes. https://bugguide.net/node/view/433 There may be some other related plants it enjoys.
Just planted milkweed this year in Boonsboro Maryland and these little buggers moved in and made themselves at home!
Yes, the benefit of growing milkweed is all of our native critters get a better chance to survive. Thanks for helping them! (They can share with Monarchs.)
I have them in Traverse City, MI
I’m a bit jealous that so many readers get both kinds of caterpillars. So far I’ve only had Monarchs.
Just found four of them in Rural Retreat, Virginia.
I’ll keep two of them inside to see the moth they’ll be. Thanks for the info.
Hopefully they will grow to maturity, that would be an interesting moth to watch emerge. A huge number of caterpillars die from things though–which I guess is just as well or we might be over-run!
I have not seen one of these caterpillars before today. It’s crawling on my front porch railing. I’m located in the southern tier of Western New York.
It may have been a grown one on its way to hide to change into a moth. Thanks for sharing!
I have a front field full of milkweed, and there are lots of these tussock moth caterpillars on the plants. There are also many monarch caterpillars (I just counted 8 on a quick walk through), so that is wonderful. I live in southern Maine and spread the milk weed seeds when the pods split open.
What a wonderful field to explore! Thanks for sharing the images of munching caterpillars and seeds drifting on the breeze!
Yes the tussocks like to stick together. They attsck a leaf until there is nothing but the skeleton of the leaf they r chewing on
Sounds like a “herd” of Tussocks has been nibbling near you!
Just saw tussock Caterpillar eating away at my milkweed. I live in innisfil Ontario. I also had lots of monarchs and even some of their Caterpillars back in June. There are still butterflies and hopefully moths coming soon.
Yes, we have another batch of Monarchs due to hatch out soon, too. I think they will be the ones that migrate. (I don’t bring them inside; I just watch them on my walks.)
Just spotted these this morning on my milkweed in Ottawa, Canada. I’ve never seen them before.
Sorry for my slow reply. Thanks for sharing your sighting! I think they may be having a good year, judging by the number of sightings.
I had 2 egg masses on 2 milkweeds this summer. One disappeared but I suspect they are living in the tall grasses that I have nearby that milkweed. The other was on a large milkweed next to my house, so it’s been easy to see their growth. I brought several inside to see what’s happening with them. They have shed skins and are now quite large. Looking forward to seeing what they do next. I did see a picture of the moth, which is not one of the prettiest, rather plain, I’d say.
Sorry for my slow reply. Thanks for sharing your caterpillars. The moths are rather simply coloured but their young sure show up!
Just found some of these tussock caterpillars in my Charlottesville VA garden – have not seen them before.
Sorry for my slow reply. Thanks for sharing your sighting! I think they are having a “good” year judging by the sightings.
Just saw these moths eating the milkweed in Waterford, Michigan. Crazy to see how much of the plants are gone! Do they hatch from a yellow type egg on the pod of the milkweed?
Sorry for my slow reply. BugGuide mentions the eggs are usually laid in groups, but not what the colour is or the location. https://bugguide.net/node/view/433
They are yellowish though https://bugguide.net/node/view/1545151/bgimage
I hope this helps a bit.
Do they have a smell to them?
Sorry for my slow reply. I really don’t know, sorry!
We have a lot of these on the milkweeds in our side yard… Western hills of Maine
Sorry for my slow reply. Thanks for sharing your sighting–its seems like they are having a good year!
Well, i have had 1000’s of them along side the monarchs all eating my large native crop of milkweed and more.
Lake Simcoe, Oro Beach area.
I was going to post picture of a large grouping of 20 plus but no area i see to do that.
Sorry for my slow reply. Thanks for sharing your sighting. Unfortunately there is no way to share photos here. You may want to add the photo to iNaturalist.org though?
I have about a dozen on one leaf. Top and bottom. Never seen them before. I had one baby monarch caterpillar but it disappeared. I hope they don’t migrate to my two baby plants because it will destroy them. One is about 4″ tall and the other about two.
Sorry for my slow reply. Thanks for sharing your sighting! Although these moths can eat all of the leaves off a milkweed, it is very unlikely to kill the plant. Hopefully they left your young plants alone!
We’ve been leaving a patch of milkweed in our garden for the past few years for the monarch butterfly. This year has been amazing. At one point we counted over 40 monarch caterpillars and 19 chrysalis. We still have a few chrysalis but haven’t seen any of their caterpillars around. Now we have piles of the tussock caterpillars that I’ve identified from your site chewing away on my milkweed. I enjoy having my yard full of life.
Thanks for the post
Sorry for my slow reply. Thanks for sharing your sightings! Yes, your garden is helping a LOT of native insects: Milkweed is a source of nectar for many, many other butterflies and moths too.
I saw one at the lodge in northern Arizona, mistaking it for a wooly bear catipillar I picked him up , no skin irritation but then I saw this article and set him safely on an oak plant , I guess I was lucky to get no irritation from the interaction but it was a really cool experience.
Glad you didn’t get irritated. They are really pretty cats!
Just found two of them on our milkweed, had to take a picture and look them up..found on your site…thanks they are beautiful but, I don’t tough anything Unless I know about them…
Sorry for my slow reply. Thanks for sharing your sighting! It’s a good strategy not to handle unknown insects. Some, like Blister Beetles, can be quite harmful.
seeing them for the first time in Western Illinois, as Fall begins!
Sorry for my slow reply. Thanks for sharing your sighting! I think they must be having a “good” year!
They are here in Shannonville Ontario.. chomping away at the milkweed….very strange habit of doing this shakey kinda dance if they are disturbed
Interesting! Possibly to startle and scare away predators?
Found this little one on the milkweed in my garden. We have raised and released 7 monarchs this summer. 6 male 1 female. Can we raise this Tussock catipiller the same way?
If I understand what I’m reading correctly, they will pupate and not hatch out as the moths until the following spring. So it may be easier just to let them find a spot to rest for the winter by themselves. Thanks for sharing your sighting, and your great success with Monarchs.
I just seen one of these today it was sitting on the screen of my porch. I’m normally an insectiphobe but caterpillars for some reason don’t set me off always had a soft spot for the little guys
I always laugh at myself for liking butterflies but then wondering why my garden plants keep getting eaten by caterpillars. Glad you got to see one of these cute moth caterpillars!
Just found your site. At least a dozen tussock caterpillars on common milkweed here in northeastern Illinois
Sounds like they are thriving, which is a good thing!
We discovered these on the underside of a leaf last night. This morning their orange coloring has appeared and most of the plant has been eaten. We are in update NY.
They are native, so you’re helping them to “eat local” ! thanks for sharing!
These little guys have destroyed a whole plant at my house in northwest ohio. There were about 30 of them on one plant
While they can eat all of the leaves off, usually milkweed with survive and grow new leaves either later in the summer or the next year. To me, helping these moths is just as important as helping Monarchs, even if they are less showy. So thank you for hosting them!
Just found 5 of these in a new pollinator garden in Lancaster PA at a non profit. We just put the plants in this past Msy. Thanks for all the info on the Tussock Moth caterpillar. I had no idea what they were.. We also have 7 monarch caterpillars. They are all sharing our butterfly weed plants. I hope there is enough to go around because the plants have been chomped down.
Sorry for the belated reply. I do hope both your moths and butterflies were able to flourish!
Have found four on the remains of my milkweed on a cold 9/19/2020 day in SE Wisconsin. So pretty!
Sorry for the late reply: I’m glad you were able to enjoy seeing another of our native creatures.
I think I just found one, first time ever, in my driveway. Still alive.
If it’s fairly large, it may be ready to pupate and on the move looking for a safe place to start the change. Thanks for sharing!
I have them on the common milkweed but not on the swamp milkweed.
Here is a photo.
https://pbase.com/mperry/image/172800890
Good to know they eat Swamp Milkweed too– Thanks for sharing and your photo is much better than mine!
Hello, I saw a milkweed tussock moth caterpillar yesterday in Iowa City, Iowa on a milkweed plant in Hickory Hill Park. Thanks for your post, which enabled me to identify it!
Sorry for the slow reply–glad you found some of these fun caterpillars!
Just saw a couple today in Merrickville Ontario on my front veranda and milkweed.
Sorry for the slow reply–I’m glad you’re “hosting” a few on your milkweed! They are quite a nice caterpillar to look at.
Been seeing a bunch of Tussock Moth caterpillars eating my milkweed plants leaves. Thanks for identifying them for me and that they are good for nature. I was concerned if they were harmfu. Would they keep Monarch caterpillars from eating the plants.?
Sorry for the slow reply–they don’t seem to stop the Monarch caterpillars, at least not on the plants around here. Both have lived together for so long I think they manage well together.
My husband just found groups on two chewed milkweed plants. Several years ago, we had a dozen or so Monach caterpillars, crystalline, and butterflies on our milkweed, but none since. We were very surprised to see these little visitors. We are in central Ohio. Thank you for helping me identify the Milkweed Tussock caterpillars.
In my neighbourhood many people have added some Common Milkweed to their yards. Monarch caterpillars are only found on a few plants though. And we never get the tussock moth caterpillars. I’m glad you’ve had both native species on your plants!
On common milkweed by our driveway, in Sharon, MA
Thank you for sharing!
Saw one of the Milkweed Tussock Moth caterpillar while out walking with my grandsons. Didn’t know what kind it was but my grandson said take a picture. So I did and found it on your site. I will try to send a picture but …
August 22 2023
I’m glad your family got to see some of these moths’ caterpillars–they aren’t as well known as Monarchs but they are native and important, too!
Just identified these thanks to your website! North Alabama on my milkweed that never blooms. They are very pretty.
On behalf of the moths and critters that need milkweed, thank you for growing it!
I have been inundated with these caterpillars. Was searching to see what they are as they are devastating the milkweed I leave for the monarchs. I’m in Barre Vermont in the last few days of July.
Luckily these native moths are just as deserving of your care as the Monarchs, so hopefully you won’t mind them eating your plants. One thing I have noticed at a park near me is that the Monarchs like to lay their eggs on the new milkweed shoots coming up from the roots after they have been mown down. So probably Monarchs will prefer the new shoots coming up after the moths have eaten down some of the stems.