Stinging Caterpillar: All You Need to Know for Safe Encounters

Stinging caterpillars are an intriguing yet often misunderstood group of insects, capable of causing painful reactions in humans. Getting to know these fascinating creatures is essential for both gardeners and nature enthusiasts alike. In this article, we’ll help you better understand the stinging caterpillar, its life cycle, and how to handle potential encounters.

Many stinging caterpillars come in vibrant colors and interesting shapes, making them a captivating sight. Upon closer look, you’ll notice that they’re covered with hair-like structures called setae, which are responsible for their notorious stings. When touched, setae can break off and release a venom that causes itching, burning, or even more severe reactions in some people.

It’s important to remember that stinging caterpillars play a vital role in the ecosystem, with some even serving as a natural form of pest control in agriculture. As you continue to explore the intriguing world of these caterpillars, always approach with caution and respect to avoid any potentially painful encounters.

Understanding Stinging Caterpillars

Stinging caterpillars are a unique group of larvae that possess venomous spines or bristles. When you accidentally touch or brush against them, it can cause painful skin reactions. In this section, you’ll learn some important characteristics and types of these fascinating creatures.

These caterpillars come in various colors, often bright red or yellow, which serve as a warning to potential predators. The spines or stinging hairs are usually present on their backs, offering them protection. Some common stinging caterpillars include the spiny oak slug, flannel moth, buck moth, puss caterpillar, saddleback caterpillar, io moth, and fuzzy caterpillars.

Here’s a comparison table to help you understand the differences between these caterpillars:

Keep in mind a few safety tips when encountering stinging caterpillars:

• Avoid handling them directly with your bare hands.
• Be careful when working in the garden, especially near plants that attract these caterpillars.
• In case of an accidental sting, wash the affected area with soap and water, and apply a cold compress to reduce swelling.

Remember, stinging caterpillars play a crucial role in the ecosystem, so it’s essential to admire these intriguing creatures from a distance and treat them with respect.

Identifying Stinging Caterpillars

When identifying stinging caterpillars, pay attention to their colors and appearance. Most of them have bright, vivid colors and fuzzy textures.

Common stinging caterpillars include:

• Puss caterpillar: Fuzzy appearance, dark brown to grayish black.
• Buck moth caterpillar: Spiny, black body with red and white stripes.
• Flannel moth caterpillar: Fuzzy, white, yellow, and black with long wispy hairs.
• Io moth caterpillar: Lime-green with bright horn-like spines and stinging hairs.
• Saddleback caterpillar: Green with a brown saddle-like pattern and irritating spines.
• Hickory tussock caterpillar: White and black, with long, wispy hairs.
• White flannel moth caterpillar: Bright yellow with wispy white hairs.
• Spiny oak slug caterpillar: Green or yellow, with rows of spines.
• Stinging rose caterpillar: Brightly-colored, with spine-covered horns.

To help you distinguish between these caterpillars, here’s a comparison table:

Always be careful when encountering caterpillars. If you spot one with bright colors and a fuzzy appearance, it’s best to avoid touching it to prevent possible painful stings.

Common Habitats of Stinging Caterpillars

Stinging caterpillars can be found in various habitats, from forests to gardens, depending on the species. To help you identify their common habitats, let’s consider some of the different trees and locations they prefer.

For instance, the bizarre leaf-like caterpillar can usually be spotted on lower branches of trees such as oak, chestnut, dogwood, sassafras, and ash. They often feed on the undersides of leaves for sustenance.

On the other hand, the Io moth caterpillar thrives in locations like South Carolina, being found most commonly on lime.green in color with bright horn-like spines and four rows of stinging hairs.

Keep in mind the following list of trees that can host stinging caterpillars:

• Oak
• Hickory
• Apple
• Cherry
• Maple
• Dogwood
• Poplar
• Bayberry

Stinging caterpillars can also be found in other states, such as Texas and Florida. In Texas, the southern flannel moth or puss moth caterpillar, Megalopyge opercularis, known as “asps,” can commonly infest shade trees and shrubbery around homes, schools, and parks.

Now that you’ve learned about the preferred habitats of stinging caterpillars, be cautious around these trees and locations, and always observe from a safe distance. Remember, stinging caterpillars can cause discomfort or allergic reactions, so it’s best to admire their beauty without getting too close.

Behavior and Defensive Mechanisms

Stinging caterpillars, as the name suggests, have developed a unique way of protecting themselves. Their defense mechanisms involve stinging, toxins, and irritating venom. Let’s explore these features in more detail.

Caterpillar stings are primarily a result of contact with their poisonous spines. These spines have toxins that can cause a range of reactions, including:

• Swelling
• Rash
• Blistering
• Itching
• Nausea
• Headache

Reactions to a caterpillar sting depend on the individual and their sensitivity to the toxin. In some cases, severe allergic reactions may occur, which require medical attention.

It’s important to remember that not all stinging caterpillars carry the same venomous properties. For instance, the spiny elm caterpillar is known to produce mild skin reactions when touched.

When you come across stinging caterpillars, it’s best to avoid touching them. Observe their interesting behaviors from a safe distance and appreciate their unique defense mechanisms. Remember to be careful while exploring your surroundings and stay clear of these fascinating yet potentially harmful creatures.

Treatment of Stinging Caterpillar Exposure

If you experience a caterpillar sting, it’s essential to know how to treat it. Here are some steps to take:

1. Remove the stinging hairs: Use a piece of tape to gently lift away any stinging hairs from your skin. Press the tape onto the affected area, then carefully pull it off, repeating as needed.

2. Clean the area: Wash the sting site with soap and water to remove any remaining hairs or irritants.

Some home remedies can help alleviate the symptoms:

• Baking soda: Mix baking soda with water to create a paste. Apply the paste to the sting site for relief from itching and pain.
• Hydrocortisone cream: Apply an over-the-counter hydrocortisone cream to the affected area to reduce itching and inflammation.

Be aware of potential allergic reactions. Seek medical attention if you experience:

• Swelling
• Rash
• Blistering
• Nausea
• Headache
• Difficulty breathing

Symptoms such as itching, pain, and skin reactions are usually manageable at home. However, if you have a more severe allergic reaction or if your symptoms worsen, consult a healthcare professional.

Preventing Caterpillar Stings

Preventing stinging caterpillar encounters can help protect you from painful reactions. The following friendly tips offer ways to reduce caterpillar stings in your habitat.

Eliminate favorable conditions: Stinging caterpillars are attracted to particular plants. Keep your garden clear of pests by maintaining a clean and healthy environment. Additionally, controlling the population of bugs like slugs and other pests can reduce the risk of stinging caterpillars settling in your garden.

Protective measures: When gardening, wear gloves and long sleeves to prevent direct skin contact with any caterpillars. Taping the cuffs to your gloves can create a barrier for these stinging insects.

Pesticides and Non-Selective Treatments: When necessary, you can use a pesticide like Bacillus thuringiensis var. kurstaki (BTK) to control caterpillar populations. Keep in mind that applying non-selective treatments can also kill non-stinging caterpillars, which are a vital food source for birds.

In conclusion, being proactive with prevention methods and maintaining a healthy garden environment helps you avoid painful stinging caterpillar encounters.

Connection between Caterpillars and Butterflies or Moths

Caterpillars are the larval stage of both butterflies and moths, which belong to the insect order Lepidoptera. In this stage, their primary purpose is to eat and grow, preparing for their eventual transformation into their adult forms. Some common stinging caterpillars include the buck moth, flannel moth, puss moth, and io moth. Their stinging hairs can cause irritation or pain to humans who accidentally touch them.

You might wonder why some caterpillars have stinging hairs. Well, it’s mainly for their defense against predators. These hairs contain venom that can deter birds, lizards, and other predators from feasting on the caterpillars.

Here’s a brief comparison of key features of some stinging caterpillars:

While these stinging caterpillars might seem scary, remember that they eventually transform into beautiful butterflies and moths. For example, the mourning cloak butterfly, which is not a stinging caterpillar, belongs to the same order as our stinging caterpillar friends.

To sum it up, caterpillars are the larval stage of both butterflies and moths. Some of them, like the buck moth, flannel moth, puss moth, and io moth, possess stinging hairs for defense. These caterpillars undergo a miraculous transformation to beautify our world as adult butterflies and moths, serving their role in the ecosystem despite their painful defenses.

Interesting Stinging Caterpillar Species

You might be fascinated by some of the unique and intriguing species of stinging caterpillars. Let’s explore a few notable ones:

Automeris io is a beautiful moth that has a distinct appearance with colorful eyespots on its wings. The caterpillar stage has venomous spines that can cause painful reactions upon contact. Be cautious around these creatures!

Megalopyge opercularis, also known as the puss caterpillar, has a deceivingly soft appearance, resembling a small tuft of fur. However, its venomous spines are hidden beneath the fur and can cause severe pain upon contact.

Parasa indetermina, or the stinging rose caterpillar, displays an impressive array of spine-covered “horns” and spiny bumps along its sides. Despite its small size, this caterpillar can deliver an intense sting that’s difficult to ignore.

Euclea delphinii, commonly known as the spine oak slug, feeds on a variety of woody plants like oak, willow, and cherry species. Its sting is milder than other stinging caterpillars, but it can still cause pain, redness, and inflammation.

Now, let’s take a look at a comparison table with some of their characteristics:

In conclusion:

• Be extra cautious around stinging caterpillars.
• Some caterpillars, like the puss caterpillar and the stinging rose caterpillar, are both beautiful and potentially dangerous.
• Avoid touching any caterpillar with spines or hairs, as they could potentially be venomous.

Remember to stay safe and respectful of these incredible creatures, and enjoy observing them from a distance!

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Tawny Coster Caterpillar from Singapore

Subject: Sting from below caterpillar
Location: Singapore
December 13, 2013 7:27 am
Hi there, wonder if you can help. Got stung on the finger by photographed caterpillar as I was touching it (now I know I shouldn’t).
Felt the sting at that moment though I’m not seeing any welts for past six hours.
Any course for worry? Can you identify this species and is this poisonous?
Hope to get your email reply.
Best,
Signature: Nicky

Dear Nicky,
We believe this is the caterpillar of a Brush Footed Butterfly.  It looks very similar to some North American Caterpillars like the Questionmark and the Mourning Cloak.  We will try to contact Keith Wolfe to see if he is able to identify your caterpillar to the species level.  While a stinging sensation may occur upon contact with the spines, to the best of our knowledge, there are no lasting effects.

Keith Wolfe identifies the Tawny Coster Caterpillar
Hello Nicky and Daniel,
This is a Tawny Coster (Acraea violae) caterpillar, a butterfly that only recently became established in Singapore (http://butterflycircle.blogspot.com/2008/03/voyage-of-tawny-coster.html).  Nicky, I’d wager that what you felt was a prick from a sharp spine and NOT a poisonous sting, for though these caterpillars feed on a family of toxic plants (Passifloraceae; additional photos/info — http://butterflycircle.blogspot.com/2013/02/life-history-of-tawny-coster.html), they’re essentially harmless to touch, at least in my hands-on experience.  Of course, the outcome could be different if a person is allergic or sensitive to such contact or decided to eat one (as a bird would) for breakfast.
Best wishes,
Keith

Dear Daniel and Keith,
Thanks for your prompt replies. Bingo on the caterpilla – what a beauty it will transform into.
Cheers,
Nicky

Letter 2 – Stinging Flannel Moth Caterpillar from Mexico

Venomous Mexican Stinging Caterpillar
Sun, Feb 15, 2009 at 9:29 AM
I am wondering if anyone knows what sort of caterpillar this might be? It was about 1″ long, a creamy light green color, and was covered with very long dark brown hairs. It was originally much fatter than shown in the photo – by the time the photo was taken, it had dehydrated a bit due to being carrying around in a plastic bag trying to get it identified. Unfortunately I just had a very nasty encounter with one of these, in in the Yucatan peninsula of Mexico (Isla Mujeres – just off the coast by Cancun). It dropped out of a tree and stung me on the leg. It immediately felt like the burn of a bee sting but rapidly progressed beyond this. Caused a large welt and redness and swelling of sting area about 6″ around. But the worst part was the systemic effects of the sting which were horrible (incredible back muscle spasms, tremendous abdominal pain, and intense nausea) such that I ended up in the emergency room. Have looked on the internet to try to find out what it was, but have also been unsuccessful in determining this. Even the locals there couldn’t tell us although most knew that it was very painful and to be avoided at all costs. Any entomologists out there looking for a challenge??? Would sure love to know what this nasty little bug was…
Thanks.
Yvonne
Isla Mujeres, Quintana Roo, Mexico (Yucatan Peninsula)

Hi Yvonne,
We haven’t the time to research this at the moment, but perhaps a reader can provide the answer. We don’t believe this is a Stinging Slug Caterpillar in the family Limacodidae because they don’t generally have hair. We really hope to properly identify this specimen for you and add your public service message to our archives.

Update: Eric Eaton contacted Doug Yanega who provided the following ID:
Tuesday, February 17, 2009
That’s the larva of a Megalopygid, probably a Megalopyge species near
M. lanata
(http://farm3.static.flickr.com/2322/2198568598_0ceb4ee7b6.jpg?v=0).
The long hairs are not the stinging hairs; the stinging hairs are
short, arranged along the side of the body not far above the prolegs.
Peace,
Doug Yanega
Dept. of Entomology
Entomology Research Museum
Univ. of California, Riverside, CA

I was curious, so I asked around.
could use an identification and maybe some warnings, given that Spring Break is about to happen. The critter looks pretty tame, actually, not spiny like you tend to associate with venomous ‘pillars.
Please credit Doug with this. Thanks. Eric.

Ed. Note: Moths in the family Megalopygidae are known as Flannel Moths and the Caterpillars are sometimes called Asps because of the sting, or Puss Caterpillars.

Update:
Tuesday, February 17, 2009
Hi Daniel:
This looks like the caterpillar of the Flannel Moth Megalopyge lanata (family Megalopygidae). It has appeared on WTB before (Unknown Panamanian Caterpillar on Cashew Tree – April 5th, 2008) and a lot of good information was given in response to that post. It is widespread throughout Central and South America and is definitely a creature to be wary of. Regards.
Karl
http://janzen.sas.upenn.edu/Wadults/resultsallphoto.lasso?photocode%20dotj=DHJ55680.j
2008/04/05/unknown-panamanian-caterpillar-on-cashew-tree-is-megalopyge-lanata/Hi

Hi
Thanks for the info! Indeed, the photo noted below is a dead ringer for the
guy that stung me.
I have put a link to your website on an information site for the island,
just so that others can be aware and give a wide berth to this nasty little
bug!
Thanks for all your help
Sincerely,
Yvonne Hillsden

Update:
Friday, , February 20, 2009, 3:21 PM
Saw the post about the stinging caterpillar earlier in the week. the systemic symptoms sounded familiar to something I had come across recently. You may or may not want to share the attached pdf (cmaj-death-from-caterpillar ) with Ms. Hillsden.
Regards,
Jeffrey B. Tucker, B.C. E.
Entomology Associates, Inc.
Houston, Texas

Update: Sun, Feb 22, 2009 at 10:07 AM
Hi Daniel,
Thanks for the heads up.  I had read the CMAJ article already (just after I had been stung actually) and frankly it had scared the crap out of me!  That was one of the reasons why I was so anxious to have my particular culprit identified.  I was very relieved when the entomologist from CA identified my guy as a flannel/puss moth sp.  Would definitely not have been happy to hear that it was a type of lonomia!
Who’d ever think these cute little furry guys could pack such a nasty punch!
Yvonne

Letter 3 – Stinging Flannel Moth Caterpillar from Panama locally called Shinney

Subject:  Catepillar
Geographic location of the bug:  Taboga Island, off the coast of Panama
Date: 09/22/2017
Time: 08:49 AM EDT
This specimen was photographed at my parent’s property. I know it is a moth of some type; however, I have searched unsuccessfully for a photograph of an adult specimen to inlude identification.
How you want your letter signed:  Nature Enthusiast

Dear Nature Enthusiast,
This is a stinging Flannel Moth Caterpillar, Megalopyge lanata, and it should be handled with extreme caution.  According to an article on Research Gate:  “Shinney is a colloquial term used to describe a hairy caterpillar in Trinidad and Tobago. There have been at least four instances in 2010 in which people were envenomated by shinneys in the Bon Accord region of Tobago.”

This was not Tobago it was Taboga, Panamá, one of the many islands off the coast of Panamá; but, considered part of the country.
I am sure your identification still remains the same.
Thanks!  I will look it up now to find an adult species.  Lots of stinging catepillars in Panamá!

We did catch the difference, however, they are in the same general vicinity and insects don’t respect national boundaries anyways.  Here is a Google Maps image of the area.

I knew that!!  🙂  I had sent those pictures elsewhere and was not satisfied with their identification.
I am confident with yours and quick too!  You certainly know your insects!!
Thanks Again!!

But we didn’t and now we and our readers know the difference and distance between the two islands with transposed letters.

Letter 4 – Stinging Silkmoth Caterpillar from Panama: Automeris metzli

Panama Caterpillar ID
Location: Panama – Comarca Ngabe-Bugle area
August 2, 2011 9:50 pm
Hi. Was visitng niece in Panama recently and found this caterpillar in her house (thatched hut). She discovered it when she inadvertently brushed it with her hand and ended up with several hairy pines left behind. Beautiful caterpillar but is it poisonous?
Signature: Nancy

Hi Nancy,
We recognized your caterpillar as one of the stinging larvae in the genus Automeris, a group that includes the North American Io Moth, and we discovered on the private website, the World’s Largest Saturniidae Site, that is is Automeris metzli.  We then found a matching photo on this unusual website.  We advise folks to turn down the volume before clicking the link.  The Bug Paradise gallery has images of the adult and caterpillar.  Caterpillars in this genus have stinging spines and they should be handled with caution.

Letter 5 – Stinging Caterpillar from Mexico

Subject: Burning Caterpillar
Location: Tlaxcala, Mexico
February 12, 2014 9:57 am
We recently moved to Central Mexico (state of Tlaxcala) and my SIL who is a Mexican national brought in this caterpillar and advised me to tell my children that they were not to play with it as it causing a burning sensation when the hairs on the back are touched. Living in the US, we always played with caterpillars so this spiked my curiousity.
Signature: Krystal L (ArmyMustang)

Hi Krystal,
Many caterpillars have utricating hairs that come off when they are handled and these hairs may cause irritation in sensitive individuals.  Tussock Moth Caterpillars fall into that group and this appears to be a Tussock Moth Caterpillar.  BugGuide provides this information on the White Marked Tussock Moth Caterpillar:  “CAUTION: Avoid handling the caterpillar, as its hair is known to cause allergic reactions, especially in areas of the body with sensitive skin (e.g. back, stomach, inner arms). Seek medical treatment if a severe reaction occurs.”  Though it is not your species, your individual might be closely related.  Perhaps your SIL is being overly cautious as there are other caterpillars in Mexico that can cause severe reactions like this Mexican Flannel Moth Caterpillar.

Letter 6 – Unidentified Stinging Caterpillar from Singapore

Unknown Caterpillar
October 4, 2009
Hello bugman,
when cutting our Chamaedorea elegans, my husband felt a burning sensation to his arm. Obviously he touched two of this caterpillars, sitting on a leaf.
I searched your database, but couldn’t find a similar picture. Looks like a stinging slug caterpillar for me.
Thanks for your help,
Best regard
Claudia
Singapore

Hi Claudia,
We are not certain that this is a Stinging Slug Caterpillar.  It looks more to us like one of the Stinging Caterpillars in the subfamily Hemileucinae of the Giant Silkworm Family Saturniidae.  We will try to get a second opinion.

Letter 7 – Stinging Caterpillar from Honduras: Periphoba arcaei

Subject: Almost killed me. Island of Utila
Location: Isla de Utila, Honduras,
October 7, 2013 10:39 am
Hi! This caterpillar almost killed me. I’ve never been allergic to anything, but the poison (acid/whatever) that this thing secretes sent me into anaphylactic shock. We live on the island of Utila in the Caribbean 22 miles north of the Honduran mainland. This bugger fell on me and attached itself to my shirt, then to my skin. It had to be ”ripped off” of my skin where it was sticking to me through my shirt. Intense pain, despite massive pain killers at the clinic, abated only after 18 hours when the swelling burst releasing about a cup of fluid. We have tried to ”find” this thing online and the closest we’ve come to is an Automeris io (Fabricius) , but his guy has little javelin like spears along its side at the bottom. ”Old Islanders” here say it can kill a child, but is seldom seen and only after large storms that come from the north. Any ideas on this caterpillar or can you direct us to somewhere else that might have mor e on them, please and thank you?
Signature: Tony OnUtila

Dear Tony,
Thanks for sending us your photos and location.  We believe you have correctly identified the genus Automeris for this stinging caterpillar and it does resemble the Caterpillar of the North American Io Moth, but there are many tropical species.  We will contact Bill Oehlke to try to determine the species.  This genus is well known for the stinging capabilities of the caterpillars, but your reaction sounds extreme and you are probably correct that there was an allergic reaction to the sting.

What you have identified as fangs are actually spines and it appears the final pair of prolegs are grasping the pen in the photo.

Good Morning Daniel,
Thank you kindly for responding to our e-mail regarding the (almost) killer caterpillar; it is greatly appreciated, especially in light of your limited time to address such inquiries.
I, too, have to assume that the reaction I had was a severe allergic one. That swelling that is evident in the photo continued for hours and resembled the top half of a loaf of bread before it finally burst. For the sake of information, The Lovely Jo had me pop a benadryl tablet immediately and that is what allowed to me make it to the clinic where I was treated for about 3 hours before being released to return to my home. (after the swelling in my throat was diminished and the medications were in force).
Those little javelin/spear/spiky things along the bottom of the killer caterpillar are what most confused us as to an accurate identification, and we appreciate that you have additional resources that you can go to for further information. With our storm season upon us, we could conceivably see these things again.
As a note to file, our gardener had one of these fall on him a couple of days after my unfortunate episode (from the same palm tree by the pool in my front yard) and he also had a reaction. Not nearly as bad as the one I had, but it was on his arm for only seconds, as opposed to the over a minute that one was on my back/side.
This is one killer caterpillar…
Again, thank you for your time and we appreciate all of the information that you can share with us. We pass it on here on the island so that we can all be aware.
Kindest Regards,
TonyP

Hi Tony,
Bill Oehlke provided us with the following identification.

Bill Oehlke responds with Correction:  Periphoba arcaei
Daniel,
I am pretty sure it is Periphoba arcaei in same Saturniidae subfamily:
Hemileucinae, as Automeris.

Letter 8 – Stinging Caterpillar from Guatemala: Automeris metzli

Subject: What the heck is this thing?
Location: Rio Dulce, Guatemala
May 19, 2012 7:20 pm
This little thing was crawling across a pier in Guatemala. Being European, I have NO idea what this could be. Do you?
Signature: Kjetil

Dear Kjetil,
We immediately recognized this as one of the stinging caterpillars in the genus Automeris, but we needed to research the species on the World’s Largest Saturniidae Site where we believe we identified it as Automeris metzli.  Cross checking that name brought us to our own archive.  Caterpillars from this genus have stinging spines and an unfortunate encounter can cause a very bad reaction in some people.  The adult moth pictured on Bug Paradise is quite beautiful.  We are going to copy Bill Oehlke on our response.  He can verify the identification and he might also request permission to post your photos to his website.

Letter 9 – Three Stinging Caterpillars from Uganda

Subject: Ugandan Rainforest Caterpillars
Location: Budongo Forest Reserve, Uganda
March 18, 2013 9:11 am
Hi guys,
We work in the Budongo Forest Reserve in northwest Uganda (on the edge of the rift valley). These three chaps have all at some time in the past been responsible for some pretty nasty stings in the forest (the gummi-bear looking green chap in particular!), but they’re all so pretty we had to forgive them – do you have any idea what they might be? They’re all between 4-7cm long. Cheers!
Signature: Surfingpigeon

Dear Surfingpigeon,
Stinging Caterpillars can be quite unpleasant and some are even considered dangerous.  The green gummi bear Caterpillar is a member of the Stinging Slug Caterpillar family Limacodidae in our opinion, but we will need to try to research the species.

  We believe the other two caterpillars might be in the Tussock Moth subfamily  Lymantriinae, many of which have utricating hairs that cause irritation when contact occurs.  We will attempt to do additional research after posting a few more submissions.

Letter 10 – Stinging Flannel Moth Caterpillar from Guyana

Subject: Hairy Catepillar
Location: Berbice, Guyana
February 3, 2014 10:17 am
Found this hairy caterpillar on a garage near mango trees in Berbice, Guyana. The locals said it was very poisonous and said the hairs would cause swelling and a rash. They said those who have touched them need immediate medical attention. Not sure if it was true, but I still kept a safe distance. Could you identify what type of caterpillar this is? Thanks.
Signature: TKozza

Dear TKozza,
The locals were wise to warn you about this stinging Flannel Moth Caterpillar in the genus Megalopyge.  It is our understanding that the sting can be quite debilitating.

Letter 11 – Pink Caterpillar from Peru: Stinging relative of the Io Moth

Pink Caterpillar in Iquitos, Peru
Location: an hour outside Iquitos, Peru
December 20, 2010 3:15 pm
Hello! I just returned from the Amazon jungle where I saw stunningly beautiful butterflies and wonderfully huge spiders. This is the only fellow I could not identify.
Perhaps you could take a crack at what this guy is going to turn into?
Signature: Regards, Sarah

Hi Sarah,
We cannot tell you the name of the incredible looking caterpillar without doing extensive research.  We are going out on a limb and guessing that it is a Saturniid, and that it may be closely related to the North American Io Moth.  If that is the case, then we suspect this fierce looking South American Moth larva might also be a stinging species.  The sting from the Io Moth Caterpillar is reported to be extremely painful.  We will return later to commence the research.

Update
We found a pink spiked caterpillar, Automeris hamata, on the World’s Largest Saturniidae site.  Then we found a photo of Automeris hamata on Blass.com, but it isn’t the pink color of yours.  We will contact Bill Oehlke to see if he can identify this awesome caterpillar

Update with Identification from Karl
December 21, 2010
Hi Daniel and Sarah:
It looks like Dirphia avia (Saturniidae: Hemileucinae), a genus that is closely related to Automeris.   White seems to be the most common color but the caterpillars do come in a wide variety of shades ranging from green to shocking pink. The markings down the middle of the back are distinctive regardless of color (the dash inside the semi-circle reminds me of a power button). The Area de Conservación Guanacaste (AGC) site has an excellent series of photos from Costa Rica. The species is native to Central and South America, and yes, they are a stinging species. Regards.
Karl

Thanks so much Karl.  You are in agreement with Bill Oehlke on this one.

Bill Oehlke Responds, the second time with an Identification
December 21, 2010
Daniel,
The larva looks familiar to me, but I am not sure that it is an Automeris species. It may well have been green a day or so before the image was taken as it may be prepupal.
If you can find the location in Peru, that will greatly reduce the amount of search time required.
Bill Oehlke

Daniel,
I think there is a good chance it is Dirphia avia. I am very interested in making contact with people who live in South American countires as they can be a great resource for finding larvae, rearing them to adulthood and then photographing adults. I can usually readily identify adults, and then larvae can also be identified. So far there are many species in South America whose larvae have not been identified. I just checked Lemaire’s Hemileucinae 2002, and he mentions Dirphia avia larvae turn from greenish white to purplish just prior to spinning.
The black markings are a pretty good match for Dirphia avia. Any chance there are also pictures of a laterl view, hostplant info, date?
All those things can be helpful.
Thanks for thinking of me.
Bill Oehlke

Thanks Bill,
We will forward your identification to Sarah and copy you in the hope that she will be able to provide you with assistance in the future.

Thanks everyone for helping me out on this one!
Unfortunately this fellow was not on a plant or really anywhere near one, he was headed up the wall of the lodge where we were staying, I assume to start spinning as he was quite fat.
I can give a very exacting location however, we were on Km 52.5 of the Iquitos-Nauta road, about a hours drive southeast of Iquitos, Peru. If you follow this link and scroll to the bottom, there is a map of the location: http://www.bluemorphotours.com/index.php?option=com_content&view=article&id=104&Itemid=87
I took the photo two weeks ago today.
The colors are pretty accurate in the photo, he was a bubblegum pink and about 5 inches long.
Let me know if I can help you in any other way.
regards and Happy Holidays!
Sarah

Letter 12 – Stinging Flannel Moth Caterpillar from Honduras

Stinging Caterpillar
Location: Guanaja, Honduras
April 26, 2011 11:14 pm
What is this caterpillar? It has a severe sting.
Signature: ??

Dear ??,
We have posted images of the stinging Flannel Moth Caterpillar, Megalopyge lanata, several times in the past.  We are going to take this opportunity to create a new subcategory for Flannel Moth Caterpillars.  We love that your photo illustrates two different instars of this dangerous caterpillar.

Letter 13 – Stinging Asp

Fuzzy, slow, brown/white
December 6, 2009
We found this little bug on the wall of our entry way. At first we thought it was a mud-dauber hole but then it was in a different spot the next day. It moves extremely slow.
joe
North Texas

Hi Joe,
This is the stinging caterpillar of the Southern Flannel Moth, Megalopyge opercularis, and it is called an Asp.

Letter 14 – Stinging Caterpillar from Belize

caterpillar
Hello, Let me start by saying I love your website. I often pull it up and browse through all the new bugs posted. I found a caterpillar in Belize on a jungle hike. It was in the beginning of July and the little guy, about an inch long, was on the ground. I hope you can identify this caterpillar and tell me what it will turn into. … Thanks-
Amber
SLC, UT

Hi Amber,
Though we don’t know the exact species of your caterpillar, we can tell you it is a Stinging Caterpillar in the family Limacodidae, the Slug Caterpillar Moths.

Letter 15 – White Stemmed Gum Moth Caterpillar: Stinging Caterpillar from Australia

Spitfire Grub?
Location: Canberra
January 25, 2012 9:54 pm
Woud you please identify this bug, found in a dwarf snow gum on 26 January 2012 at 1100.
Signature: Bill Reid

Hi Bill,
After some searching, we determined that your caterpillar is a member of the family Anthelidae.  According to the Encyclopedia of Life:  “a small family of moths restricted to Australia, New Guinea and the adjacent Aru archipelago. At present the family comprises 74 species in 8 genera described from Australia (Edwards and Fairey 1996) and 20 species from new Guinea in one endemic genus and one genus shared with Australia. However, numerous distinct species have already been identified as undescribed in museum collections such as the Australian National Insect Collection (ANIC).”  Some taxonomists consider them to be closely related to the Lappet Moths and Tent Caterpillars.  We eventually identified your caterpillar as Chelepteryx collesi, the White Stemmed Gum Moth on the Butterfly House website where we learned that “This Caterpillar is a great hazard to people climbing Gum trees. Scattered over its skin are tufts of long stiff reddish hairs, which are strong enough to penetrate human skin. When they do, they are very painful, and difficult to remove because they are barbed and brittle.”  Another bit of information from Butterfly House is:  “It is also one of the largest Caterpillars in Australia, growing in length to about 12 cms. Some trees where they may be found most years in Leichhardt are known by local school-children as ‘sausage trees’ because the Caterpillars look from the ground like sausages growing in the trees.”

Hi Daniel
Thank you so much for this information.  I have many friends here and overseas that are interested.
A great service that you provide.
Best wishes
Bill Reid

Letter 16 – Asp: Stinging Caterpillar, not a Tribble!!!

3 bug pix 4 you…pictures for you
I took these pics of a small creature , approximately 1/2 to 5/8 of an inch in length, on August 22, 2004. It was residing on my front screen door about 4 feet above the porch. It was not moving at the time . I do not know what happened to it. Our house is located in Lawrenceville, in north central Georgia,USA. I have no idea what it actually is , so I decided to call it a “Tribble” after a creature in a famous “Star Trek” episode. Can you tell me what kind of creature it is ? Thanks,
Ferd R Hall

Hi Ferd,
This is actually a stinging caterpillar known in the south as an Asp. It is the caterpillar of the Southern Flannel Moth, Megalopyge opercularis, and the caterpillar is also called the Puss Caterpillar because of its resemblance to a cat. We love your comparison to the Tribbles, and that observation may help other readers with their identification. The sting of the Asp is reportedly quite painful.

Letter 17 – Mexican Stinging Caterpillar

Killer catepillar
Any idea what this nasty little critter is? My husband brushed up against these while trimming a tree in our yard on the beach in Mexico. Sent him to emergency room. He said it hurt worse than when he ran over his foot with lawnmower. In severe pain for nearly 48 hours. Thanks for the help.
Diane & Mike Prewett
Darien, GA
Chicxulub, Progreso, Yucatan, Mexico

Hi Diane and Mike,
There are several U.S. sites devoted to stinging caterpillars. We do not recognize your Mexican species, but will try to research a more definite answer.

Letter 18 – Probably Stinging Caterpillar from Madagascar

Caterpillar in Madagaskar
Hallo Bugman,
I read, that you are interested in the animals of Madagaskar. Here ist a picture of a nice caterpillar.
Christian

Hi again Christian,
We suspect this caterpillar will sting if you come into contact with those spines.

Letter 19 – Stinging and Biting Information requested

Just Curious
Location: Huntington, WV
April 5, 2011 9:11 am
Absolutly LOVE the site. I have learned quite a bit about the insect world. I really appreciate what you all do here.
I do have one request. I do have a bad allergy to bee stings and some bug bites, as I’m sure many people do, and was wondering if it was possible to include in the info you provide whether the insect stings or bites? Would really help us with allergies out, especially those of us who play with bugs. LOL
Thanks for your help! And keep up the GREAT work.
Signature: Rick

Hi Rick,
Thanks for your suggestion.  We generally do make a comment if there is a chance that the creature in question might bite a person or if the creature is venomous.  Just try to use our search engine and see how many “stinging caterpillar” entries we have or “toxic milkweed grasshopper” mentions.  In case you are curious, we have 128 matches for “stinging caterpillar” and 25 matches for “toxic milkweed grasshopper”.  We caution readers about carelessly handling Assassin Bugs and we warn our readership that Toe-Biters bite.  We do not sensationalize the possibility of bee or wasp stings because they will not attack humans without provocation. If we could think of one creature we would not want to be bitten by, it would probably be the Red Headed Centipedes found in Texas and Oklahoma.  We are running a photo of the Red Headed Centipede from our archives with your letter.  If the creature doesn’t bite, or if the bite poses no threat, we generally do not address the issue.

Letter 20 – Stinging Asp

caterpillar
My husband and I found this hairy caterpillar crawling along the handrail of the boardwalk at Grand Bay Wetland Education Center near Valdosta, Georgia. It was about 1 1⁄4 inches long with a rusty-orange “mane” on top of its wedge-shaped body, brown hairy sides with a white strip toward the back of each side. It had a narrow, flat, tail-like appendage in back. When I turned it over, it initially formed a ridge along the ventral side, too, so that it was almost diamond shaped. Then it curled into the ball you see on the leaf. I don’t know what it would eat. The trees along that part of the boardwalk are black gum and pond cypress with button bush, various sedges, rushes, and fragrant water lilies beneath.
Phyllis Hiers

Hi Phyllis,
The caterpillar of the Southern Flannel Moth, Megalopyge opercularis, is known as the Puss Caterpillar (referring to its catlike appearance) or Asp (referring to its very very painful sting). They feed on a variety of deciduous tree leaves.

Letter 21 – Stinging Asp

catapiller
Location: northeast alabama
August 7, 2011 7:05 pm
Found this on a wooden rockin chair. It looks like a little ball of fur
Signature: thanks

Handle the stinging Asp with care, or better yet, not at all.  The Asp or Puss Moth Caterpillar is the immature form of the Southern Flannel Moth, and it is one of North America’s stinging caterpillars.  The sting is reported to be quite painful.

Letter 22 – Stinging Asp Caterpillar

looks like a furry slug
Dear bugman,
I brushed against a tree and realized that there was this bug on my shirt. I flicked it off, and then discovered that it had stung my finger. It is about an inch long, brown, and has orange tufts on its back. Can you tell me what it is? I live in the Lowcountry of South Carolina. Attached are 2 pictures of it. Thank You!

The caterpillar of the Southern Flannel Moth, Megalopyge opercularis, is commonly called the Asp because of its sting.

Letter 23 – Stinging Brazilian Caterpillar

Brazilian Caterpillar
Hi there
Just came back from Salvador in Brazil, where I came across this caterpillar (along with about 30 of its friends) on one of the plants. Someone told me there it was known popularly as largata de fogo, but no-one could tell me if it turned into a butterfly or a moth. It was about 5″ long and if you happen to brush against one of its spiny hairs, you really know about it! Have you come across this one before?
Yours
MARC FORDE

Hi Marc,
We don’t recognize your beautiful stinging Caterpillar. We will post it and perhaps someone will identify it.

Update:  August 5, 2012
While trying to clean up some old unidentified postings, we found this image which we believe is one of the stinging caterpillars in the genus Automeris.  We will continue to research this.

Letter 24 – Stinging Caterpillar from Australia: Chinese Junk

Angry litte catapillar
Location: Nth Queensland Australia
February 21, 2011 5:06 am
Gday mate,
was out in the garden and brushed past a tree that this guy was living in. It took about 5 seconds before I felt like I was being branded with a hot iron ( or a million wasps – not sure)
anyway was real curious to find out what kind it was?
Signature: Doug from Downunder

Gday Doug,
You had an unfortunate encounter with a Stinging Slug Caterpillar in the family Limacodidae.  In Australia, the family is known as the Cup Moth family and the caterpillars, many of which can sting, are called Spitfires according to the Brisbane Insect website.  Your particular caterpillar is the Mottled Cup Moth, Doratifera vulnerans, and the caterpillar, according to the Brisbane Insect Website, is called a Chinese Junk:  “because of their shape and their way of moving like ship at sea.”

Letter 25 – Archduke Caterpillar from Borneo (or possibly Black Tipped Archduke Caterpillar)

Christmas Tree Caterpillar
Location: Mulu National Park, Sarawak, Malasia (Borneo)
October 29, 2010 5:59 am
I found this caterpillar in Mulu National Park, Sarawak, Malasia. Do you know the name??
Signature: With regards, Steven Gehner

Dear Steven,
We are posting your awesome image without doing any research as time does not permit it at the moment.  We believe this is a Stinging Caterpillar in the Slug Moth family Limacodidae, but there are also some unusual looking stinging caterpillars in the family Saturniidae and we would not rule out that possibility.

Correction Courtesy of Karl
Hi Daniel and Steven:
It certainly looks like a Limacodid moth caterpillar but it is actually a butterfly in the family Nymphalidae. It reminds me of the Baron (Euthalia sp.) from India posted previously on WTB. This one, however, is in the genus Lexias, probably L. pardalis. It also has a royal common name, the Archduke. There are at least nine other species of Lexias on Borneo, most of which I couldn’t find caterpillar pictures for, but I think this one looks close enough to L. pardalis to call it. Apparently this caterpillar’s menacing appearance is all a bluff – it is perfectly harmless. Regards.  Karl

Thanks Karl,
It really does look identical to the Archduke Caterpillar, Lexias pardalis dirteana, on the link you provided.

Keith Wolfe offers another possibility
Hi Steven and Daniel,
In the interest of scientific accuracy (regrettably, the Internet is full of potentially misleading, and downright wrong, caterpillar identifications that subsequent visitors take as valid and unwittingly perpetuate), please allow me to caution that it’s equally possible for this distinctive young butterfly to be Lexias dirtea, the so-called Black-tipped Archduke.  The two species have virtually identical adults and immatures, which I know firsthand having reared L. dirtea (coincidentally from Borneo) and a number of related taxa.
Best wishes,
Keith Wolfe

Letter 26 – Stinging Caterpillar from China

Subject: Possible Stinging Caterpillar?
Location: Southwestern Shaanxi Province, China
September 12, 2013 1:55 am
Hi Daniel,
I came across this caterpillar on the footpath of the gardens outside our apartment block when I was walking my dogs. I didn’t touch it directly as it looked like it had stinging bristles but I encouraged it onto a leaf and put it onto a bush so it wouldn’t get trodden on (or sting one of my dogs if they saw it and gave it a sniff).
Except for the colouration, it looks superficially similar to the zephyr-eyed silk moth caterpillar pictured on your site so I was wondering if it could possibly be a different kind of silk moth caterpillar?
Signature: Paul UK

Hi Paul,
We agree that this is most likely a stinging Caterpillar, and it is probably in the family Saturniidae which includes the Zephyr-Eyed Silkmoth, however that species has a very limited range in New Mexico and vicinity and the genus it belongs to is strictly new world.  This also looks similar to some Nymphalidae or Brush-Footed Butterfly Caterpillars which includes the Mourning Cloak Caterpillar, but our gut instinct is still a Saturniidae Caterpillar.

Letter 27 – Stinging Caterpillar from the Amazon: Automeris species???

Caterpillar in Amazon
Thu, Feb 19, 2009 at 12:40 PM
Last week of January (rain season), we found this Caterpiller on a tree near a salt water pool in the rainforest of the southern Amazon in Brazil.
The Caterpiller is about 10 cm long. Image 1 shows the full view; image 2 shows the face; image 3 is not the Caterpiller, but a part (flower?) of the tree. It seems the caterpiller is mimicrying.
What, o what kind of caterpiller is this?
Rien Schot
Southern Amazon, Brazil

Hi Rien,
We are posting your image right before leaving for work and haven’t the time to research the species. We are quite certain this is a stinging caterpillar in the genus Automeris, a large genus that includes the North American Io Moth. When we have a chance, we will browse through the World’s Largest Saturniidae Site to see if we can identify the species.

Update:
Fri, Feb 20, 2009 at 10:47 AM
Daniel:
What an interesting run of awesome but dangerous stinging caterpillars!  I think you called it right, it is in the genus Automeris (Saturniidae : Hemileucinae). This is a very large New World genus (150 species and subspecies by one count), so making an absolute identification is very difficult. However, based on appearance and distribution I believe it can be narrowed down to A. egeus or A. larra. Of the two, I think A. egeus is the closer match. Regards.
Karl
http://www.silkmoths.bizland.com/kwaegeus.htm

Thanks for the assistance Karl.  Once a word or term enters the zeitgeist of the world wide web, search engines latch onto it quite quickly.  A few weeks ago we answered and posted quite a few letters from Namibia.

Letter 28 – Stinging Guatemalan Caterpillar: perhaps Leucanella species???

Guatemalan Caterpillar
Hey. Love the site. I took this picture in 2005 in the mountains around Chinique, Guatemala. What was it and was I wise not to touch it? Thanks,
Terry

Hi Terry,
We are quite confident saying this is a stinging Saturniid Caterpillar. We thought it resembled an Io Moth Caterpillar, so we researched members of the genus Automeris. We could not find a satisfactory match on Kirby Wolfe’s awesome website, until we got to Hyperchiria nausica. It looks pretty close. Leucanella hosmera looks even better, as does Leucanella saturata. We are most satisfied with Leucanella saturata or Leucanella hosmera.

Letter 29 – Stinging Nettles, not insect

Subject:  Please identify this bug
Geographic location of the bug:  London UK
Date: 11/24/2017
Time: 06:51 AM EDT
Hi there
Please could you help me identify this bug.  It bit/stung me.
How you want your letter signed:  Shivi

Dear Shivi,
Where is the bug?  All we see are leaves, and they appear to be Stinging Nettles which are pictured on The Tortoise Table.  According to the Royal Horticultural Society:  “stinging nettles (Urtica) have stinging hairs that make them quickly apparent to the gardener when weeding.”  According to The Poison Garden:  “Brushing the plant produces a stinging on the skin of varying intensity.”

Letter 30 – Stinging Rose Caterpillar

Stinging Rose Caterpillar?
Found this little guy just below an oak tree. It resembles the Stinging Rose, but the yellow color makes me believe that it can vary in color…maybe one of a few instars? Thanks,
Jose Covas

Hi There Jose,
The Stinging Rose Caterpillar can vary in color considerably, from greenish yellow to bright orange red. According to BugGuide, in addition to rose leaves, the caterpillar also feeds on the foilage of: “apple, cottonwood, dogwood, hickory, oak, redbud, sycamore.”

Letter 31 – Stinging Rose Caterpillar

Bright yellow with spines
Hi!
I was standing next to my rose bush and I thought my Blue Girl should not have yellow flowers. So when I looked a little closer I found this creature. It was attached to the rose leaf like a slug but it was colored very beautiful. Any idea what this is or what it will be? I live in Alpena, Arkansas. It is in the Northwest part of the state.
Thanks,
Angie

Hi Angie,
We were sure this was a Slug Caterpillar, but not sure of the species. That is why we wrote back for your location. Then a web search led ut to a University of Arkansas site that identified your Stinging Rose Caterpillar, Parasa indetermina. The site we mentioned has images of the adult moth as well. The caterpillar on that site has a red background color your specimen lacks. The yellow version is more common.

Letter 32 – Stinging Rose Caterpillar

Another Stinging Rose Caterpillar
This beauty was seen at Mammoth Cave National Park in KY this past weekend. My 12 year old son, a true entomologist, found it and stumped the rangers when he asked them to help identify it. We found your website when we got home and then followed the link from the other picture of the same caterpillar. Very neat little critter. We had him on the lid of a clear plastic container for a while and could watch the way his legs moved, which is unlike any other caterpillar we had ever seen! More like a slug than a caterpillar! Thank you for helping us to identify him. We have bookmarked your site for future use!
Cindy (mom) and Eddie (son)
Dry Ridge KY

Hi Cindy and Eddie,
We are thrilled you were able to identify this lovely specimen of the Stinging Rose Caterpillar, Parasa indetermina, because of our site.

Letter 33 – Stinging Rose Caterpillar

catipillar
I found this caterpillar on my redbud tree august 18, 2006 in Callaway county, Missouri while filling my hummingbird feeders. I didn’t think much about it except that I had never seen one like it before. I forgot all about it and the next day when I reached for one of my feeders the back of my hand started stinging. I looked to see what I came into contact with and there was that same caterpillar. I took some pictures of it and put it back in the tree.(Away from my feeders). From what I could find, I think it might be a Stinging Rose Caterpillar. Am I correct? All the other pictures I have seen has an orange body. By the way your website is GREAT!………
Gale Williams

Hi Gale,
You are correct. This is a Stinging Rose Caterpillar, Parasa indetermina. Bugguide lists redbud as a host plant as well as apple, cottonwood, dogwood, hickory, oak, sycamore and the namesake rose. There is some degree of color variation in the caterpillar. Some lack orange entirely, some being mostly orange, and some somewhere in-between like yours.

Letter 34 – Stinging Rose Caterpillar

Subject: strange caterpillar
Location: Rolla, MO
August 24, 2013 12:07 pm
Hi, I found this on my Japanese Maple tree this a.m. It’s beautiful but scary all at once. I live in Central Missouri.
Thanks so much!
Signature: Sarah Farmer

Dear Sarah,
Handle the Stinging Rose Caterpillar, Parasa indetermina, with caution, as it is capable of producing a painful sting.  Interestingly, BugGuide does not list maple among the food plants, which are listed as:  “Hosts of the stinging rose caterpillar include apple, cottonwood, dogwood, hickory, oak, redbud, sycamore and rose bushes.”

Letter 35 – Stinging Rose Caterpillars

unknown “slug-a-pillar” on blueberry bush
August 31, 2009
Dear bugman,
We found 4 of these critters who have stripped a small blueberry bush of its leaves. Three as you see are orange, black stripe down the middle with a little yellow stripe on the outside of the black. They have fleshy barbs that have bristles on them. No apparent feet. They move by a ripple like a slug and poop like a caterpillar. We were unaware of the underside until we put plastic wrap(with holes)on top of the container and they move across it – but leave no “trail”. The other one is yellow with a middle stripe that isn’t as dark as the orange ones – it looks more brownish red and its underside is orange. The undersides almost appear to suction as they move. We live in the Piedmont of NC, they were found Aug 30th, 2009 a young blueberry plant. What is this critter?
Help appreciated, Donna
Advance, NC

Dear Donna,
According to BugGuide, the Stinging Rose Caterpillar, Parasa indetermina, feeds on “apple, cottonwood, dogwood, hickory, oak, redbud, sycamore and rose bushes.”  Thanks to you, we can add blueberry to the list.  As the images on BugGuide show, there is considerable variability in the caterpillar coloration and markings.  Beware, as the name implies, if incorrectly handled, the Stinging Rose Caterpillar can sting.

Letter 36 – Stinging Saddleback Caterpillar

Subject: What’s that caterpillar
Location: North Carolina
August 27, 2015 7:19 am
Hi Bugman! I love your site! I used you years ago and remembered you today when my daughter found this caterpillar. I was pleasantly suprised that you are still online. Thank you! She found this in Chapel Hill, North Carolina when weeding her garden. She only noticed it because it jagged or stung her arm. Not sure what it was feeding on. Thank you for your time.
Signature: Marsha

Dear Marsha,
The stinging capabilities of the Saddleback Caterpillar, Acharia stimulea, are well documented online including on Featured Creatures where it states:  “The saddleback caterpillar is encountered most frequently as a medically significant pest, and has minor effects in landscaping and agriculture.”

Letter 37 – Stinging Silkmoth Caterpillar from Brazil

Green Stinging Catterpillar
Location: Jaraguá, São Paulo city, Brazil
March 3, 2012 1:31 pm
Hello!
This beautiful stinging caterpillar, certainly belongs to the genus Automeris, but I cannot tell the difference between the larvae of A. naranja http://www.scielo.br/pdf/rbzool/v24n3/a01v24n3.pdf and A. umbrosa http://www.silkmoths.bizland.com/kwaumbrosa.htm.
The PDF says in the 10th page that ”Comparisons of descriptions of eggs, larvae and pupae made ​​by Bourquin (1948) with the observations of this study indicate that, if that author has created A. umbrosa, immature stages of both species are very similar. Lemaire (2002) notes that there are no conspicuous differences between the last instar larvae of these species.”
Signature: Cesar Crash

Dear Cesar,
Congratulations on identifying this caterpillar as being in the genus Automeris, a group that has defensive stinging spines on the caterpillars.  We will copy Bill Oehlke on our response to see if he is able to provide a species identification. 

Letter 38 – Stinging Silkworms from Belize

Subject: mass of prickly caterpillars
Location: Toledo District, Belize
December 19, 2014 12:50 pm
Hi, Bug Folks,
I’ve seen individuals of this caterpillar in the past, but never masses like this. They are feeding on a common wild shrub called “polly redhead” in Belize. I’ve seen it in FL nurseries as “fire bush”.
So, WTB?
Thanks.
Signature: Tanya

Dear Tanya,
We believe these are stinging Silkmoth Caterpillars in the genus Leucanella, but in doing some research, the only species we can substantiate from Belize is Leucanella acutissima, but we did not locate an image of the caterpillar.  We are going to contact Bill Oehlke to see if he can substantiate the species, and since he is lacking images of the caterpillar of  Leucanella acutissima, we suspect he may request permission to post  your images to his comprehensive site.  If this is another species in the genus, he may also want to request permission to post the images as a record of a new species in Belize.  We hope you will grant him permission.

Update:  We found some images of the caterpillar of Leucanella acutissima on Bio-Nica and they look correct.

Bill Oehlke responds
Daniel,
Those seem a good match for acutissima larvae. There are a couple of other species documented from Mexico that have not been documented fromBbelize, but I would not be surprised if they are also present
In Belize.
Bill

Letter 39 – Probably Stinging Saturniidae Caterpillars from Brazil

Unknown Stinging Moth or Butterfly Stinging Caterpillar from Brazil.
Tue, Feb 17, 2009 at 9:24 AM
Mr. Bugman, (this is my second e-mail…I am trying to be fortunate enough to get a little of your precious time to help me, so I can explain it to my children.)
This was found under the dirt (which my daughter stepped on it! Very painful!). Also on the banana trees and fruit trees around the area including oranges and also some coconut trees. This was on June 26, 2008 in Juazeiro do Norte, Ceara. Brazil. Winter time in the northeast area, temperature around 30F. I have looked all over the computer archive, also books in the library and book store. Could you help me to identify it. My sincerely gratitude. I hope I am not “Bugging” you too much.
Marianne Targino-VanBeber
Northeast Brazil, City: Juazeiro do Norte

Dear Marianne,
We are sorry we did not answer your previous email, but it is impossible for us to respond, or even read, every email we receive. Since we just identified a stinging caterpillar from Mexico, your subject line caught our attention. We can tell you that these are not butterfly caterpillars, but for the moment, the best we can provide is that they are moth caterpillar , possibly related to Buck Moths or Io Moths in the family Hemileucinae. We will try to do some additional research when we have time, or perhaps one of our readers will be able to provide you with an identification.

Hi Daniel and Marianne:
Unfortunately the picture is a little fuzzy and it is difficult to make out details. Finding them “under the dirt” is a bit confusing as well. However, let’s try something and perhaps Marianne can help us out with some more information. They look like large caterpillars (?) and my first inclination is to suggest that they are Saturniid moths (family Saturniidae). They look like they could be in the genus Periphoba, possibly P. hircia which is common throughout northern South America. However, there are several Periphoba species found in that part of Brazil and they apparently are all quite similar. For comparison, I have included links to P. hicia and P. arcaei, a related species that is primarily from Central America. All caterpillars in this genus are capable of inflicting an extremely painful sting. Regards.
Karl
http://www.silkmoths.bizland.com/kwphircia.htm
http://janzen.sas.upenn.edu/Wadults/photopage.lasso?photocode%20dotj=DHJ25358.j

Dear Daniel,
Thank you very much for your reply.
I also want to thank Karl’s comments.
That day it was “rainning” green caterpillars. I wonder if one fell from the tree and was covered with dirt by accident and eventually my daughter stepped on it!
I was kind of scared to get any closer to one to take a better picture; but they were about the size of an index finger.:)
Marianne