Stinging Caterpillar: All You Need to Know for Safe Encounters

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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:

Name Appearance Stinging Mechanism
Spiny Oak Slug Green or brown with noticeable spines Poisonous bristle spines
Flannel Moth Fluffy and brown with hidden spines Venomous setae (bristles)
Buck Moth Large, black and white with spines Venomous spines
Puss Caterpillar Furry and beige Venomous setae (bristles)
Saddleback Caterpillar Green with a brown saddle pattern Irritating spines
Io Moth Green with white and red stripes Venomous fleshy protrusions

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:

Caterpillar Size Color(s) Features
Puss about 1 inch Dark brown/grayish black Fuzzy appearance
Buck moth 1-2 inches Black, red, white Spiny body, stripes
Flannel moth varies White, yellow, black Long, wispy hairs
Io moth 2.5 inches Lime-green Horn-like spines, stinging hairs
Saddleback varies Green, brown Saddle-like pattern, irritating spines
Hickory tussock 1-1.5 inches White, black Long, wispy hairs
White flannel moth varies Yellow Wispy white hairs
Spiny oak slug varies Green, yellow Rows of spines
Stinging rose < 1 inch Brightly-colored Spine-covered horns

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 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.

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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:

Caterpillar Description Adult Form
Buck Moth Dark-colored body with red spots, stinging hairs present Brown moth with white spots
Flannel Moth Furry appearance, yellow or beige color, venomous spines Yellow to orange moth
Puss Moth Hairy body, often white to gray in color, toxic spines Pale gray moth
Io Moth Green body with white and red stripes, short venomous spines Large moth with “eye spots”

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:

Species Appearance Sting Severity Host Plants
Automeris io Colorful eyespots on wings, spines on caterpillar Moderate Various plants
Megalopyge opercularis Resembles a tuft of fur, hidden spines Severe Trees and shrubs
Parasa indetermina Seven pairs of spine-covered “horns”, spiny bumps Intense Roses, trees, shrubs
Euclea delphinii Spiny oak-slug appearance with short spines Mild Oak, willow, cherry

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!


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. 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.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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34 Comments. Leave new

  • Hi, it is now 2009 and I am wondering if anyone ever ended up identifying this nasty furry caterpillar shown here. I too have just had an awful encounter with one of these, also in in the Yucatan peninsula of Mexico. It dropped out of a tree and stung me on the leg, but the systemic effects of the sting were horrible (incredible muscle spasms, abdominal pain and intense nausea) such that I also 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. Any entomologists out there looking for a challenge??? Would sure love to know what this nasty little bug was…

  • there has been a poisonous cater pillar called an assassin caterpillar that contains a hemotoxin that produces bleeding from under the nail beds nose mouth and eyes be careful

  • it looks like a hairy caterpillar but the hairs are actually barbed. they are green in color and considered extremely dangerous. with out the anti-venom you are likeley to die with in 15 hours

  • Hmm…to me this looks very similar to a recent post by Arina from Malaysia (, that I suggested was probably a Blue-striped Nettle Grub, Parasa lepida (Limacodidae). Links to photos were included in my comment to that post, but here is another one from Malaysia: In this case it is referred to as a Green Mango Caterpillar, but I am pretty sure it is the same species. Perhaps it is another common name. Caterpillars of the Blue-striped Nettle Grub are generalists and do feed on mangos and a wide variety of palms (e.g.; Chamaedorea elegans). Regards. K

  • I too happened to be stung by this nasty little fellow last week. It apparently is a flannel moth catepillar. I was on Isla Mujeres and the locals have a name for it but I cant find that anywhere. The doctor I eventually summoned says the toxin is sort of a neurotoxin. My pain was excrutiating and went from my hand up into my chest. I responded to injections of steroids and narcotics which lessened my pain to about 8 hours not counting the subsequent 10 hours of nausea and vomiting. Without treatment I guess it lasts a day or two!

    The developing new park area Garrafon on Isla Mujeres is crawling with these and there are no warning signs. Unfortunately many more tourists will likely do as I did and pick one up to look at it.

  • Due to my science (MD)background and stinging memory of the recent event, I actually dug up a bit more info on the flannel moth catepillar. The genus and species that stung me is Megalopyge lunata. Its inviting bristles are called setae and break off in the skin releasing the “toxins”. There isnt just one chemical but many have been identified such as proteolytic enzymes, plasminogen activators, histamine, serine esterase, etc. Many of these are inflammatory mediators and thus respond to steroids or even anti histamines. If traveling allergy meds such as loratidine or benedryl and/or stomach meds like ranitidine could prove helpful if a doctor is not available. While there have been life or limb threatening reports from stings, over 90% mainly have intense pain out of proportion to clinical findings.

    • My infant son just stepped on one in the yucatan this afternoon. Could you tell me where you found your info. I cannot find any info.

  • I also found this exact caterpillar today. I am located in Panama, in a neighborhood called Los Rios, just to the East of the south end of the canal. Thanks for IDing it, my 6 yr old daughter was curious.

  • I have this larva in a jar. As soon as I caught it, it started spinning. It is now encased in a cocoon on the side of the jar, which allows me to look into it. Unfortunately, I can’t get very good pictures. Of what’s going on inside, but I will take a picture of the adult as soon as it comes out.

  • Really interesting how closely this caterpillar resembles the Gulf Coast Fritillary as well–which also feeds on passionflower!

    • We thought the same thing, and as things turned out, the Tawny Coaster and the Gulf Fritillary are both in the same subfamily Heliconiinae.

  • I’ve had one of these fall out of a tree and land on my neck. It felt like someone laid a burning cigar on me as soon as it landed on me. The pain will go away in about :30 to an hour, but the burn mark will be there for about a week.
    I use Davis Kill-A-Bug IX (or XV), it kills anything that moves.

  • I’ve had one of these fall out of a tree and land on my neck. It felt like someone laid a burning cigar on me as soon as it landed on me. The pain will go away in about :30 to an hour, but the burn mark will be there for about a week.
    I use Davis Kill-A-Bug IX (or XV), it kills anything that moves.

  • i looks this caterpillar by sri lanka

  • I touched one when i was 8 years old. I was playing in the back of the house and saw it climbing a tree. I touched it and up to this day i remember my entire right side going numb like i was shocked by electricity. I was fine 2hrs later . I’m 52years old now and that is something I’ll always remember.

  • just encountered a flannel moth catepillar in my wife’s bed at 3 am. I picked it up with a kleenex, but it stung through the kleenex. Then used a paper towel and hammered it with a shoe. still did not kill or even squash it. its now in a jar and moving a little slower. We are in Lake chapala area near juadalahara Jalisco mx. got a red spot when the spines pricked me and minor discomfort but no other systems yet…..Jan 15 2016…….wife can’t get to sleep now! moved to my bed!

  • Ugh, great… I’m leaving for Isla Mujeres in six days. I’m glad to know about this in advance but also not looking forward to my trip as much. 🙁

  • Nigel.S.Paltoo
    May 16, 2016 9:11 am

    Got bitten yesterday …tried every household chemical and medicine to ease pain…mosquito repellant mixed with colgate mint winter green toothpaste and loads of ice works wonders and four benadryl capsules take two first and two after two hours

  • I saw that cattlerpillar on a TV show called “Natures deadliest” episode “Brazil”. They called it an assassin bug and said it kills you in 15 hours if you don’t make it to the hospital. It makes you bleed from every orifice in your body to death. Bleed out the eyes, ears, butt, etc….

  • Anyone has a n original pic of this bug. Its a life and death situation.

  • Krista Orangutan
    January 18, 2018 2:28 pm

    I am not sure about the “perfectly harmless” description. All of the local people say be careful and do not want to touch it.

  • I can agree with what the locals say Krista after inadvertantly touching it. Quite a sting but not as bad as I would have expected. More like a wasp sting which didn’t last for too long fortunately.

    And WTB, great work and thanks for the info

  • I can agree with what the locals say Krista after inadvertantly touching it. Quite a sting but not as bad as I would have expected. More like a wasp sting which didn’t last for too long fortunately.

    And WTB, great work and thanks for the info

  • We have 4 of these
    Stinging Rose Catepillars on our Japanese Maple. We live near Chouteau, Ok.

  • Good morning, I have the same caterpillar in my garden, I live in Costa Rica, in Guanacaste, in the mountain (700m) close to Tilaran. The color is correct on the picture mine is also bubble gum pink with spines. I have a picture if you need it.

  • Panama or Trinidad and Tobago. My little daughter got stung yesterday ( 07 July 2022) by that exact creature and we live on the North Coast of Trinidad and Tobago. I found this convo because we had to do an emergency google search of the caterpillar to know what to do because she was screaming her head off.

  • I got stung by this said shinny today 30th August 2022 in Trinidad in the St.James area and it hurt like hell then a numbness in my arm a few hours well.

  • I got stung yesterday morning in my 30 October 2022 home got hospitalized

  • Emiliana Duarte
    July 3, 2023 9:31 am

    Hello! I live in Caracas Venezuela and just saw the exact same pink caterpillar a few minutes ago! Can I send you a video?


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