Puss Caterpillar or Asp — General Information 111

— This article by Jerry Cates, first published on 7 March 2010, was last revised on 22 January 2014. © Bugsinthenews Vol. 11:03(09).


Blonde Puss Caterpillar in Pine Bark

Blonde Puss Caterpillar in Pine Bark

The puss caterpillar is the larva of an insect in the order Lepidoptera.

More specifically, it is a flannel moth (so-called because the adult moth is clothed in short fine hairs that resemble flannel in texture) in the family Megalopygidae: from the Greek root μεγας (MEG-as) = great, vast, large + the Greek root πυγη (PIDGE-ee) = rump, tail + the Greek patronymic suffix –ιδες (eye-DEES) commonly used in zoological taxonomy to indicate a family name, in reference to a family of moths typically having an exaggerated tail, honoring the fact that these caterpillars often–but not always–trail a conspicuous tail of hairs; this family is presently represented by 23 recognized genera that are found in North America and in the New World Tropics; in North America as many as 44 species — generally described as that group of organisms capable of interbreeding and producing fertile offspring — have been described, some of which may be synonyms, but all of which are known, while in the larval (caterpillar) stage, to produce extremely painful stings in humans who come into contact with them.

The species cited most often is Megalopyge opercularis, but a number of other species present a similar outer guise, are equipped with near-identical envenomating structures, and produce a similar sting on contact with human skin.

Most are now considered to be members of the genus Megalopyge , but the crinkled flannel moth–also known as the black-waved flannel moth–is classified by some authorities as a member of the genus Lagoa (Lagoa crispata), and by others as Megalopyge crispata.

In the material that follows, because the gross features of most, if not all of these moths are essentially identical, no attempt will be made to distinguish between them.

Puss Caterpillar on Twig

Puss Caterpillar on Twig

Puss Caterpillar on Yaupon Leaf

Puss Caterpillar on Yaupon Leaf

The larval stage of this insect is a small (2 cm. long, 1 cm. wide), woolly, pussycat-appearing caterpillar.

Its innocent, cuddly-looking appearance belies the numerous sharp, venom-laden spines, hidden beneath its luxuriant coat of soft hairs.

Because these caterpillars appear as innocuous pieces of fluff, children and adults are tempted to pick them up.

Even those who know their nasty reputations find it difficult to believe that these beautifully adorned animals — that have all the earmarks of a benign, friendly, comforting creature —have the power to move powerful, grown men to tears of pain and agony.

One touch, however, quells all doubts in a blinding instant of truth. Talk about pain… Wow! The puss caterpillar knows how to dish it out most of the time (some, thankfully, don’t sting, probably because a chance genetic mutation prevents their bodies from manufacturing the venom that otherwise fills their spines).

Puss Caterpillar Sting on Right Bicep

Puss Caterpillar Sting on Right Bicep

Puss Caterpillar Sting Under Arm

Puss Caterpillar Sting Under Arm

The spines that stick out from each verruca (a Latin word meaning “wart”; in this case a glandular excrescence on the skin of the caterpillar that houses venom glands and is adorned dorsally with sharp, hollow, venomous spines) on the body of the caterpillar usually , but not always, induce an immediate onset of excruciating, unrelenting pain.

The pain usually radiates rapidly to the lymph nodes in the armpit or groin, and then to the chest.

Though only rarely representing a true medical emergency, these symptoms have the feel of a genuine, serious, life-threatening event.

As a result, it is common for victims of puss caterpillar stings to seek medical assistance at hospital emergency rooms, where they hope that the E.R. staff will be able to apply appropriate medical interventions.

Sometimes Emergency Room physicians, nurses, and EMTs recognize the puss caterpillar’s distinctive sting wound immediately, but — surprisingly often — these personnel have no knowledge of the puss caterpillar or its sting, much less of the most effective medical interventions the sting calls for.

Individuals who go to emergency rooms for treatment of puss caterpillar stings may be misdiagnosed by inexperienced medical personnel as suffering from a wide range of acute and generally serious medical conditions.

Healthy Puss Caterpillar Ventral Surface

Healthy Puss Caterpillar Ventral Surface

Within minutes or hours of the sting event, a halo of reddened skin, caused by capillary congestion, forms. The reddened tissue is locally sensitive, painful, and warm or hot to the touch.

The skin remains reddened but otherwise unmarked for minutes or hours. As the local redness subsides, a pattern of darker, raised, nodular lesions forms, usually within 24 hours after the sting. These darker lesions are arranged in a characteristic pattern.

The sting pattern varies based on which portion of the caterpillar touches the body.

The puss caterpillar’s underside is shown in the photo at right. This portion of the caterpillar contacts the surface of the caterpillar’s track as the caterpillar crawls along. Note the way the hairs along the edges of the body emerge from swollen “warts” or verrucae (raised tubercular ridges, arranged along the median of each body segment).

Though the soft hairs themselves are harmless, these same swellings also sport a multitude of sharp, venomous spines capable of injecting the caterpillar’s venom into the skin of a sting victim.  If the underside is pressed against the body, the visible sting pattern (that shows up later) will follow this shape; if one side of the caterpillar is involved, the sting pattern is usually that of a crosshatched triangle, with each of the verrucae involved in the sting showing in the pattern. If the upper surface is pressed against the skin, the sting pattern is that of a crosshatched oval.

The sting pattern usually begins to show within 24 hours, but the full pattern may not be expressed for hours or days after the sting occurs.

The photos below show puss caterpillar stings on a right foot foot (L) and forearm (R). The lateral (side) surface of a caterpillar had been crushed against the foot, while the stings on the forearm were caused when the upper bodies of two caterpillars were crushed by pressing the arm against a railing where the caterpillars were crawling. Note the regular pattern of dark red spots in the photos; these spots correspond to the verrucae in the body of the caterpillar, showing where the concentrations of fragile, venomous spines penetrated the sting victim’s skin. In the majority of cases, these spines break off during penetration and slowly release their store of venom as long as they remain embedded. Each spine, as described by Nathan C. Foot in his 1921 paper on the subject, is one-third to one milimeter long, and 15-45 microns in diameter. Such microscopic structures cannot be seen with the naked eye. However, because human flesh tends to push embedded foreign objects outward, even spines that have penetrated deeply will move toward the surface of the skin–where they may be extracted manually–within a relatively short time. This fact figures prominently in the treatment options that should be considered when dealing with a puss caterpillar sting.

Puss Caterpillar Sting on Side of Foot

Puss Caterpillar Sting on Side of Foot

Puss Caterpillar Sting Under forearm

Puss Caterpillar Sting Under forearm

These photos were taken several hours after the sting event.


Links:   (1) Puss Caterpillar General Information.    (2) The Puss Caterpillar’s Stinging Apparatus. (3) Puss Caterpillar Extermination. (4) The Puss Caterpillar’s Natural Predators. (5). Puss Caterpillar Stings–Medical Interventions. (6) Puss Caterpillar Stings–Home Remedy First Aid Measures.



  • Kingdom Animalia (ahn-uh-MAYHL-yuh)  — first described in 1758 by the Swedish taxonomist Carolus Linnaeus (1707 – 1778), using the Latin word animal = “a living being,” from the Latin word anima = “vital breath”, to refer to multicellular, eukaryotic organisms whose body plans become fixed during development, some of which undergo additional processes of metamorphosis later in their lives; most of which are motile, and thus exhibit spontaneous and independent movements; and all of whom are heterotrophs that feed by ingesting other organisms or their products;
  • Phylum Arthropoda (ahr-THROPP-uh-duh) first described in 1829 by the French zoologist Pierre André Latreille [November 20, 1762 – February 6, 1833], using the two Greek roots αρθρον (AR-thrawn) = jointed + ποδ (pawd) = foot, in an obvious reference to animals with jointed feet, but in the more narrow context of the invertebrates, which have segmented bodies as well as jointed appendages;
  • Class Insecta (ehn-SEK-tuh) — first described in 1758 by the Swedish taxonomist Carolus Linnaeus (1707 – 1778), using the Latin word insectum, a calque of the Greek word ἔντομον ( EN-toh-mawn) = “(that which is) cut into sections”; comprised of arthropods with chitinous external (exo-) skeletons, a three part body composed of a distinct head, thorax, and abdomen, the midmost part having three pairs of jointed legs, and the foremost part having a pair of compound eyes and antennae;
  • Subclass Pterygota (tare-ee-GOH-tah) — first described in 1888 by Lang, using the Greek roots πτερυξ (TARE-oos) = wing, to refer to insects with wings, or that had wings but in the process of evolution have since lost them;
  • Infraclass Neoptera (nee-OPP-tur-uh) — first described in 1890 by the Dutch entomologist Frederick Maurits van der Wulp (1818-1899) using the Greek roots νεος (NEE-ose) = youthful, new + πτερυ (TARE-ohn) = wing, to refer to winged insects that are capable of folding their wings over their abdomens, in contrast to more primitive winged insects that are unable to flex their wings in this manner (e.g., the dragonflies, in the infraclass Paleoptera);
  • Superorder Endopterygota (ehn-doh-tare-ee-GOH-tah) — first described by the English physician and entomologist David Sharp (1840-1922) using the Greek root ενδον (ENN-dohn) = within + the established expression pterygota (see above) to refer to insects within the latter subclass that undergo complete metamorphosis, i.e., larval, pupal, and adult stages;
  • Order Lepidoptera (lep-uh-DOPP-tur-uh) — first formally described in 1758 (though he coined the expression in 1735, informally) by the Swedish taxonomist Carolus Linnaeus (1707 – 1778), using the Greek roots λεπιδωτος (lepp-eh-DOH-tose) = scaly + πτερυ (TARE-ohn) = wing, to refer to insects with scales covering their wings, i.e., the moths and butterflies;
  • Family Megalopygidae (megg-uh-low-PIDGE-uh-dee) —  from the Greek root μεγας (MEG-as) = great, vast, large + the Greek root πυγη (PIDGE-ee) = rump, tail + the Greek patronymic suffix -ιδες (eye-DEES) commonly used in zoological taxonomy to indicate a family name, in reference to a family of moths typically having an exaggerated tail, honoring the fact that these caterpillars often–but not always–trail a conspicuous tail of hairs; this family is presently represented by 23 recognized genera that are found in North America and in the New World Tropics; in North America as many as 44 species have been described, some of which may be synonyms, but all of which are known, while in the larval (caterpillar) stage, to produce extremely painful stings in humans who come into contact with them;



Questions? Corrections? Comments? BUG ME RIGHT NOW! Feel free to e-mail jerry.cates@bugsinthenews.info. You may also leave a detailed comment in the space provided below.

111 thoughts on “Puss Caterpillar or Asp — General Information

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  1. Alison Price Mar 16,2010 12:13 pm

    Tue, March 16, 2010 10:13 am: I think this (i.e., a puss caterpillar ) is what fell into my eyeball from a tree and stung me 5 and 1/2 days ago and the eyeball is STILL sore.

    I only flushed it with water and saline.

    Wondering what else I can do??


    Jerry–Wed, 17 Mar 2010 10:54:39 -0700: How sore is it? I presume the pain is bearable, or you’d have gone to see your physician by now. Something very similar happened to me several years ago, when I rubbed my eye while–unbeknownst to me–several puss caterpillar spines were on one of my fingers. The spines immediately caused excruciating pain, alerting me to what I’d done. Like you, I flushed my eye with water for several minutes; the pain did not go away immediately, but was gone within a few hours. Unfortunately, outside of a medical setting, there isn’t much that an individual can do beyond flushing with water and/or saline. It may be time for you to see the doctor…

    Alison–Wed, Mar 17, 2010 11:18 am: Each day it’s better, but it’s still not all the way back and tonight will be a week since it happened.

    My medical clinic takes all day to get in as a walk-in and that’s the only reason I haven’t gone.

    I just hope no permanent damage was incurred.

    Scared me that the muscles behind the eye got involved and generally the whole area around the eye socket..even up in my sinus area by eyebrow.

    I’m in Florida.

    Thanks for responding to me!

    Jerry–Wed, 17 Mar 2010 12:02:51: That sounds par for the course, Alison. It isn’t too surprising that the musculature surrounding the eyeball became involved, as puss caterpillar venom seems to migrate from the sting site to other areas rather easily. Has the sting affected your vision? And has the area around the eye swollen or reddened? In my case there were no obviouos signs beyond the pain.

    Alison–Wed, March 17, 2010 12:08 pm: The white of the right eyeball was reddened in the area above the iris, but no swelling or blurry vision, thank God!

    For the first 4 days, it hurt to move the eyball at all (using the muscles which control it).

    So odd..a one in a million situation that, when I set out to take a nightly walk in the dark (for the first time in months of all things!), I set out 3-5 steps looking straight ahead and this thing fell from the tall trees above me right into my eyeball!

    I ‘ve never been SURE it was that… I didn’t keep it or look at it… very dark there… my eye stung so badly I was screaming with pain as if acid had been thrown into it and ran back to the house to flush it.

    But it FELT like a caterpillar when I plucked it off ( felt soft and rounded)..and made sense that it could have been since it probably fell on my eyelid and then the feet curled downward into the eyeball itself.

    I have such luck!

    Jerry–Wed, 17 Mar 2010 12:35:49: Please keep me posted on your progress. I’m going to post all your comments and my replies, if you don’t mind, as others will be interested in your experience, and especially in how long it takes you to fully recover.

    Alison–Wed, Mar 17, 2010 12:45: That’s fine, Jerry.

  2. astriddestler Apr 20,2010 1:45 pm

    Actually, I found one of these caterpillars once and captured it very easily. It was very soft to the touch, and I just sat and stroked it for hours. I thought the little guy was so cute and fluffy, I even rubbed the soft fur on my cheek. And I never got even a slightly red rash from him. Maybe they can retract their stingers into their bodies and when frightened, just stick them out. Because I don’t think he felt threatened or anything. So I was fine.

    But I would like to know what damage could this insect can do in adult form?


    Hi. Thanks for your comment.

    These caterpillars are the larval forms of the flannel moth. The caterpillars spin a cocoon around themselves, and metamorphose into the flannel moth inside the cocoon over a period of weeks or months before emerging to mate and, in the case of the female, lay eggs that hatch into a new batch of caterpillars. The moths, themselves, are harmless.

    Every year a number of reports come in, like yours, describing harmless caterpillars that were stroked and handled without causing any stings. Apparently some of the caterpillars are either without stinging spines, or the spines have no venom in them. I write about this on a separate page. A link is provided below.

    Unfortunately, I’ve not yet had the opportunity to examine a non-stinging puss caterpillar under the microscope in order to determine if the cause is a lack of stingers or a lack of venom.



  3. Laura Apr 27,2010 11:20 pm

    Last March my daughter had a run in with one of these fellows and her symptoms were much more severe. She was on her way home from the movies (driving) when she got stung. She said it was excruciating pain. About fifteen minutes later her friends said she thought she was driving fine but was actually slumped over the wheel, coasting down the highway. By the time she got home she had no use of her arm. She was stung between her shoulder and chest then on her middle finger when she was trying to remove it. Anyways, she was hospitalized for a week. The paralysis wore off in a few days, but her arm remained weak for a number of weeks beyond that. She was medicated with benadryl, epi, and heavy doses of steroids. She now suffers from neuropathy that the doctors say could go away in a few years.
    This spring my porch has been covered with these caterpillars. I was wondering if there is a specific type of tree, bush, or flower that they are attracted or if there is a repellent I could use to reduce my daughter’s risk.

  4. Sharon May 10,2010 8:17 am

    I found one wall and window of my house covered with blood spatters and streaks. It would only clean off with clorox. The next day I found 1/2 as much blood again and saw a couple of caterpillars on the wall. They are brown in color and close to an inch long. I would like to know what they are, how to get rid of them and where they might be coming from and also how long their season is?

    Thank you. I am in Daytona, Florida



    The blood splatters are a mystery. Can you photograph them next time? And also get photos of the caterpillars. Send those in and I’ll have a go at it.



    12 May 2010: Sharon wrote back:

    They were here for only about 10 days and are now gone – I don’t know where or into what – so i can’t take a picture of them. If they come back, I will send you a pic.

    My reply: That’s about par for the course, Sharon, as long as they are not sprayed with pesticides that kill their natural predators their infestations are self-limiting and rarely recur in the same area anytime soon. Please keep me posted on things–Jerry

  5. Barb May 19,2010 1:21 pm

    I think my grandmother called these Asps? Is that the same thing?


    Yes, Asp is another name for these caterpillars.


  6. Henrietta Fern Jun 19,2010 8:34 pm

    Today i was cutting my yard and trimming some trees, i was not aware that the caterpiller was there when i picked up the branches i crushed one, In second i felt servere pain running from my fingers to my arm and chest, I couldn’t take it anymore, I went to the day and night clinic and they gave me two shot and medication, they also mentioned it would take several days for the pain and the numbness to go away. I’m home now (6-19-2010) but not feeling good at all. pleaase keep away from this, the pain is to much!


    Editor’s Note: Read through the material on first aid measures, posted at https://bugsinthenews.info/?p=555 and in particular make sure to use tape to remove the spines. That is perhaps the most important step one can take to limit the pain that comes with a puss caterpillar sting.


  7. Ryan Jun 24,2010 4:35 pm

    I have yet to see one of these creatures, but reading these stories terrifies me. I was wondering if you could let me know where they are found, so I can know if I should look out for them or not.

  8. Sandi Jun 30,2010 2:20 pm

    Is there a natural way to get rid of these besides stepping on them? I hate to use Sevin or anything like that? Thanks.


    Editor’s Note: Suggested approaches to naturally exterminate these caterpillars are discussed on the following web page:

    Exterminating Puss Caterpillars

    Read this over and consider following the suggestions provided.


  9. Lisa Jun 30,2010 11:30 pm

    My husband was stung by one on the top of his hand this evening. Immediate pain and redness, followed by swelling and pain. He has felt tingling down into his fingers and up to his elbow area as well. We have applied cortisone and taken antihistamine orally. What are the signs to watch for so that we would know if medical help is neccessary? You have a great site…wish we would have looked a few hours earlier.
    Thank You,


    Editor’s Note:


    All the symptoms your husband experienced are typical for a puss caterpillar sting. You don’t mention using tape to remove the spines; if you have not done this yet,please do so right away as the tape helps considerably even hours or days afterward.

    Read the material on First Aid for Puss Caterpillar Stings.

    It is rare for these stings to progress beyond the symptoms you described. Anaphylaxis, or allergic reaction to the venom, is unusual. The most serious signs are difficulty breathing due to constriction of the airway. I am not aware of any such reactions resulting from puss caterpillar stings, however.

    The most important thing is to relieve the pain, and one of the most important ways to achieve that is to use tape to remove the microscopic spines from the sting site and, for some, to apply poultices as described in the material posted at the above link.


  10. Robert Jul 2,2010 10:52 am

    I got stung twice here in Marrero La. about a week ago. The pain was excruciating, burning, itching, swelling, Red and Flat at first, then Red and Raised, and spreading first on my left arm near wrist and elbow,hands inside and outer, then climbed up to my under arm them stomach, Buttocks,legs, under my knees, calves, ankles, feet top and bottom, and toes, it was very pronounced at all of my Lympnodes, the itching and burning is unbearable, I used Tape, Benadryl, Hydrocortizone cream, antibiotic, Cortizone injection, and nothing worked, Finally went to Hospital yesterday 07-01-2010 and was administered by IV 20 MG of Prednisone, Liquid Benadryl-Dexamethazone Sodium Phosphate and Liquid Zantac all by IV which took about 45 minutes, felt immediate Relief within 30 minutes,was given these three medicines by pharmacy to be taken Orally 4 to 6 times a day, then only as needed, will be followed up by Dermatology in a 7-10 Days– Thank you for you advice and information, it was extremely Helpful, I have pictures-although ugly- if you would like me to send, Thanks again-Robert—CDC AND ALL NEWS NETEWORKS NEED TO ISSUE A WARNING ABOUT THESE PUSS CATERPILLARS–THIS IS LIFE THREATENING TO ALL PEOPLE-AND EVEN DOCTORS/NURSES HAVE NEVER SEEN OR HEARD OF THESE CATERPILLARS, AND UNFAMILIAR WITH THEIR EXTREME VENOMOUS EFFECTS, PLEASE LETS WARN THE PUBLIC ABOUT THIS ASAP-Thanks Again, Robert


    Editor’s Note: Yes, Robert, please do send the photos. Glad you are doing better.


  11. sarah Jul 3,2010 12:53 pm

    My one year old came in contact with one of these this morning. We are in New Orleans, like Robert, above. The sting happened 3 hours ago and she is still crying.. lethargic. Very much in pain still. What should I do? She is 13 months old.


    Editor’s Note: Have you tried the tape to remove the stinging spines? That seems the best remedy, but it needs to be done meticulously, up to 10-15 times, to get all the spines out.



  12. Rosana Jul 11,2010 7:22 am

    This is exactly what stung me on my forearm on 7/9/10. I leaned on the caterpillar. The schools should educate children to stay away from this little creature. They cause severe pain. I felt like my arm was on FIRE. Excruciating pain. The pain radiated to my hand, fingers and lymph nodes in my armpit. The severe pain lasted for over 4 hours. These pics and the description explains exacly what to expect when you are stung by one of these. I can’t imagine a young child bearing this pain. Thank you for the information.

  13. Florida Pain Management Jul 13,2010 9:31 am

    Exposure to the caterpillar’s fur-like spines will lead to an immediate skin irritation. The caterpillar is regarded as a dangerous insect because of its venomous spines. Medical advice may be sought in case of contact with one. It is best if the venom from the spines are treated within hours of first contact. For first aid, it is recommended that you remove the spines using cellophane tape.

  14. Gail Sep 30,2010 10:34 am

    I was stung about 3 weeks ago while Dead-Heading my Knock Out Roses. I thought it was a wasp sting, but wow! I have a butterfly garden so I cut about 12 and put them in a jar thinking we had a new butterfly in the area. When I was researching the caterpillars, I realized that the pain was from the Puss Caterpillar.

    And what pain! I was stung on the bottom of two fingers, and on another finger on my other hand. Was in great pain, used ice, and took a pain pill. Did not help ease pain. Got sick to my stomach and was pretty dizzy–was hard to talk. The severe pain lasted 12-15 hours. It took me 3 days to feel well again. My hand is still sore.

    I read on another site to pull the stingers out with tape, but not realizing they were invisible, I failed to use tape. I still have markings on my fingers, so used the tape just now.

    Unfortunately, we did use a pesticide. We had noticed the flys which was unusual for our patio.

    We live in central (Prattville) Alabama, and had never heard of the Puss Caterpillar, nor has anyone in my garden club, church, etc.

    Your site is by far the most comprehensive of all those I found. Just wish there were more “warnings” out there!

    Thank you!

    Editor’s Comments:

    Gail– Some readers may not know what you mean by dead-heading your knock out roses:

    Rose and flower gardeners routinely deadhead their plants when blooms are spent. The process involves cutting the flower from the stem after it has faded and died. Most plants benefit immensely from the procedure, as it prevents seed production and conserves energy for new blooms. However, if you know anything about knockout roses, you know they don’t produce seeds, so they’ll continue blooming even if dead-heading is not done. Regardless, the presence of petal-less dead roses tends to bother most rose cultivators, who deadhead their knockouts to improve their appearance.

    I’m glad you finally did use the tape. It helps, even weeks after the sting. Keep us posted on your progress.


  15. KieraAnne Oct 21,2010 2:45 pm

    I found one of these attached to my pant leg the other day while playing in our yard with my two young sons. I had never seen one before and thought it looked like some sort of “furry slug”. I pet it and even had my two year old come over and stroke it’s “fur” to see how soft it was. Neither my son nor myself experienced any pain or discomfort. I then pried it off my pants and it sat on my finger for a moment. At that point I thought it felt like it might be very lightly stinging me somehow so I gently pushed it off my finger and into some vegetation. I didn’t have any further pain or discomfort and my finger is fine. We even came back and looked at it once more and “pet” it before going inside. It wasn’t until today that I decided to look up what kind of bug it was. I guess we were very lucky not to have to go to the hospital or anything. I’ll remember that in the future should we ever see another.


    Editor’s Note: From time to time, specimens of these caterpillars are found without the ability to sting. Why those specimens lack that capacity is not known. However, the next one you touch may send you into paroxysms of pain and agony. Be very careful.

  16. KieraAnne Oct 21,2010 2:46 pm

    Oh we’re in Texas, about an hour north of Dallas.

  17. Monica P., Miami, Florida Nov 2,2010 2:19 pm

    Dear Jerry:

    We live in Miami Florida and my son was out back playing when he yelled with absolute pain. He pointed at the ground to a fuzzy thing. I had never seen anything like that creature before. Thanks to your site, we were able to take care of my son quickly with the scotch tape. He brushed his calf against it as he left the pool enclosure to play on the swing. He felt burning pain on the calf and pinching sensation. He did get a shooting pain up to his groin area too. He cried on and off for 5 min saying it was the worst pain he has ever felt.

    Once again, thank you for providing great information and advice.

    Monica P.
    Sent from my iPad

    Editor’s Note: Monica sent this as an e-mail, rather than as a comment on the posting. She did the right thing, immediately using scotch tape to remove the spines, and the pain from the sting subsided quickly. I cannot help but believe that, if tape is used quickly after being stung by a puss caterpillar, most would report similar results.


  18. J.F., Wendell, North Carolina Dec 17,2010 4:14 am

    Dear Jerry,

    I just found your site today on the puss caterpillar. 12-17-2010.

    My daughter was curious about it since I told her my awful encounter when I was in 8th grade. I’m 35 now and remeber the pain like it was yesterday and how creepy this odd creature appeared to me. I remember it being shaped like a brazil nut with spines like a porcupine and dark in color like one too.

    I had my book bag resting beside a tree at recess and when it was time to go inside I picked up my bag and followed the class in. I went to the restroom and reached back to get a brush out of my bag and thought I had just gotten burned on the back of my arm. Turned out my arm bumped this thing that was stuck to my bag.

    I was all shaken up. I went to the office. They put it in a baggy and told me to go on to class and they would keep it in case anything happened. I went to class then almost immediately I began shaking, sweating and my arm started throbbing worse and worse. I was sent back to the office where they called my mother to come. Mother took me to doctor, they were baffled. They had to send it to Duke University to find out what it was.

    Duke finally figured it was a caterpillar puss moth. The doc gave me a shot and sent me home. The pain continued through my whole arm the rest of the day so bad I wanted to die. Then it eased up finally but I had the shape of the creature on the back of my arm for some time. I didn’t really know much about it til today. I appreciate you taking time to research this and make others aware.

    The exact location of this particular incident was at East Wake High school in Wendell, N.C.


  19. Virginia S. May 17,2011 9:21 am

    Mr. Cates,
    Last evening (5/16/2011) as I sat at the dining table using my computer, I felt a stinging sensation on my forearm near my elbow. I looked and it appeared to be a piece of oatmeal about 1/4 inch long. I knocked it off on the table and it began to move. It had a furry appearance. I got it on a piece of paper and took it outside to the bannister and put it there and then turned it over, using a magnifying glass I could see a small body and realized that it probably was an “asp” puss caterpiller. I let it go — which was probably a mistake.
    Just wanted to report that they are still alive and well in Livingston TX. Last time I saw one was 1958 in Dallas TX.
    Virginia S.


    Thank you, Virginia

    Let me know if you see any more. You may want to look around the yard to see where this one came from. Usually, where you see one, you will usually find others, often clustered on a particular shrub or tree. If you have oak trees in the yard, and cannot find any of these caterpillars in your shrubs, they may be aloft, in one or more of the oaks.


  20. Wendy M., Okeechobee, Florida 12 August 2011 Aug 12,2011 1:35 pm

    Hi Jerry,

    I am a 36 year old woman living in Okeechobee, FL. I was looking on the internet for information regarding these caterpillars as I got stung in four places (wrist, elbow, upper thigh and top of thumb) by them yesterday.

    I also had a sting several years ago prior to the 2004 Hurricane Charley here in Florida when I was cleaning up the yard in preparation for the storm; that sting ended up with an admission into the ER with respiratory distress and chest pains, along with the intense pain.

    For the first sting yesterday (all happened within 20 minutes of one another), I immediately hosed it with a high-pressure cold water hose for 5 minutes and then vigorously rubbed the sting mark on a rough (clean) rag, and that one ended up being the least severe of all. I think the high pressure water and the rubbing helped immensely.

    The other three stings I was in too much of a hurry to do the hosing/rubbing with, as I was starting to panic remembering my last sting experience in 2004, and still to hurry finish feeding my three horses before I could run back to the house.

    When I got back in the house, I immediately took 2 Bronkaid (bronchodilator containing ephedrine sulfate), 2 Benadryl, 2 Ibuprofen and 1 high-potency 7.5 mg Lortab. I was prepared to take 2 of those if need be! I did experience the severe pain and the rapid breathing that comes with the pain for about 20 minutes, but never felt the difficulity breathing or chest pains that I did in 2004.

    I took those meds at 8 a.m. and by 9 a.m. the pain was still present, an ache/burning, but it was bearable at about a 4/10. At noon, the pain was returning so I took another Lortab. I have not needed to take another since and the pain is entirely gone now although the marks remain. The mark on my thigh looks like I was burned by something.

    I have a couple questions for you, if you would be interested in answering them. The first is, does the size of the vitcim matter in terms of poison intensity? I am 120 lbs and my husband is 280 lbs. He was stung a couple of weeks ago and it did not affect him even nearly as much as it affects me. I ask this because my daughter is 60 lbs and I am absolutely terrified of her getting stung.

    My second question for you is, do you know what would happen if a horse ingested one of these caterpillars? I am extremely worried about this because all four stings yesterday came from the caterpillars hiding in horses’ hay, which would lead me to believe the horses have eaten them on occasion, or will in the future.

    My friend’s father was stung by one of these caterpillars on his neck and suffered a permanent loss of smell, due to the neurotoxins. I worry that the horses may die from an airway constriction if they ingest one of these little demons.

    Thanks for your help!

    Wendy M.



    Thanks for the excellent report. Did you use tape to remove the spines from any of the sting wounds? If not, perhaps you will do so soon, as even days after the sting using tape to pull out the remaining spines tends to aid in recovery.

    Several reports have come in over the past ten years concerning pets, such as dogs and cats, that have eaten or mouthed puss caterpillars. In a couple of cases, the animal spat the caterpillar out, probably because the spines stung the tongue and other tissues in the oral cavity, but in other cases the caterpillar was ingested without incident. In none of these cases did the animal appear to have been harmed by the experience. Horses are more vulnerable to certain toxins than other animals, but I have not received any reports about horses ingesting puss caterpillars and being harmed in the process. Given the relative abundance of these caterpillars, it seems unlikely that serious injuries would have occurred without some record of it. That suggests that horses are probably not in much danger from the puss caterpillar sting, either internally or externally.

    Of course, reports of serious injuries by these caterpillars could come in tomorrow. It would be good if you could keep watch at your stables to see if there is any evidence that your horses are experiencing any health issues from the caterpillar infestation.

    Your visit to the ER in 2004: do you still have a record of the costs incurred by that experience? If so, could you share that with me? We are compiling a study of the medical expenses incurred by those who visit their medical providers for assistance with the sting wounds, and your inputs will be of help.



    Hi Jerry, thanks for such a fast reply!

    Re the 2004 ER visit, it was covered by my insurance completely, so I paid little mind to it, however, I do have a recollection of it being around $6,000, which is probably about right as they had me hooked up to an EKG, oxygen mask and IV Dilaudid. I was there for around three hours.

    And yes, I did use tape to remove any spines, thanks to your website! I have absolutely no lingering effects today, thank God. Its amazing how much agony those little fellas are capable of.

    Regarding the horses and caterpillars, one of my horses did have some sort of bad reaction to something one time, her entire face swelled and her neck as well. It was so bad it split the skin. The vet thought he was going to have to do an emergency trach on her. His best guess was that it was a pygmy rattler bite but it leaves me wondering. Another time, she also had some kind of intense mouth irritation that I had to give her Banamine (strong pain medicine for horses) for. She’s very mouthy and always eating odd things, probably why none of the other horses every have the same troubles.

    If anything more of interest happens, I will definitely let you know about it.


  21. evilgn Sep 13,2011 9:33 pm

    Got stung by one of these today on the West Bank of New Orleans, Algiers area, I sat on it on a folding chair. I felt the sting and immediately stood up because I thought something was inside my shorts on the backside of my lower hamstring. I grabbe at my shorts to try to remove the sting from my skin, little did I know it was on the outside of my shorts getting me thru the shorts and underwear. So when i went to grab at my shorts, it managed to get the top of my index and middle finger, first knuckle. Within 10 minutes I began to experience pain in my groin and that is when I got on the internet. A few minutes of going through several websites was all it took before I realized I needed to get care ASAP, I was trying to read out loud to my wife and realized I could not get my words out, so we left and was treated with a shot, and prescription for prednizone steroid (sp) and benedryl. Its been 8 hours and my leg and finger still burn, groin pain went away within the hour, and the general dizzyness/being out of it, wore off in a bout 2 hours. I did not do the tape thing until just now, so not sure if its been too long. Oh and the originally swelling on the leg was 3 inches wide, it is now down to quarter size with lines actually, not dots…can send a pic of the current wound.

  22. Mary Wood Sep 30,2011 1:53 pm

    First – great website. I never even knew until I got stung yesterday that there *was* such a thing as stinging caterpillars! A friend found your site and got me some very helpful first aid info.

    Now, the report to add to your collection:

    I’m in Central Arizona’s Verde Valley. Suspect the asp fell out of a tree onto my work glove? Not entirely sure how it got to my chin but that’s where I was stung. And let me say that being stung *in the face* by one of these little suckers is not as pleasant as it sounds.

    Only other allergy I have that I’m aware of so far, plant or animal, is to wasps.

    The overall reaction was extremely similar to my reaction to wasp stings, except with wasps it all happens in a matter of minutes then the worst is over. This took hours. Even told my friend at first, “Heh, at least I’m not having any other reaction!” Famous last words.

    Immediate and intense pain at the sting site that got progressively worse over the next 3 hours. Somewhere between a blunt ache and stinging pain, like someone was driving a chisel into my chin.

    About 20-30 minutes later the rest of the symptoms started and they peaked and hung around over the course of several hours:

    – Very woozy/weak, like I had OD’d on muscle relaxants.

    – Stiff/sore neck and upper back. Could this be because I was stung in the upper body/head?

    – Short of breath.

    – Slight fever.

    – Nausea.

    – Headache.

    – Throat closed up a bit; hard to swallow.

    What I did for it:

    – 5 minutes after being stung I took 2 benedryl. Note all the above symptoms, so it’s hard to say how much good it did, but I suppose it could have kept the reaction from being worse?

    – 30-45 minutes after, my friend had found the info on your site and I started applying and peeling off strips of duct tape to remove the stingers. It seemed like it helped; pain went from excruciating to merely horrible. Also laid down for a bit as the dizziness was making it hard to stand/move about. Perhaps 20 strips of duct tape in all.

    – Called poison control: They didn’t have much else to add other than to wash the area well.

    – 2-3 hours post-sting I took 2 more benedryl which seemed to have a very small but noticeable and immediate positive overall effect.

    – At that time, took a hot bath which felt WONDERFUL! As often as I could, I put the affected area under the water and having it underwater like that almost totally took the pain away. I’d surface, the pain would come back in a few minutes, and I’d soak it again.

    – Finally went to bed with 1 more benedryl and a lortab for the pain.

    Upon waking up this morning, the pain is greatly subsided. Still feel noticeably woozy and weak, but that’s par for the course for my system following an acute anything; wasp sting, severe migraine headache, and now puss caterpillar.

    Lessons learned and I’ll be better prepared next time. And remember kids: “If it doesn’t stick ya, prick ya, sting ya or bite ya, it doesn’t belong in Arizona.” Best to leave that interesting looking little cotton ball creature alone!



    Thanks for the excellent report. Sorry about the pain, but glad you used the tape, as that seems to work better than anything else.

    Keep us posted.


  23. Mary Wood Oct 4,2011 11:12 am


    – Though I felt considerably better the next day, it took a full 24-36 hours to feel completely recovered.

    – Surprisingly, the sting site never showed much in the way of redness or bumps. Only a tiny bit but if you didn’t know it was there, I doubt anyone would notice.

    – For several days the sting site did feel like the skin was dried and deadened. There was some peeling.

    But otherwise, all better now and thanks to this site, much better equipped to deal with the next puss caterpillar I cross paths with!


  24. Pingback: The Most Surreal Insect on Earth

  25. almaroche Nov 13,2011 4:38 pm

    I think I found some of these caterpillars in my plants, some of them are in an orange tree and the biggest one is on an hibiscus I’m not sure though (could I post a picture?
    What do I do? Do I leave them there or should I get rid of them now that I know they’re poisonous?


  26. livbellaluv Nov 17,2011 8:34 pm

    My son was at his High school (in Palm Beach county)when he was stung by one of these nasty buggers. Thankfully, though he panicked, his school nurse looked up caterpillars and used tape right away, gave him some ice and called his Mamma. He’s still complaining tonight..which is how I found this site..

    What a great site..wonderful information. I am making poultices of ginger and potato, hopefully this will help.
    I’ll be giving some information..gathered here…to the school tomorrow.

    Thank You!!!


    We’re glad the information posted here was useful. Please keep us posted on how your son is doing.


  27. ak019983 Apr 30,2012 11:04 pm

    I was just Googling around when something reminded me of the stings I got as a kid growing up in Clearwater FL. I’m 46 now and live in the North East and i still remember the 2 different occasions I was stung but good by those little buggers. Both times I remember, the caterpillars were on an oak tree I was climbing, and I remember going to the hospital, being given Benadryl, and the hospital staff not really knowing what was going on. I was told I was probably having an allergic reaction to a bug bite, but that was 30+ years ago. I remember coming home after the hospital visit and toughing it out for hours and hours with burning and pain at the sting and lymph node pain, nausea, dizzyness. My parents

  28. ak019983 Apr 30,2012 11:17 pm

    I pushed submit accidentally, sorry! Anyway, my parents didn’t know what was going on either. I think it should be more common knowledge about these caterpillars, I remember the experience as pretty extreme, and i was a pretty tough kid. I decided to post because I saw on a site (at least according to the site) that reports of stings in Florida only began about 20 years ago. They were there way before that, but nobody knew what they were. Thanks

  29. tabhoneycutt Sep 7,2012 8:41 pm

    I was stung this week twice by this critter. I live in North Carolina but have never seen anything like this. I went to my doctor with pain from the stings and was treated with an antibiotic. I had searched the internet and could not determine what this critter was. I knew it looked like a “furry caterpillar”. My doctor and all the other physicians at the clinic did not know what it was either. I am glad to know what it is from this site and that it can not be deadly or too dangerous, although the pain from their stings is terrible!

    Thank you for all the information on this site.

  30. Julie Apr 11,2013 5:33 am

    Just stung on vacation in Puerto Rico the first week of April. Very scary. Stung at elbow, horrible pain and blistering skin at elbow with numbness radiating up to armpit. So relieved to read no long term effects. It is one week later, though, and I am itching intensely at sting site???

  31. Marie Rose May 23,2013 8:35 pm

    On Feb. 29, 2012 I was bitten by an asp caterpillar with serious poisoning that lasted for a few weeks and then off and on symptoms. I have an autoimmune disorder that seemed to create havoc in my system with finally seeing an infectious disease doctor in April 2013 who could see that things had not cleared up as I had watery blisters by the bite area with deep itching where the bites were located. I was doing quite well until I was bitten by this horrid creature.

    Has any research been done on those of us with autoimmune disorders? Long term effects in these cases? I believe that this critter put me backwards and so did my primary care doctor and the infectious disease doctor when I told him the story. He put me on a Lyme type medication which dried up the watery blisters and the deep itching.

    Please contact me about this as I want to know more.
    Thank you

  32. Marie Rose May 23,2013 8:37 pm

    I was stung on Feb. 29, 2012 with being seriously poisoned for a few weeks. I could feel the poisons in my brain and elsewhere. As of this year, 2013, I had some watery blisters appear by the bite area and deep itching so saw a infectious disease specialist who immediately put me on a Lyme disease type medication which after three weeks seemed to dry up the watery blisters and the deep itching that was right below the bite area. I have an autoimmune disorder so am wondering if any research has been done on those of us who are more inclined to have difficulties with a long term problem after being bitten.

    Prior to the bites i had stabalized my system to the point where foods were not such a major issue, more energy and all but after the bites I went backwards very quickly.

    Please let me know what has been discovered or what research is being done. I live in California but was bitten in Mesa, AZ while sleeping in a very clean house.

    Thank you,
    Marie Rose

  33. Michelle Jun 26,2013 5:14 pm

    I got stung today in Weirsdale, FL. Leaned on one full force on a fence. Burned like fire and my muscles started hurting. I was stung on my forearm and the pain radiated down first and then up with sometimes tingling fingers and a muscle spasm or two. First thing I grabbed was some hand santizer that I keep in my car then I tried a tobacco poultice since I was not near anything else and had no signal at the time to look anything up. My coworker looked up caterpillars on his phone and we tried to figure it out on the way back. Tried tape and ice when we got to the office which helped a lot. Did some more tape and a tea bag poultice and that seemed to help too. I am still hurting 4 hours later but no other major symptoms than described by others. I’ll try the potato slice and ginger root next. The tea bag did seem to help some. I tried tobacco and tea bags as that is what my mom and grand parents used on bees and wasps stings when I was a kid to draw the stingers out and before I found this site.


    Michelle: let us know how the potato and ginger poultice works for you. Others have reported good results, but it appears your tobacco and tea bag poultices have had good results, too.


  34. Kristy Jul 24,2013 4:01 pm

    I got stung by a puss caterpillar about a week ago. I saw it on my skin and flicked it away. I did not think too much more about it until hours later when the burning was getting progressively worse and pains were shooting up and down my arm. Although I only saw the caterpillar for a second, I was able to ID it from the pattern on my arm. Once I found out what it was, I used tape to remove the stingers.
    It has been about 8 days since the sting and most of the burning and shooting pains have stopped by now, but it is beginning to itch a lot and the area around the sting still looks very swollen. It is also becoming more bruised looking. Is it normal for the venom to affect someone this long?


    Kristy: Different people react differently to the puss caterpillar’s sting. My suspicion is that several of the spines are still in your skin. Many people report that continuing to use tape to remove the remaining spines, even days or weeks after the sting occurs, is a great help.

  35. Faith Sep 8,2013 1:09 am

    I live in Maryland. I am very concerned after reading all about these things. I wanted to know if it is a nation wide thing or if they are in a general area. I love caterpillars and so do my children. I do not want to have one of them get stung one day not know what it is. If they are in any region of Maryland, please let me know. I am in Southern Maryland to be exact.

    Thank you in advance,

  36. Marsha Bradley Sep 8,2013 12:23 pm

    Is this the same as a packsaddle? My parents used to talk about stinging caterpillars but called them packsaddles.

  37. Murray Sep 8,2013 5:50 pm

    Long term effects??
    Hi all,
    My wife had a pus caterpiller land on her neck several years ago. She swatted at it, probably burying the spines even more. Being Canadian tourists we didn’t know anything about the problem – certainly not how to get out the spines.
    Now She has re-curring severe muscle pain in the area of her neck where the caterpiler landed. This happens about twice per year.
    Has anyone else had this longer term effect?

  38. crystal Sep 9,2013 9:43 am

    My son got stung yesterday by one of these. He is four years old and was screaming so hard i thought is arm was broken. his arm brushed up against it and fortunately he was able to tell us it was a caterpillar then identify a picture we showed him on the website. He was inconsolible and writhing in pain for nearly two ours. we taped with scotch tape after about 10 or 15 minutes, then again with duct tape after about 30 minutes. we immediately gave him ibuprofin and beynadryl after about 30 minutes. it was the hardest thing my husband and i have ever been through to watch our child suffer so much and be able to do nothing about it and the worst two hours of our son’s life. I actually drove him halfway to the ER twice because his pain was not subsiding, but ended up turning around due to getting advice to adminster benadryl, and then my son finally starting to calm down. Thank you for this website. Things could have been much worse for our son and us had we not been able to identify the caterpillar and leran that it was non-life threatning and how to treat and remove the stingers.

  39. Jennifer Sep 9,2013 10:47 am

    I got stung by one of these when I was around 8 or 9 in South Carolina. I remember it being a little white fuzzy thing. It was under a leaf on my Mom’s rubber tree and I guess I rubbed against it while moving the plant. It hurt like heck!! Worse than a bee sting!! Had a welt come up almost immediately. My Mom just made a paste of aspirin, baking soda, and cold cream and applied it to the area. It worked to lessen the pain and took the swelling down but was really sore for a few days. Ever since then I avoided anything fuzzy!! By the way that paste works really well on bee stings. I know I got slathered in it a lot as a child! Yellow jackets are no joke! Especially when you are trying to steal pears out of their tree!! LOL

  40. Rebecca Mills Sep 10,2013 1:19 am

    We live in North Eastern Az. and Our property is covered with these black long haired fuzzy catterpillars, my two year old is always playing outside with one of us and likes them, or atleast she likes to get close to them and check them out,do you know which kind they are? I figured they have got to be just the normal everyday harmless ones because there are just so many.

  41. Betty Lustila Sep 10,2013 5:04 am

    Are these nasty little things just in the Florida area or is there a map of where they are found. I’m in the Upper Peninsula of Michigan.

  42. Lenny Williamson Sep 10,2013 8:39 am

    I see most of the questions and testimonials come from the Southern states.How far North are these little monsters found?

  43. miller Sep 10,2013 10:47 am

    Are thay in canada

  44. miller Sep 10,2013 10:48 am

    Are thay in CANADA ONTARIO

  45. Frances Sep 10,2013 1:32 pm

    I was stung by one of these in 1966 as I was bringing in the wash off the line. I still remember the pain that travelled up my arm to my neck and chest. It hurt for days and left a scar that remained for years. In Texas, they called it a “possum worm” as well as an asp.

  46. Jean Frederick Sep 10,2013 5:53 pm

    Are these found all over the country or prevalent to certain areas? I live in North Dakota and never heard of them, are there any reports of them being here? I would assume the winters would be to cold for them to lay their eggs here but then monarch’s are here.

  47. Vickie Smith Sep 10,2013 6:30 pm

    Since I have grandkids, I am concerned about this caterpillar. I have noticed most of them have been in the southern part of the United States. Have there been any in Illinois?

  48. lynnette Sep 10,2013 7:46 pm

    I was stung by one of these last year it was on the arm of my chair but curled in a ball my arm was numb but luckily I felt none of the other symptoms just the pain on my arm I used an after bite patch it did help but it was sore for a few days

  49. Todd Sep 10,2013 8:45 pm

    I was wondering what states are they mostly located in?

  50. Rebecca Jackson me Sep 10,2013 11:32 pm

    Was wondering where these caterpillar are at. I am in Illinois

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