Saddleback Caterpillars: Watch Out for that Sting

Source(s): Randy Drinkard

Over the past several weeks I have been contacted by several community gardeners who have discovered saddleback caterpillars by feeling their painful sting. I was stung by one years ago while harvesting okra. It literally knocked me to the ground. To avoid more gardening mishaps with these creatures I want to share this article written by Randy Drinkard. Stay safe out there gardeners!

Most people know that bees, wasps, hornets and some ants can sting to defend themselves or their nests. Only a few people realize, usually from first hand experience, that handling some caterpillars can produce some painful results. Recognizing the few stinging caterpillar species, including the saddleback, may prevent irritating encounters.

Saddleback Caterpillar

Saddleback Caterpillar Description

The saddleback caterpillar measures about an inch long, and has poisonous spines on four large projections (tubercles) and many smaller ones projecting from the sides of its body. The “saddle” consists of an oval purplish-brown spot in the middle of a green patch on the back.

The saddleback caterpillar is a general feeder and is generally found on many hosts including corn foliage, apple, pear, cherry, rose, Pawpaw, basswood, chestnut, oak, plum and other trees in late summer.

Diagnosing and Treating Stings

Diagnosis is usually simple since a rash generally breaks out where the hairs or spines have made skin contact. Contacting the hollow poisonous hairs or spines (connected to underlying poison glands) causes a burning sensation and inflammation that can be as painful as a bee sting. The irritation can last for a day or two and may be accompanied by nausea during the first few hours. Usually the site of contact reddens and swells much like a bee sting.

Immediate application and repeated stripping with adhesive or transparent tape over the sting site may be helpful in removing broken hairs or spines. Washing the affected skin area thoroughly with soap and water may help remove irritating venom. Prompt application of an ice pack and a baking soda poultice should help reduce pain and swelling. Household analgesics, such as aspirin, appear to be ineffective for reducing pain and headache. However, oral administration of antihistamines may help relieve itching and burning. Topical corticosteriods may reduce the intensity of inflammatory reaction. Desoximetasone gel applied twice daily to affected areas may also help. Prompt referral to and treatment by a physician should be made when severe reactions are evident. Very young, aged or unhealthy persons are more likely to suffer severe reaction symptoms.

Sting Prevention

Occasionally, these stinging hair caterpillars may drop out of trees onto people, crawl into clothing on the ground, occur on outdoor furniture or sting when brushed against on plant foliage. Be careful when attempting to brush them off. Never swat or crush by hand. Remove them carefully and slowly with a stick or other object.

Individuals, especially children, should be cautioned about handling or playing with any colorful, hairy-like, fuzzy caterpillars since it is sometimes difficult to distinguish between harmless and venomous insect larvae. Never handpick these hairy, fuzzy or spiny caterpillars except with heavy leather gloves if necessary. Wear long sleeve shirts, trousers and gloves when harvesting sweet corn or working in the landscape in late-summer and early-autumn to reduce possible stings.

Chemical Control

Usually, these stinging hair caterpillars do not occur in sufficient numbers to warrant the use of pesticide sprays. Should potential hazards exist around residences or schools, infested shrubs and trees may be sprayed to reduce or eliminate these caterpillars. Sprays of carbaryl (Sevin), or Bacillus thuringiensis (Biotrol WP, Sok-bt, or Thuricide) as well as various pyrethroids (bifenthrin, cyfluthrin, cypermethrin, deltamethrin, lambda-cyhalothin, permethrin and tralomethrin) in formulations labeled for bushes, shrubs and trees, can be helpful, if practical. Be sure to read the label, follow directions and safety precautions.


Insect Pests of Ornamental Plants

Center Publication Number: 200

Randy Drinkard
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20 thoughts on “Saddleback Caterpillars: Watch Out for that Sting”

  1. My wife was stung today by a saddleback caterpillar, which we had never seen or heard of before. We captured it and put it in a jar. We immediately identified it by Googling images for ‘stinging caterpillar’. Of all the hits we got when we Googled ‘saddleback caterpillar sting treatment’ (or something like that), yours was the very best and most helpful. Good work!

  2. Hi, my mom lives in Atco NJ, so far we found two saddle caterpillars in her yard…I’m reading different sites and looks like there just starting to be found here in Jersey. They hurt bad

  3. Stung today on the legs. It was on a hydrangea behind the house. Like stepping in a red ant bed, but you can’t stop the burning. Took 4 Benadryl, used tape, bathed, and applied baking soda. It was scary.

  4. Stung yesterday in Georgia, little fella’s were on the under side of a blue berry leaf. Talk about hurt! Thought I’d been stung by a bee until I saw the little hairs.

  5. A few years ago I was pulling out old corn stalks in the yard , no gloves. I was reaching for a stalk …..and there was a saddleback. Fortunately I did not grab it. It is a pretty fellow and I took some pictures. I notice from comments they seem to appear in August -Sept. Let’s be careful. Good site. Thank you.

  6. Bingo! Adhesive tape, soap and water, baking soda poultice, and Benadryl toned down my sting. Add blueberry bushes to the list.

  7. I accidentally touched a Saddleback caterpillar today and lemme tell ya folks- they are no joke! Worse than any sting, cut or burn I’ve ever felt. I guess because they have so many ‘stingers’, it got me multiple places on FOUR fingers! Water definitely makes it worse, same with ice. When you enlarge a decent pic of one, AS you’re feeling the pain? Yes- they DO appear pure evil! Lol. Beautiful creature otherwise. ;-p

  8. Fifty-four years ago my mother encountered this little horned beast while picking corn in our family garden. She had a severe allergic reaction, going into anaphylactic shock, nearly dying. Dad had farmed all his life and never seen one around here. We named them “pack saddle bugs” because they appeared to be packing a saddle. Also put several into glass jars and took into town for identification. No one in the farm or feed stores had seen there before.

  9. i live in Tennessee got stung by one yesterday it burn really bad not my first time it lasted about hour got light headed other than that I was fine

  10. Thank you for the excellent article which I truly needed after being stung on the arm. Didn’t see the caterpillar under a leaf on a plant in Puerto Vallarta, Mexico and brushed up against it. WOW! red hot pokers. I ran water on it, applied Listerine mouth wash and then found your article. I used the tape and baking soda and 1/2 hour later there are still welts and it is still stinging! Going to go get an anti-histamine. Thank you for the wonderful advice.

  11. Found one in McIntosh County , Georgia. Did not touch, but took a picture. Thanks for all of the information. I am over sixty years old and have never seen one of these insects in this area.

  12. I got stung by one this morning when cutting glads. I have been gardening here for 40 years, and this is the first I’ve seen. Upper Bucks County PA Thanks for posting this info, I popped two Benedryl immediately as I am deathly allergic to hornets, etc. All’s well, but I will watch out for more!

  13. Oh my God, yes!!! I put my hand on my fence, right on one of those. It was soooooo painful. It dropped me to my knees. Lasted for hours. Avoid
    At All Costs, Be Aware!! I’m in Florida. And so are they!!

  14. Just got stung in Milton, GA. They were on my Triostar Stromanthe plant on my porch! Reached in to pull some dead leaves and felt a quick sting, then saw these “creatures” on my plant leaves—they blended in with the plant colors. Lived in various states and, in my 64 years, never saw or heard of this caterpillar before. Happy for the information above to help soothe my arm. OUCH!!

  15. Stung twice by one of these crazy looking caterpillars. Once it was underneath tomato plant leaf, and another time it moved nearby to basil plant a few days later. Both times felt the stinging not knowing why and then discovered it later. Stamford, Connecticut


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