The most painful caterpillar sting comes from the puss caterpillar in your southern states. This fuzzy creature looks soft and harmless to you. It hides venomous spines under that fluffy coat though. People who touch one feel an intense burning that spreads outward from the spot. The pain can last for hours and ruin your whole day. Don't let its cute look fool you at all.
If you've been reading about woolly bears, you can relax. Your woolly bear caterpillars are harmless to you. Their bristles are solid hairs that cause a mild itch at worst. The stinging caterpillar species that hurt you work through a very different setup inside their bodies. I first learned this when I held a woolly bear with zero problems. The next day I nearly touched a puss caterpillar on the same tree and caught myself just in time.
Stinging caterpillars carry hollow spines hooked up to venom sacs at their base. When you brush against these spines, they break off in your skin. Venom flows into the wound right away. Woolly bear bristles are solid all the way through with no venom sac attached to them. For you the difference is like comparing a needle to a strand of your hair.
The puss caterpillar sting tops the pain chart, but you should watch for other species too. Here are the worst ones you might run into near your home.
Puss Caterpillar
- Pain level: The worst of all for you, with victims comparing it to a broken bone or a hot coal pressed against your skin.
- Your symptoms: Burning pain, raised welts in a grid pattern, and pain that can spread to your lymph nodes over several hours.
- Where you'll find them: Common across your southern states from Virginia to Florida and west to Texas on shade trees and shrubs in your yard.
Saddleback Caterpillar
- Pain level: Sharp and fast, like pressing your hand against a cluster of thorns, with pain that fades after one to two hours for you.
- How you'll spot it: Bright green body with a brown saddle mark on its back and fleshy horns covered in spines that you can see up close.
- Your risk zone: Found across the eastern US on your garden plants, fruit trees, and shrubs from late summer through fall.
Io Moth Caterpillar
- Pain level: Causes intense itching and a burning rash on your skin that can last for several hours or even a full day for you.
- How you'll spot it: Bright green body with branching spines that look like tiny green sea urchins along every section of its body.
- Watch out: These caterpillars feed in groups on your trees, so touching one branch can put you near dozens of them at once.
If you get stung by any caterpillar, act fast. Press tape against your sting site and peel it off to pull out the spines. Do this several times with fresh tape each round. Then wash the area with soap and water. Put ice on it to cut the swelling down for yourself. Grab some cream from your medicine cabinet to help with the itch.
You should get to your doctor right away if the pain spreads past where you got stung. Watch for nausea or trouble breathing on your end. Look for swelling that moves toward your chest or throat since that needs fast attention from your medical team. Allergic reactions to the venom are rare but can get serious for you. Kids and people with insect allergies in your family should get checked out even for mild stings to stay safe. Your quick action makes all the difference in these cases.
Read the full article: Woolly Bear Caterpillar Facts and Guide
