Are Spiny Caterpillars Poisonous?

Also called the puss caterpillar, asp, woolly slug, or “possum bug”, this caterpillar has venomous spines hidden in the hairs (setae) on its body. When picked up, these spines deliver a powerful and painful sting. ... Some folks experience swelling, nausea, abdominal pain, headache, even shock and respiratory distress.

Are spiny caterpillars dangerous?

One species, the spiny elm caterpillar (larva of the mourning cloak butterfly), is reported to possess venomous spines. ... Larvae feed on foliage of elm, cottonwood, hackberry, and willow. The chances of running into these insects are relatively low, but occasionally one species may be very abundant.

What happens if you touch a spiky caterpillar?

It is thought that exposure to the creature's tiny hairs, called setae, triggers an overactive immune response in some people. Touching a caterpillar can cause redness, swelling, itching, rash, welts, and small, fluid-filled sacs called vesicles. There may also be a burning or stinging sensation.