A puss caterpillar feeds on a leaf. Photograph by George Grall, National Geographic. Young children from Florida to North Carolina are reporting excruciating pain after coming into contact with the most venomous caterpillar in the U.S., the furry puss caterpillar (Megalopyge opercularis), according to news reports. Some have petted the insect; others have been injured when the caterpillars fell onto them from trees.
The puss caterpillar got its name because it resembles a cuddly house cat, said University of Florida entomologist Don Hall. While these insects may look soft, their outer comb-over (which some have compared to a toupee or the coif of Donald Trump) hides small, extremely toxic spines that stick in your skin.
“A puss caterpillar sting feels like a bee sting, only worse. The pain immediately and rapidly gets worse after being stung, and can even make your bones hurt,” Hall said.
“How bad the sting hurts depends on where you get stung and how many spines are embedded in your skin. People who have been stung on the hand say the pain can radiate up to their shoulder and last for up to 12 hours,” Hall said.
Caterpillar Boom and Bust
This species naturally goes through boom-and-bust cycles, and populations can rise and fall dramatically based on weather, food availability, and the number of parasites around, Hall said.
Hall has been stung himself several times, mostly by young caterpillars that he’s raised in his garage—juveniles generally have fewer spines than older, fuzzier insects.
Although there are no defined medical procedures if you do get stung by a puss caterpillar, Hall recommends covering the area with cellophane tape and then ripping it off to remove any spines that remain in the wound, which will help decrease the pain.
While we’re on the subject, those spines don’t exist just to make us humans miserable: Female puss caterpillars use the spines to protect their eggs from ants and other predators.
Puss caterpillars have other quirks, too: They fling their poop away from their bodies. Hall believes that behavior prevents parasites from being attracted to the feces and potentially harming the caterpillars themselves.