This story was first published on September 8, 2014
Reports circulating via social media warn people not to touch the ‘Puss Caterpillar’ because its fur contains venom that can cause intense pain as well as vomiting and other health problems.
The claims in the reports are true. Puss caterpillars (Megalopyge opercularis) have venomous spines under their fur that can break off and embed in your skin if you touch them. The venom can indeed cause intense pain as well as headaches, nausea, vomiting, and other health issues. The caterpillars can be found throughout the southern United States, Mexico, and parts of Central America.
Update: October 2020
Warning messages about puss caterpillars are once again gaining momentum on social media. Recent news articles report multiple sightings of the toxic little critters in eastern Virginia. This is unusual.
An October 8, 2020, CNN report notes about the Virginia sightings:
The caterpillar isn’t commonly found in the state. Sightings are more likely farther south, in states like Texas, or in midwestern states like Missouri, according to researchers. No one is entirely sure why there have been so many recent reports in Virginia.
One Richmond, Virginia resident reportedly ended up at the ER after an unfortunate encounter with one of the caterpillars.
The Virginia Department of Forestry has issued a warning about puss caterpillars via its Facebook Page:
Florida scientists: Don’t touch this bug
As far as bugs go, caterpillars are usually pretty tame – except for one.
Reports Warn About Touching Furry ‘Puss’ Caterpillars
Various messages currently circulating via social media warn users not to touch furry ‘puss’ caterpillars because their fur contains venom that can cause intense pain. The messages link back to longer news reports discussing the dangers of touching these bugs.
Given the seemingly endless parade of fake-news reports that have been distributed via social media in recent months, it is understandable that some recipients have questioned the veracity of the caterpillar stories.
Claims in Reports Are True
However, the reports are genuine and the claims about puss caterpillars are true. Touching a puss caterpillar (Megalopyge opercularis) can indeed cause intense pain and other health issues. An article about the caterpillars on the scientific and medical society website AACC explains:
Megalopyge opercularis, commonly known in Texas as an “asp” is one of the most toxic caterpillars in North America. Also known as puss moth caterpillars, the larva are teardrop shaped from 1 to 1.5 inches long. Although called a stinging caterpillar, the venom is actually in spines connected to a poison sac and concealed by the outer hairy surface. When touched they break off and remain in the skin releasing the venom. Intense throbbing pain develops within five minutes of contact with pain extending up the affected arm. Other symptoms may include headaches, nausea, vomiting, intense abdominal distress, lymphadenopathy, lymphadenitis, and sometimes shock or respiratory stress.
The caterpillars can be found on various species of shrubs and trees. They range throughout the southern United States as well as Mexico, and parts of Central America. The soft and furry appearance of the caterpillars may give the illusion that they are harmless.
Of course, puss caterpillars are not the only type of caterpillar that can cause pain and other health issues when touched. Many types of caterpillars around the world can cause such reactions. In fact, Lonomia oblique, a species found in South American rainforests, can cause internal haemorrhaging and even death.
However, puss caterpillars are certainly one of the most toxic found in North America.
Treating Puss Caterpillar Stings
Experts recommend that adhesive tape be used to remove the venomous spines from the skin. You should also wash the affected area with soap and water to remove any surface venom. Applying an ice pack and a baking soda poultice may help combat pain and reduce swelling.
If more serious symptoms are present, you should seek medical advice as soon as possible.