The io moth used to be one of the most recognizable moths in the United States due to the conspicuous “eye-like” design on the moth’s wingspan. Today, this moth species is not nearly as prevalent in the US as it used to be, as their population has been declining in the northeast and the Gulf Coast regions since the 1970s. However, Louisiana is one exception, as io moth populations have remained largely stable in the state during the past several decades. Although io moths are interesting to look at, their larvae (caterpillars) possess protruding “spines,” similar to a porcupine. Unlike porcupines, the spines of io moth caterpillars are highly venomous, and the caterpillars are considered medically important insects. Generally, it is not common for people to sustain stings from io moth caterpillars due to their low populations in the eastern US, but stings still occur today in Louisiana where people encounter the caterpillars in their yards and gardens. After a Lake Charles man suffered an io moth caterpillar sting while performing yard work, he became determined to prevent other Louisiana residents from experiencing the same pain. So he decided to educate the public, particularly schools and daycares, about the danger posed by io moth caterpillars in residential areas.

Brian Hirsch sustained an io moth caterpillar sting after picking up a bundle of lawn waste that contained a few specimens. Unlike bees and wasps, simply making contact with many caterpillar species is enough to sustain a sting. The io moth caterpillar’s spines stick into the skin where they continue to release venom and cause excruciating pain. Pulling these spines out of skin with tape is recommended for those who sustain a caterpillar sting. Io moth caterpillars are not picky about the types of vegetation where they dwell, and their dark brown appearance allows specimens to remain camouflaged in foliage and lawn waste. These caterpillars breed rapidly too, as Hirsch pointed out a bush that was covered in io moth caterpillars despite being entirely free of the caterpillars two days prior. These caterpillars cause serious pain, and possibly serious allergic reactions, so being mindful while performing yard work will go a long way toward preventing io moth caterpillar stings.

Have you ever sustained a caterpillar sting?