This unique crystalline caterpillar truly catches the eye, but dangerous barbs make for looking only.
The spun glass caterpillar Isochaetes beutenmuelleri is a member of the slug moth family and persists throughout much of the United States. It boasts a nearly transparent, glassy body core inset with extensions covered in dozens of dazzling crystal green barbs. More than a dozen tentacle-like appendages give the caterpillar a curious squid resemblance, which is emphasized by slow, circular, slug-like movements across a silky slime residue.
Although they appear beautiful, these creatures are extremely deadly. Touching their barbs results in skin penetration, an excruciating sting, and subsequent raging dermatitis. These caterpillars also exude poison from their spiky prickles, making for formidable opponents to humans and predators alike.
Spun glass caterpillars feed on the foliage of swamp oak trees, and though native to much of the United States, their numbers are few and encounters are rare. The caterpillars’ exquisitely radiant beauty only lasts for a short time, however.
The most interesting aspect of spun glass caterpillars is their transformation. From glimmering, glowing gems they mutate into plain, dull brown moths. While as larvae the caterpillars could have been strung together and draped like sparkling tinsel around a Christmas tree, in adulthood they fly under the radar, completely unnoticed.
The adult moths remain small, with a wingspan averaging 19–24 mm. For the rest of their lives, their most distinctive color marking is a circular brown spot near the tips of their wings.