The Bone Collector

Beyond Hawaii’s beautiful beaches lies a creepy caterpillar that camouflages itself with the body parts of other insects. 

Scientists recently discovered this creature, a species of carnivorous caterpillar located in the Waianae Mountains on the island of Oahu, which they dubbed “the bone collector.” 

Researchers Dan Rubinoff and his team explained that the aptly-named bug lives in spider webs and feeds on the remains of the arachnid’s prey.  

But to avoid becoming a snack itself, the caterpillar collects the body parts of other bugs – fly wings, earwig abdomens, and weevil heads, to name a few – and decorates their portable, silken cocoons with them. 

The researchers described in their paper that the larvae were very attentive in creating their macabre cases: They would measure and nibble on the body parts to get them down to size before using them. 

This behavior was “a decorate or die situation,” Rubinoff told Science News, adding that such a shield would protect a caterpillar from a spider’s fangs. 

The “bone collector” is one of the first known caterpillar species that lives directly in a spider’s hunting ground and exhibits this gruesome behavior. 

The team explained that the caterpillar is a member of the Hawaiian Fancy Case Caterpillar group. Its lineage dates back at least six million years, making it far older than any of the current islands of Hawaii. 

“The bone collector caterpillar is another example of how incredible and unpredictable evolution in Hawaii can be,” Rubinoff said in a statement. “Not only are they the only caterpillars in the world to decorate their homes with body parts but maybe more shocking, they make their living hanging around spider webs. This is something we never even imagined was possible. But in Hawaii, here it is.” 

However, the study found that the species is endangered and has only been spotted in a 5.8-square-mile area of forest in the Waianae Mountains. 

Rubinoff and others are now calling for habitat protection to allow the wacky species to thrive. 

“I’m really glad we discovered it before it went extinct,” he added.