Meet the creepy ‘bone collector’ caterpillar that wears its dead prey like armor

Bone collector caterpillars inhabit spider webs, scavenging leftovers from captured prey. (Image: Rubinoff lab, Entomology Section, University of Hawaii, Manoa)

Nature can be stranger than fiction, and Hawaii’s newest creepy discovery proves it once again. Scientists have identified a bizarre caterpillar that builds its home using the body parts of dead insects.

This carnivorous creature belongs to the Hyposmocoma genus and has earned the nickname “bone collector” for its eerie behaviour. Found only on a small mountainside in Oʻahu, this species has remained hidden for millions of years.

A Caterpillar That Hunts, Eats and Wears Bones
Unlike most caterpillars that munch on plants, this one prefers meat. It is both carnivorous and cannibalistic. Researchers say it feeds on other insects and even its own kind.

The caterpillar hunts by searching spider webs tucked under tree bark. It scavenges leftover bits from the spider’s meals. Using silk, it stitches together these insect parts to build a protective case.

Entomologist Daniel Rubinoff from the University of Hawaiʻi at Mānoa led the research. He admitted the discovery was hard to believe at first. “I thought it was a mistake,” Rubinoff said. “Even now, it still blows my mind.”

Although some may find it gross, Rubinoff admits it has a certain charm. “They’re like, ‘I’ll eat some of this and wear the rest,’” he joked.

Decorate or Die: A Strange Survival Strategy
When fully grown, the caterpillar transforms into a moth, leaving behind its grisly disguise. But before that, it passes the behaviour to its offspring by laying eggs inside a spiderweb.

Once hatched, the young caterpillar immediately begins gathering insect bones. This gruesome armour helps it blend into the spider’s web both by look and smell. It’s a clever way to avoid becoming dinner itself.

Scientists found that when placed in a lab, these caterpillars refused to use twigs, leaves or bark. Only insect remains were acceptable for their strange fashion choice.

Although they steal from spiders, researchers say they are not parasites. Instead, they are scavengers who mostly feed on leftovers. But if food runs low, they won’t hesitate to turn on each other.

One of Nature’s Rarest and Strangest Creatures
This insect is not only bizarre but also incredibly rare. Only 62 individuals have been spotted over two decades. Its limited habitat already places it on the endangered species list.

Akito Kawahara from the Florida Museum, who was not involved in the study, praised its adaptation. “Insects do everything. They are amazing,” he said. “Hawaii’s conditions lead to some truly strange behaviours.”

The Hyposmocoma genus itself is full of oddities. Some species eat snails; others live both underwater and on land. But none were known to wear the remains of their prey — until now.

The full study was published in the journal Science this April. Scientists hope it will raise awareness of Hawaii’s unique and fragile ecosystems, home to some of the world’s weirdest creatures.