Friday, April 25, 2025

Creepy ‘bone collector’ caterpillar adorns itself with the corpses of its victims while residing in a spider web and living in a very small habitat

Amazing stuff!

"a newly discovered Hawaiian caterpillar, described recently in Science, which exclusively resides on spiderwebs hidden inside logs and rocky crevices. While most caterpillars feed on plants, these carnivorous critters scavenge for dead and dying insects that have become ensnared in the webbing—when they’re not cannibalizing each other, that is.  ...

To avoid becoming the spider’s next meal, the caterpillar—which scientists have nicknamed the “bone collector”—uses a gruesome camouflage technique straight out of The Silence of the Lambs, or possibly The Texas Chainsaw Massacre. After spinning a protective case of silk, it meticulously decorates itself with leftover insect body parts (including weevil heads, beetle abdomens, and fly wings), occasionally incorporating scraps of molted spider exoskeleton too. “There’s a spider web, and then next to it is basically a jumble of sewn-together bug parts ,” ...

Genetic analysis revealed that bone collector caterpillars, which are so rare that scientists have only observed 62 individuals over 20 years of fieldwork, diverged from their closest relatives more than 5 million years ago—making this lineage older than the island it currently inhabits. ..."

From the editor's summary and abstract:
"Editor’s summary
The vast majority of lepidopteran caterpillars are herbivorous. Those that break this rule tend to do so in unexpected ways, such as the Hawaiian inchworm, an ambush predator. Rubinoff et al. describe another unusual caterpillar, also from Hawaii, that scavenges discarded insect parts. The “bone collector” lives in spider webs and feeds on the discarded bits of the spider’s insect prey. Perhaps to avoid detection, these caterpillars construct portable cocoons decorated with inedible discarded parts. This species is 5 million years older than the oldest Hawaiian island but is now highly endangered, being found in only a single population on Oʻahu. ...

Abstract
Lepidoptera is the most herbivorous of all the insect orders, with predatory caterpillars globally comprising less than 0.13% of the nearly 200,000 moth and butterfly species.
Here, we report a species in which caterpillars are carnivorous inhabitants of spider’s webs, feeding on the arthropods that they find there. This Hawaiian lineage also boasts an unprecedented and macabre practice of decorating its portable larval home with the body parts of the spider prey it harvests from the web where it resides.
Phylogenomic data suggest that the origin of this unique spider cohabitant is at least six million years old, more than one million years older than Hawaii’s current high islands.
After decades of searching, only one species has been discovered, and it is restricted to 15 square kilometers of a single mountain range on the island of Oʻahu, meaning that other members of the lineage have disappeared from older islands. Conservation action to save this globally unique lineage is imperative and overdue."

ScienceAdviser



A newly discovered caterpillar weaves the remains of insect prey onto a protective case (several shown) worn for camouflage, a new study suggests.


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