Hawaiian caterpillar patrols spiderwebs camouflaged in insect prey’s body parts

Lepidoptera is the most herbivorous of all the insect orders with
predatory caterpillars globally comprising less than .13% of the nearly
200,000 moth and butterfly species. Here, we describe a species whose
caterpillars are carnivorous inhabitants of spider’s webs, feeding on
arthropods they find there. This Hawaiian lineage also boasts an
unprecedented and macabre practice of decorating its portable larval home
with the body parts of spider prey it harvests from the web where it
resides. Phylogenomic data suggests the origin of this unique spider
cohabitant is at least six million years old, over one million years older
than Hawaii’s current high islands. After decades of searching, only one
species has been discovered, restricted to 15 km2 on a single mountain
range on the island of Oʻahu, meaning other members of the lineage have
disappeared from older islands. Conservation action to save this globally
unique lineage is imperative and overdue.