Photo: Donald Hobern/Flickr
The caterpillar of the Uraba lugens moth earns the moniker “Mad Hatterpillar” because it stacks the heads of its moulted exoskeletons into a fascinating headgear.
During its caterpillar phase, the Uraba lugens caterpillar moulds up to 13 times, however it does not lose all of its former body parts. It fashions a tower-shaped headdress out of part of the empty shells that originally housed its head. As the caterpillar develops, so does its head, and each empty shell on top of its head becomes larger than the one before it. When it moulds, the head section of its exoskeleton remains attached to its body, providing the animal a distinct appearance as well as a useful decoy in the event of an attack.
The Uraba lugens caterpillar, which is native to Australia and New Zealand, stacks its moulted heads into a towering edifice that can reach 12mm in height, or half of its body length. Most of the smaller heads fall off the caterpillar’s body over time, but it’s not uncommon to find caterpillars with at least five old heads stacked on top of each other.
Scientists believe that the odd stacked-head hat’s principal purpose is to protect the caterpillar’s true body from predators. One idea holds that it makes the creature appear more frightening than it is, while another holds that the former heads just give a misleading target in the event of an attack.
“They appear larger, therefore they appear more frightening and formidable to a possible predator,” Alan Henderson, wildlife manager of Minibeast Wildlife, told CNN. “Another argument is that it may create a misleading target, causing a predator, such as a jumping spider or something targeting a section of the animal, to go after the wrong part.” It provides the caterpillar with an opportunity to flee.”
Because of its voracious hunger, the Uraba lugens caterpillar is also known as the “gum-leaf skeletoniser.” Caterpillar armies will descend on eucalyptus trees, consuming the sensitive sections of the leaves and leaving only the scavenged skeleton of veins and stems that are too tough for them to bite and chew.