There aren’t that many critters that make me cringe. Salties are powerful, worthy of respect, venomous snakes are definitely something to avoid, and huge Huntsman spiders are simply eight legged cheetahs with tiny fairy feet. Processionary caterpillars however, now they are an animal that keeps me awake at night!
These fluffy caterpillars are social insects, nesting together inside a silken bag that they weave into the branches of a tree. They are nocturnal, emerging at night to feed on the leaves of their host tree. If the caterpillars eat all the leaves on their tree they go walkabout in a giant conga line looking for another tree, leaving a silken trail as they go.
Scientists have worked out that a caterpillar will follow the twitching hairs on the rear end of the caterpillar in front of it, making the hairs a useful adaptation. They are also an important protective coat. Not many insectivores are equipped to deal with such an arsenal although the Crested Bell Bird has been known to paralyse the grubs by bending their backs and then using them to line their nest. Perhaps it keeps predators away from the chicks.
The hairs can cause a skin rash on people. Even siting your tent under the branches of a tree that contains a processionary caterpillar nest can cause problems. In particularly sensitive people, this rash lasts for months and can become infected and incredibly painful. I am one of these unfortunates and even though I know that it is usually the hairs on the dead larval skins and adult moths that cause the problems I still feel a powerful quivering when I spot these seemingly cuddly grubs.
In the deserts of Central Australia, the East Arrernte people use the processionary caterpillar conga line to predict the seasons, with the length of the line corresponding to the length of the winter. Processionary caterpillars also have medicinal uses. Once the moths have left the cocoons the bag can be cut open and layers of the old silk can be used as a wound dressing. It is important to remember that like all remedies this can be dangerous unless the material is prepared and used in exactly the right manner.
Processionary caterpillar, itchy grub or little fluffy ball of pain. Whatever you call it the processionary caterpillar is a fascinating, and fearsome, little Australian.