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Spindle Ermine Caterpillars
Like a horror story in your backyard
We spotted these caterpillars on a campsite we were staying at a few years ago. There were literally thousands of them hanging from the bushes at the entrance to the park. They are spindle ermine caterpillars, which have a habit of dropping from the sky and landing on whatever happens to be below them.
Some say they’re like something out of a horror story — others think they’re endearing. We found them fascinating. But to get a face full of caterpillars as you walk under a bush is not a great experience.
Spindle caterpillars drop on a silken thread as a defence mechanism against perceived threats, or when dispersing to find a new location to pupate. This behaviour, similar to spiderlings’ ballooning, allows them to safely lower themselves to the ground. They might be looking for a new feeding site, or to escape a disturbance, using the silk strand as a lifeline to be carried by the breeze or to simply get away from danger.
They might drop because they’ve been disturbed, or just to find new sources of food. I suspect much of the time it’s to find food and pupate, before they metamorphosize into moths.
On one occasion on the campsite, I was out enjoying the sun, walking in the breeze, when suddenly something wriggly landed in my hair…
