Once a year in late May the small group of Spindle bushes (Euonymus europaeus) on Larkhill, Formby change dramatically. Within a few days heathy-looking green bushes become covered from head to toe with a white shining gossamer web.

Spindle Ermine larvae create a protective cage from predation, primarily from birds and parasitic wasps. The threads also create a highway by which larvae can move from branch to branch without returning to the main stems. This year it was dramatic as behind the silky cage were probably over 3000 larvae munching away.

A few days later all the leaves had been eaten and only bare stems were left and the larvae were on the move, spinning threads, down which they abseiled hopefully to a lower branch in the search for food and also clambering over each other in their hundreds.

Three days later all was still, nothing moved, all 3,000 larvae dead, piled along the bare branches or swinging from their threads. Amongst them were around 20 pupae, easily enough to put the colony back on its feet next year. An example of Nature controlling nature.

One of the few caterpillars that successfully built a pupa (orange on the right) (Richard Walker)

Below is an archive image of adult moth that completes the lifecycle. Adults will emerge from the pupae over the Summer, lay their eggs on the bushes and start the cycle again.