22/05/2026
Somewhere in a British woodland right now, a tree has disappeared. 🌳
Not fallen, not felled, just quietly wrapped in silk, its leaves stripped bare, thousands of tiny caterpillars dangling on threads in the May light. If you have not seen it yet, keep walking. It is out there.
This is the work of the Spindle Ermine moth, and it is one of nature's more theatrical performances. The caterpillars hatch gregariously, which is the scientific word for deciding that there is safety in absolutely enormous numbers, and then collectively wrap their host tree in dense silk webbing that can cover every branch from top to bottom. The tree looks ghostly, otherworldly, and frankly a little alarming if you do not know what you are looking at.
RESTORE's Agata Rucin recently filmed exactly this in her local woodland, and it is the kind of thing that stops you mid-stride.
But here is the point - this is not a disaster. It is biology doing exactly what biology does. The tree will recover and the spectacle itself is a reminder of something we too easily forget: abundance matters. Not just species diversity, but the sheer volume of life. Tens of thousands of caterpillars on a single tree represent an enormous pulse of energy moving through the food web, sustaining insectivorous birds that time their breeding season around precisely this kind of seasonal glut, as well as parasitic wasps and other invertebrates that depend on it.
The ermine moth's strategy is a masterclass in evolutionary thinking. Being numerous is a liability if you are easy to pick off one by one, so the solution is to be numerous and hidden at the same time, wrapped in silk, moving together, overwhelming the odds.
This is happening across the country right now. Has anyone else spotted it near them? Drop a comment and let us know where. 🦋