Spindle Ermine Yponomeuta cagnagella
Wingspan 19-26 mm.
Very similar to several other Yponomeuta species, some sources suggest it can be distinguished by the pure white terminal cilia on the forewings, as opposed to greyish for other species. However, this is not a reliable feature and the only way to positively make an identification is by rearing from the foodplant, or by DNA analysis.
It is fairly common throughout Britain except in the far north, occupying chalk or limestone districts.
The foodplant, as the vernacular name suggests, is spindle (Euonymus europaeus), the larvae feeding gregariously in a silken web. Occasionally entire bushes or sections of hedgerows are taken over by the larvae and their web, causing defoliation.