This is one of four Ermine moth species, namely Orchard Ermine (Yponomeuta padella), Apple Ermine (Yponomeuta malinellus), Spindle Ermine (Yponomeuta cagnagella) and Willow Ermine (Yponomeuta rorrella) which should now be recorded as Yponomeuta agg., unless it is made clear that they were recorded as an occupied larval web or reared from the relevant larval foodplant. Adults cannot be reliably identified unless raised from a larval web on the relevant foodplant.

Other similar Yponomeuta species also use Spindle, so if recording smaller webs the larval differences between cagnagella/plumbella/irrorella need to be checked (see 'Further Information' links below).

Adult

Larval web

Prefers chalk or limestone districts.

July and August

The food plant is Spindle the larvae feeding gregariously in a silken web.

Fairly common throughout Britain except in the far north. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as common.

Frequent in Leicestershire and Rutland.

Yponomeuta irrorella - LepiWiki (in German)

Yponomeuta plumbella Larva comparison with Y. cagnagella | UKmoths