Orchard Ermine Yponomeuta padella
The Orchard Ermine is a typical Ermine: white with a lot of small black dots. It does come however in two flavours: entirely white, or white with a greyish shade, especially in the central part of the wing and near the tip of the wing. Only the latter variation can be named. The white animals are extremely similar to the Apple Ermine and the Spindle Ermine. You can not tell those white animals apart bij looking at them. Even examining the genitals often does not give a satisfying answer to the question which species you are looking at. They are still under investigation. They all could be one and the same species, but possibly it is a complex of species. So only the greyish species can be named as the other two species never come in shades of grey. The Orchard Ermine reaches a wing span of 19 to 22 mm.
The adults deposit the eggs in summer in groups of some 50 pieces. Such a group is covered in a shield of yellowish slime. Once that dries up, it is waterproof. The caterpillars appear in August and September, but many of them remain inactive behind their shield. In this way they overwinter. In April they appear. They spin a sliken web and live in that, sometimes in great numbers. They eat the fresh leaves and flower buds and may cause considerable damage. It is found on many plants, but especially on hawthorn, blackthorn, cherry and plumb. They may measure up to 22 mm. Pupation takes a short time only and adult moths appear from mid-June to mid-August. Even though they may appear in great numbers, there are never as many as Bird-cherry Ermines.
This is a fairly common species all over Britain. Common on the continent as well. Has been introduced in Northern America where it is considered an invasive species. Is also known as the Cherry Ermine.