There is still some doubt as to whether this taxon and the two which follow, Y. malinellus and Y. cagnella are separate species or merely subspecies which have taken to feeding on different plants. Y. padella differs from the other two in that it is usually noticeably smaller and grey in ground colour, and in our opinion should be treated as a good species. Its caterpillars feed chiefly on hawthorn although sometimes silken webs of about 40 individuals therein may also be found on blackthorn, plum or cherry. Widespread and very common in vc 66, usually on the wing a week or two later than [Yponomeuta] evonmella. [...]