Today 
The sap-feeding scale insect Unaspis euonymi is particularly attracted to Euomymus japonica, although it will feast on other evergreen euonymus too. The white males congregate on the leaves, but the brownish-black females live on the bark, making them hard to spot. Large numbers cause yellowing of the leaves, dieback and loss of vigour.
Solution
Organic
With light infestations, scrape off the scales by hand and dispose of them. For heavy infestations, prune out those branches that are badly affected. Spray with a plant oil wash in winter.
Chemical
Spray the young scales in mid-July and early September with a systemic insecticide containing imidacloprid or thiacloprid.
