Euonymus Scale (Unaspis euonymi)
Covers of adult females are about 1/8 inch long, brownish black, and are oyster shell shaped. Male covers are smaller, thinner, and white. Crawlers are yellowish orange and are most often found on new growth. Fertilized adult females overwinter. There are four overlapping generations a year.
Light infestations on bark cause no obvious damage. In heavy infestations, the white covers of males are easy to spot on the leaves and the leaves develop yellow spots.
Always examine Euonymus japonica to discover infestations before they cause damage. Carefully examine bark on a few stems to detect light infestations. Examine plants for presence of predators and parasites.
Time application of horticultural oil, insecticidal soaps, or other contact insecticides for the presence of crawlers.