Boxwood psyllid Cacopsylla buxi
IDENTIFICATION – The boxwood psyllid is a small sucking insect that attacks tender young boxwood foliage as it emerges in spring. This stunts the growth of the shoots and causes the leaves to cup or curl and turn yellow. You may also find some white, waxy fibers around the curled leaves. Fortunately, this pest doesn’t usually cause serious damage to the plant.
LIFE CYCLE – In early summer, the adults appear and females begin laying eggs in the bud scales of the boxwoods. The eggs remain in the buds until the following spring when the nymphs emerge and begin feeding on the new growth. They use the curled leaves to conceal themselves while they continue growing and maturing. There is one generation of boxwood psyllid per year.
CONTROL – The damaged shoots and leaves are unsightly and can be pruned off to improve the appearance of the shrub. If the boxwood psyllid returns every year, spray them with horticultural oil or insecticidal soap each time they appear.