University of Maryland Extension

Boxwood Psyllid - Shrubs

puckered leaves on boxwood
Boxwood psyllid damage

Return to Common Problems of Trees and Shrubs

The boxwood psyllid, Psylla buxi, causes a characteristic cupping of the leaves on the terminal and lateral buds of boxwood. This insect can overwinter as an egg, or as a first instar nymph under the bud scales. As the buds develop in the spring, the eggs hatch and nymphs emerge to infest the leaves. The feeding causes the leaves to curl and form a cup which encloses the greenish colored nymphs.

boxwood psyllid nymphs with wax
Photo: Psyllid nymphs with wax

The nymphs produce a white, waxy secretion which may cover part of the body or small waxy pellets beside the nymphs. The greenish adults emerge late May into June, mate and lay eggs under the bud scales. Only one generation occurs each year. This pest causes aesthetic damage to American boxwood and English boxwood.

close up boxwood psyllid adult
Photo: Boxwood psyllid adult

Management: Boxwood psyllid nymphs may be controlled with horticultural oil, or insecticidal soap sprays in April and May. Adults may be controlled by a registered residual insecticide in late May into June. Sprays are only necessary if infestations are heavy.


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