Boxwood Psyllid - Shrubs

Boxwood psyllid damage (cupping of leaves)

Key Points

• 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.
• 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.

Psyllid nymphs with wax

 Boxwood psyllid adult

Management

• This pest causes aesthetic damage to American and English boxwood. Prune out and dispose of infested branch tips. Sprays are only necessary if infestations are heavy. 

• 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.

Additional Resources

• Boxwood: Preventing and Managing Common Pests and Diseases
• The American Boxwood Society

Rev. 2020