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.
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.
Rev. 2020