The most effective control is achieved with newer insecticides that also kill nymphs. Thorough coverage of the underside of leaves is essential. This treatment usually is repeated two or three times at weekly intervals. Psyllids are small soft-bodied insects related to aphids. Their hind legs are enlarged for jumping, giving rise to their common name, jumping plant lice.
Adults are winged and very active.
They move quickly when disturbed. Some species are serious pests, but many are simply nuisances because the honeydew they produce leads to unsightly crusts of black sooty mold. Boxwood psyllid is probably the most common boxwood pest in Virginia. Nymphs, covered with a white waxy material, feed on the terminal leaves as they unfold in the spring. The familiar result is stunted twigs and cupped leaves.