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. A single insecticide spray will prevent this damage, but it must be applied before injury is visible when new growth has just started in the spring.