Boxwood psyllid: Appearance, Territory, Damage, and Life Cycle

Latin Name: Cacopsylla Buxui

Appearance: In various parts of Illinois, the boxwood psyllid, Psylla buxi, can be seen feeding on American boxwood. American boxwood is extremely vulnerable to attack, but English boxwood is less so.

Boxwood psyllids, also known as leaping plant lice, are little (1/16-inch) grayish-green insects with a white, waxy, filamentous secretion that partially covers the body and protects it from parasitoids and pest-control sprays. Winged adults emerge in late May and early June. They’ve been spotted flying over plants. Adults may bite people, although the bites are not dangerous. During the early summer, females place spindle-shaped orange eggs between or under bud scales. The egg of the boxwood psyllid survives the winter.

Hosts Plants: Boxwood psyllids appear to be present wherever boxwoods are planted. However, in the United States, they are more abundant in temperate climates. This pest’s sole known host is boxwood. Despite the fact that both American and English boxwoods are attacked, American boxwoods are more likely to be badly afflicted.

Territory: They are most common in temperate areas of the United States, although they may be found everywhere boxwoods are planted.

Damage Insect Cause: Feeding damage is visible because of leaf cupping produced by immature nymphs on host plants. Leaf cupping is caused by damage to leaf tissue as it develops in quickly expanding leaves. This species occasionally affects immature twig development.

Do nothing- Because psyllid damage is mostly cosmetic, small infestations will result in only scattered leaf cupping. Each spring, keep an eye on the numbers since they may add up over time. If possible, cut and kill infected tips holding nymphs before they mature and lay eggs in mid-May.

Insecticidal soap and summer horticultural oil are two low-impact solutions. Because they function by direct contact with the insects, they must be sprayed when new growth begins and require extensive spray coverage. There is no lingering impact. Check for live nymphs several days after treatment to determine whether they are still present, and treat again if required.

Life History and Habits: This species spends the winter as eggs. During the early summer, they are placed between the host plant’s bud scales. Eggs begin hatching as soon as buds bloom in early April. Young nymphs begin feeding immediately by sucking plant juices from fragile leaves. On growing leaves, little nymphs emerge. Cupped leaves form and numerous nymphs may be encased in a pocket of vegetation. By early June, nymphs have normally matured into adults. Females lay eggs after mating, which overwinter on the host plant. In Pennsylvania, one generation happens each year.