Boxwood Psyllid
Psylla buxi (Linnaeus), Psyllidae, HEMIPTERA


DESCRIPTION

Adult -This small (3-mm-long), grayish-green sucking insect has transparent wings and resembles a miniature cicada (Color Plate 2N).

Egg - The tiny, orange egg is spindle shaped.

Nymph- The flat, green- and brown-mottled nymph is covered with whitish, waxy filaments. The nymph is wingless and smaller than the adult (Color Plate 20).


BIOLOGY

Distribution -Boxwood psyllids seem to occur wherever boxwoods are grown. In the United States, however, they are most common in temperate areas.

Host Plants - Boxwood is the only known host of this pest. Although both American and English varieties are attacked, American boxwoods are more likely to be severely infested.

Damage - Psyllid nymphs extract sap from buds and young foliage. As a result, terminal leaves of infested plants become cupped and twig growth may be checked (Color Plate 2P). Since the boxwood psyllid completes its single annual generation early in the growing season, plants tend to outgrow their injury by midsummer.

Life History - Boxwood psyllids overwinter as firstinstar nymphs still within their orange egg shells. In spring as buds begin to grow and leaves unfold, the nymphs hatch from the eggs. They immediately begin to suck sap from new leaves. As their feeding causes leaves to curl, the nymphs become concealed and protected. After developing through several instars, psyllid nymphs molt into adults in May or early June. Although adults continue to feed, they are not as damaging as nymphs. In July or August, female adults deposit one to seven eggs under each bud scale. First-instar nymphs develop within the egg before winter but do not emerge until spring. Only one generation occurs each year.


CONTROL

Insecticides are available for control of boxwood psyllids. Infested plants should be treated when new growth appears, and applications should be repeated as necessary. For specific chemical controls, see the current state extension service recommendations. .

Return to AG-189 Table of Contents