[F]irst discovered in Long Beach, California, in July 1984 ... the peppertree psyllid, Calophya schini ... is native to Peru, which is also the native home of the California pepper tree, Schinus rnolle ...

Damage is caused by the nymphal stage of the insect. Each nymph makes a deep pit in the leaflet, and several dozen pits may occur on the same leaflet. Pitting and nymphal development occur also on petioles, immature flower buds, slender green twiglets, and occasionally on heavier wood. The pitting and associated discoloration and distortion of leaflets and twiglets disfigure trees. High psyllid populations result in a grayish appearance of infested trees, followed by extensive foliage drop, particularly during the
winter and early spring before the new flush of foliage is produced.

Adult female psyllids deposit translucent white eggs, which darken before hatching, on several types of tender new growth of the pepper tree. Unexpanded leaves ... seem
to be the preferred site of egg-laying. On hatching, the nymphs settle on nearby plant growth. Of 170 nymphs found on 192 leaflets examined from 16 leaves, 55 percent were on the lower surface and 45 percent on the upper surface.