Leaves at the shoot tip are cupped.   In late spring, flattened pale green insects and a white waxy substance are present.   There are several species of suckers or psyllid that can be encountered by bonsai growers.   They are sap sucking true bugs. Sucker feed at the shoot tips of plants in spring; a white waxy substance covering a droplet of liquid, excreted by box sucker nymphs, often spills from the cupped leaves leaving white waxy smears on foliage.   In April to May flattened, pale green, wingless nymphs live among the leaves at the shoot tips.   New shoot extension in spring are stunted and the cupped leaves at the shoot tips produce a cabbage-like appearance.   Pesticide sprays are likely to be most effective when newly-hatched nymphs first appear on new growth in spring.   There is no point in spraying later in the year once the feeding damage has occurred.