- adults: tiny, 1/8 – 5/16 inch long; delicate, lacy wings held flat over the back; flat appearance
- nymphs: smaller, typically darker with spines on the body; body is rounded or flattened
- eggs: cylindrical, black and laid in evenly spaced clusters on the undersides of leaves
Host Plants, Diet & Damage
- primarily oak, chokecherry and sycamore in Utah; apple, ash, California lilac, poplar, firethorn, willow
- feed on sap from the undersides of leaves
- cause yellow to white stippling or spots and interveinal necrosis visible on the top of leaf
- damage resembles that of spider mites and leafhoppers
- undersides of leaves appear dirty; adults, nymphs, eggs and shed skins present
- infestations on oak can cause leaf necrosis and leaf drop
- leave black, varnish-like fecal spots on leaf undersides
Biology, Life Cycle & Damaging Life Stage
- overwinter as adults on or near host plants
- fly to expanding host foliage in spring to feed
- adults lay eggs on the undersides of host leaves
- nymphs and adults feed on the undersides of leaves
- two or more generations per year; overlapping life stages present
- Manage trees to improve or maintain health.
- Damage is primarily an aesthetic issue; tolerate pest.
- Apply an insecticide (carbamate; horticultural oil, insecticidal soap, neem oil, neonicitinoid (soil systemic); pyrethroids; spinosad) to the undersides of leaves.