What's eating my prunus padus?

Prunus padus (bird cherry) is heavily targeted by bird cherry ermine moth, whose caterpillars can cover entire trees in silk webbing and defoliate them by early summer. Aphids and cherry blackfly are regular visitors. Despite dramatic defoliation, healthy trees usually refoliate — ermine moth is the most alarming and common threat.

Larvae spin dense white silk tents over entire branches and defoliate trees completely by June; trees look dead but recover. Remove silk tents and larvae by hand on small trees. Natural parasitoids usually control populations within a season. No spray usually needed.

Black colonies tightly curl shoot-tip leaves in spring, checking new growth and leaving honeydew residue across foliage. Insecticidal soap or neem oil spray on affected tips; foster predator populations by avoiding broad-spectrum insecticides.

Early spring larvae eat opening buds and leaf tissue, causing holed, frass-covered foliage alongside the developing blossom. Grease bands on trunk in autumn; pyrethrin or spinosad spray for active caterpillars in April.