What's eating my washington hawthorn?

Washington Hawthorn is attacked by hawthorn lace bugs (causing silvery, stippled foliage), cedar-hawthorn rust (orange galls), aphids clustering on new growth, and leaf miners. Birds target the berries in autumn but this is beneficial dispersal, not damage. The biggest nuisance is lace bug, especially in hot, dry summers.

Upper leaf surface looks silvery or bleached with tiny stippling; undersides show brown excrement and cast skins. Blast undersides with a strong water jet early in the season; apply insecticidal soap or neem oil at first sign; ensure good airflow and avoid moisture stress, which worsens infestations.

Curled, distorted shoot tips and sticky honeydew leading to sooty mould on leaves. Introduce or encourage ladybirds and lacewings; knock aphids off with water; apply insecticidal soap or neem oil spray if colonies are heavy.

Bright orange-yellow spots on upper leaf surfaces in spring; lesions may develop hair-like tubes on the underside; premature leaf drop. Remove nearby Eastern red cedar (Juniperus virginiana) where practical; rake and dispose of fallen leaves; apply preventive fungicide (myclobutanil or sulfur) from bud break through spring.

Pale, blotchy or serpentine trails visible through the leaf, causing cosmetic disfigurement but rarely killing the tree. Crush mined leaves between fingers to kill larvae; remove heavily mined leaves; no insecticide is usually warranted on established trees.