Diagnosing and Treating Aphid Honeydew on Chinese Elm

Symptoms

Shiny, sticky leaves and drippings = aphid honeydew. Sooty mold may follow. Ants often tend aphids.

Treatment Hierarchy

1. Check for natural predators (ladybugs, lacewings, parasitic wasps).
2. Control ants (sticky bands, sprays) to allow biological control.
3. Systemic insecticides (acephate/Orthene, imidacloprid/Bayer Advanced, dimethoate/Cygon) for best leaf-penetration.
4. Soil-applied systemics (imidacloprid drench) for season-long control.

Key Takeaway

Start with least-toxic options. Systemics are most effective for established aphid infestations on large trees.