What's eating my american wisteria?

American wisteria is mainly targeted by aphids clustering on new growth, scale insects on woody stems, and long-horned borers tunneling into the trunk. Japanese beetles skeletonize foliage in summer. The plant is vigorous enough to tolerate light infestations, but borers on the main trunk are the most serious long-term threat.

Colonies of small soft insects on shoot tips and flower buds; sticky honeydew leads to sooty mold and distorted new growth. Knock off with a strong water spray; apply insecticidal soap or neem oil; encourage ladybirds and lacewings.

Waxy brown or white bumps on bark and stems; weakens plant and causes yellowing leaves and branch dieback. Scrub scales off with a stiff brush and horticultural oil in late winter; treat crawlers in spring with insecticidal soap.

Adults skeletonize leaves in midsummer, leaving a lacy brown skeleton; heavy infestations defoliate entire vines. Hand-pick early morning; use row cover on young plants; apply pyrethrin spray for heavy pressure; avoid pheromone traps near the plant.

Sawdust-like frass at the base or in crotches; tunnels weaken or girdle main stems causing sudden wilting of large sections. Prune and destroy infested wood promptly; keep vine vigorous with good watering; apply bark-penetrating insecticide only for severe cases.