What's eating my albizia julibrissin?

Albizia julibrissin (silk tree / mimosa) is most seriously threatened by mimosa webworm, which creates silken tents over leaflets and causes severe late-summer defoliation. Scale insects and spider mites also attack. The tree's invasive vigor means it recovers from defoliation, but webworm can make large specimens look unsightly by late summer.

Webbed-together leaflets forming dirty-grey tents across the canopy; larvae feed inside, leaving skeletonized brown leaflets. Apply Bt or spinosad spray when first webs appear in early summer; remove and destroy small webs by hand; second generation in late summer needs retreatment.

Cottony white masses or brown waxy bumps on stems and branches; sooty mold and branch dieback in heavy infestations. Horticultural oil in late winter; systemic soil-drench insecticide in spring to reach crawlers.

Fine stippling and yellowing of the small leaflets in hot, dry conditions; webbing visible on leaf undersides. Overhead irrigation to raise humidity; neem oil or miticide spray to undersides of affected foliage.