What's eating my siberian elm bonsai?

Siberian Elm is among the most pest-susceptible elms, particularly to elm leaf beetles and aphids. Beetles and larvae can skeletonize foliage rapidly in summer. Aphids cause heavy, sticky infestations in humid weather. Elm leaf miners create distinctive brown blotch mines. Monitor closely from bud-break through summer.

Adults chew leaf holes in spring; larvae devour leaf parenchyma leaving only veins intact, turning foliage brown Remove egg clusters from leaf undersides; apply neem oil or pyrethrin spray when larvae are young; repeat after rain

Heavy colonies on new growth; sticky honeydew coating, sooty mold, and leaf distortion — particularly severe in humid summers Dislodge with a strong water jet; treat with insecticidal soap or neem oil; encourage natural predators; check weekly in spring

Brown blotch mines between leaf surfaces, with larvae feeding inside the leaf tissue from late spring onwards Remove and destroy mined leaves promptly; systemic insecticide (imidacloprid) can protect new growth on valued specimens

Small pouch-like or blister galls on leaf surfaces; cosmetically disfiguring but rarely life-threatening to a healthy tree Spray bare branches with winter wash (lime sulphur diluted 1:25) before bud-break to reduce overwintering mite populations