What's eating my european hornbeam?

European Hornbeam (Carpinus betulus) is most troubled by aphids — especially the hornbeam woolly aphid — which cluster on new growth in spring. Scale insects, caterpillars of various moths, and leaf-mining caterpillars also cause damage. Deer and rabbits may browse young trees or strip bark in winter when other food is scarce.

Sticky honeydew and sooty mould on leaves; distorted young shoots; white waxy coating on colonies Blast off with a strong jet of water; apply insecticidal soap or neem oil to young colonies; encourage natural predators such as ladybirds and lacewings

Pale, blister-like or serpentine mines visible through upper leaf surface; leaves may brown and drop early Remove and destroy heavily mined leaves; avoid broad-spectrum insecticides to protect parasitic wasps that naturally control populations

Waxy brown or white bumps on stems and undersides of leaves; yellowing foliage and honeydew deposits Scrub crawlers off with a soft brush dipped in soapy water; apply horticultural oil (winter wash) when dormant; use systemic insecticide for severe infestations

Bark stripped or frayed at the base in winter; young shoots and foliage browsed back hard, especially on bonsai specimens kept outdoors Fit tree guards or wire mesh around the trunk; use deer-repellent sprays (must be reapplied after rain); site bonsai on raised benches out of reach