Pest identification
What's eating my japanese hornbeam?
Aphids
Signs: Clusters of small insects on new shoots; honeydew and sooty mould blacken foliage; shoot tips curl and distort
Control: Knock off with a water jet; apply insecticidal soap or neem oil; introduce or encourage ladybirds, hoverflies, and lacewings
Moth caterpillars (various, including Operophtera winter moth)
Signs: Ragged holes in leaves or complete skeletonisation; silk webbing may be visible; defoliation in heavy years
Control: Fit grease bands around trunks in autumn to trap wingless female winter moths; hand-pick caterpillars; use Bacillus thuringiensis (Bt) spray for large outbreaks
Scale insects
Signs: Crusty or waxy bumps along stems; sticky leaf surfaces; dieback in severe cases
Control: Horticultural oil (winter wash); scrape off with a soft toothbrush; systemic insecticide on badly infested bonsai
Keep japanese hornbeam pest-free
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Japanese Hornbeam pests — FAQ
What is eating my japanese hornbeam?
Japanese Hornbeam (Carpinus japonica) faces similar threats to its European cousin: aphids are the most frequent nuisance, colonising soft spring growth. Caterpillars of various moths skeletonise or mine the ornamental serrated leaves. Scale insects appear on weakened trees, and slugs and snails may graze on seedlings and small bonsai.
How do I get rid of aphids on japanese hornbeam?
Clusters of small insects on new shoots; honeydew and sooty mould blacken foliage; shoot tips curl and distort Knock off with a water jet; apply insecticidal soap or neem oil; introduce or encourage ladybirds, hoverflies, and lacewings
How do I get rid of moth caterpillars (various, including operophtera winter moth) on japanese hornbeam?
Ragged holes in leaves or complete skeletonisation; silk webbing may be visible; defoliation in heavy years Fit grease bands around trunks in autumn to trap wingless female winter moths; hand-pick caterpillars; use Bacillus thuringiensis (Bt) spray for large outbreaks
How do I get rid of scale insects on japanese hornbeam?
Crusty or waxy bumps along stems; sticky leaf surfaces; dieback in severe cases Horticultural oil (winter wash); scrape off with a soft toothbrush; systemic insecticide on badly infested bonsai