What's eating my japanese maple 'crimson queen'?

Acer palmatum 'Crimson Queen' shares the same pest profile as other Japanese maples: aphids are the chief nuisance on tender new growth, with scale insects and gall mites as secondary threats. Its weeping, congested form can trap humidity, so watch also for caterpillars sheltering inside. Water-blasting and good air flow are first-line controls.

Cluster on unfurling spring leaves and shoot tips, causing sticky, curled, discoloured growth and honeydew that promotes sooty mould. Direct a strong water jet at infested shoots. Avoid oil-based sprays on Acer foliage. Encourage natural predators; remove and dispose of heavily infested tips.

Small waxy or cottony encrustations on bark; persistent feeding weakens branches and can cause dieback if left unchecked across multiple seasons. Horticultural oil applied in late winter smothers overwintering scales. A second spray targeting crawlers in late spring improves control. Prune out dead wood.

Various moth larvae feed on leaves, leaving ragged holes or, in severe cases, stripping entire shoots; the weeping habit provides shelter for larvae. Hand-pick larvae and egg masses. For larger infestations, spray with Bacillus thuringiensis (Bt) — effective and harmless to beneficial insects — when caterpillars are small.