What's eating my acer griseum?

Acer griseum (paperbark maple) is generally pest-resistant. Aphids can colonise young shoots and cause honeydew sooty mould on the peeling cinnamon bark. Scale insects occasionally encrust stems. Deer browse young specimens in rural settings. Aphids are the most commonly encountered pest and respond well to early treatment with insecticidal soap.

Colonies on new growth in spring; honeydew drips onto the decorative peeling bark and lower foliage, causing sooty mould Apply insecticidal soap or neem oil to affected shoots; knock off with a water jet; attract ladybirds and lacewings

Hard brown waxy bumps on young stems; sap drain reduces vigour; honeydew and sooty mould on bark Scrub off with soapy water and a soft brush; apply horticultural oil in late winter during dormancy

Bark stripping and shoot browsing on young trees in autumn and winter Fit a spiral tree guard or wire cage around the trunk; apply deer repellent in late autumn