Scale Insects on Japanese Maple
How to identify and get rid of scale insects on Japanese Maple. Size: 1–5mm.
Identifying scale insects on Japanese Maple
Small brown or grey shell-like bumps along branches and twigs, particularly on the smooth bark young Japanese Maples are known for.
Life cycle
Crawlers emerge from under scale and disperse. Settled scales are immobile under protective shell.
Damage to Japanese Maple
Scale insects sap-suck along branches, weakening growth and causing dieback in heavily infested twigs, with honeydew that can attract sooty mould and detract from the tree's ornamental bark.
How to treat scale insects on Japanese Maple
Apply horticultural oil during the dormant winter season when the tree is bare, which smothers overwintering scale without harming the tree.
Preventing scale insects on Japanese Maple
Inspect branches during winter when scale is easiest to spot against the tree's smooth bark, and prune out heavily infested branches.