What's eating my stewartia pseudocamellia?

Japanese stewartia is an unusually clean tree with very few serious pests. Scale insects occasionally colonise the attractive mottled bark, and spider mites may appear in hot, dry summers. Root weevil notching on leaves can occur. Keeping the tree in moist, slightly acidic, well-mulched soil is the best defence against all pest attack.

Waxy or cottony lumps on bark and stems; yellowing foliage; sticky honeydew; localised bark discolouration under heavy infestations Horticultural oil spray in late winter to smother overwintering stages; insecticidal soap for active crawlers in early summer; maintain vigour with consistent moisture

Fine stippling on leaves; bronzed or silvery upper surface; fine webbing on undersides in hot, dry conditions; leaf drop in severe cases Increase humidity and water regularly during drought; strong water spray to knock mites from leaves; neem oil or insecticidal soap; avoid broad-spectrum insecticides that kill predatory mites

Notched scallop-shaped bites around leaf margins from adult beetles at night; larvae in soil attack fine feeder roots on younger specimens Apply nematode soil drench (Steinernema kraussei) in late summer to kill larvae; check soil at roots if tree shows unexplained wilting; remove adults by hand-torching at night