Box tree moth

What you see

Green caterpillars with black stripes and white dots, inside dense webbing among box foliage. The adult moth is white with a broad brown border.

Damage

Webbing among the leaves, then rapid browning and skeletonising from the inside of the bush outward - damage is often well advanced before it shows on the surface.

Lifecycle on this coast

Two or three generations a year, overwintering as small caterpillars in webbed shelters within the bush.

When to act

Zero tolerance on box hedging - a plant can be destroyed in a single season. Check inside the bush monthly, not just the outside.

Months: April, May, June, July, August, September, October

Plants it bothers

Box

Natural enemies

Blue tit, Wasp, Bat

Remedies

Bacillus thuringiensis (Bt), Pheromone traps

The thing people get wrong

Part the foliage and look INSIDE the bush from April. By the time browning shows on the outer surface the caterpillars have usually been feeding for weeks. Bt sprayed into the heart of the bush at the first webbing works beautifully - and does nothing to bees, which matters because box is a nectar source.