Box Tree moth (Cydalima perstectalis)

The Box Tree moth (Cydalima perspectalis) has a wingspan of c 40mm and is a member of the large Pyralidae moth family.

Box Moth ( Cydalima perspectalis)  photo Andrew Jones
Box Moth ( Cydalima perspectalis) photo Andrew Jones

The species is better known for the defoliation its caterpillars cause to Box hedging and trees (Buxus). Brown expanses of once green box hedging has become an increasing sight in many gardens in the south east of England.

Although in continental Europe the moth has long been considered a major pest it is only in recent years the species has begun to colonise the south east of England.

The moths spread has been rapid with records now reaching the western counties. Andrew Jones recorded the adult shown left in his garden in Portishead on the outskirts of Bristol in 2018.

Migration and the importing of eggs on plants and climate change are thought to be the reasons for its arrival and expansion.

Box Tree caterpillar

Box moth caterpillar recorded on outskirts of Paris by Gillian Caw
Cydalima perspectalis moth caterpillar recorded in London  photo © P. Brevitt
Cydalima perspectalis moth caterpillar recorded in London photo © P. Brevitt

Large batches of eggs are laid on the larval foodplant which then overwinter.

The fully grown Box Tree caterpillar is approximately 30 mm in length.

The caterpillars hatch in the Spring and may soon become an infestation, completely defoliating large expanses of box hedging.

When fully grown or running out of food the caterpillars often wander in search of somewhere to pupate or a new food source

Other caterpillars can be seen in the –

Moth caterpillar gallery and species pages

Butterfly caterpillar gallery and species pages

Caterpillar vegetable pests

Hairy caterpillars

Box Tree Hedging defoliated by Box Tree caterpillars, Cydalima perspectalis, in London.
Box Tree Hedging defoliated by Box Tree caterpillars, Cydalima perspectalis, in London – sighting Sally Hopgood.