Box Tree Moth is an invasive moth that lays eggs on exclusively boxwood plants. It is my understanding that this moth was introduced through the nursery trade into Canada and then it has spread from there parts of northern United States. it can kill your boxwood plants, and some people have lost entire hedges. Monitor your boxwood hedges for signs of an insect eating the leaves. If you find defoliation like this, start flipping the leaves over looking for the caterpillar. Then contact a certifie