What phenomenon largely explains the rapid, unchecked population expansion of the box tree moth upon its introduction to Europe?

Answer

Enemy release

The moth arrived in Europe without its natural Asian enemies, a phenomenon known as 'enemy release,' which allowed its populations to expand unchecked by the predators that naturally contained them in their native range.

What phenomenon largely explains the rapid, unchecked population expansion of the box tree moth upon its introduction to Europe?
rarityinsectmothTreepest