Did you know famous gardens such as Versailles are attacked by invasive alien species?

At this time of year, you may notice bare branches and white webbing on box hedges and trees. These are tell-tale signs that an invasive alien species, the box tree moth* has taken up residence. They were unintentionally imported to Europe on box plants from Asia. Box tree moth caterpillars can defoliate and even kill carefully tended trees and hedges in just a few days. This does not only damage private gardens, but also iconic hedges found in gardens like Versailles [1], or indeed in Tervuren Park near Brussels!

Invasive alien species can also attack crops grown by farmers, reducing yields and quality. For example, the Western Corn Root Worm† was accidentally introduced to Europe from North America [2] and quickly spread throughout central and western Europe. Their larvae feed on maize roots, damaging the crop and reducing yields. Each year, adult can fly and colonize new areas of farmland, up to 60km away. Practices such as crop rotation, innovative crop protection products and new resistant varieties can help farmers reduce or avoid yield losses and limit their spread.

Box tree moth invasion of Europe. Article written by M. J. Skvarla, published by Penn State Extension (2020) and based on the work of Bras et al. (2019) & European Boxwood and Topiary Society (2020).

* Cydalima perspectalis
† Diabrotica virgifera virgifera
1. Les buis du château de Versailles sous étroite surveillance - Le Parisien
2. Multiple Transatlantic Introductions of the Western Corn Rootworm | Science (sciencemag.org)