Classical Biological Control for the Management of Alien Invasive Plants in Ireland

As a consequence of the sustained interest in exotic plants we now face the challenge of dealing with the economic and ecological impacts of many environmental weeds. Exotic ornamental plants can often flourish as they have been imported without their natural enemies that suppress the plant’s growth and reproduction in the native range. The aim of classical biological control is to re-establish the natural regulation provided by host-specific primary consumers from the native range of the weed. In contrast to the long history of arthropod biological control in Europe, environmental weed biological control is only now gaining some momentum. Ireland stands to benefit from developments made in other EU member states and other parts of the world as it shares many of the same environmental weed problems. Both terrestrial and aquatic weeds are good targets for biological control, and developments relevant to Ireland are described in this paper to illustrate the potential benefits of this management option.