Plants from the Hedychium genus are widely loved and cultivated as ornamentals but a few are threatening delicate ecosystems in Hawaii, New Zealand, the Macaronesian Archipelago (Azores, Madeira and the Canaries), Brazil, Australia and La Réunion. We are researching natural ways to manage the plants where they have become invasive, which involves returning to their original home range in the North eastern Himalayan foothills to try to find damaging and specific insects and/or pathogens which may prove suitable for release in the invaded range.
One of the UK’s most invasive plants, the fairy fern or floating water fern causes problems for anglers and water managers. It forms thick mats on the water’s surface which can double in size in a few days, blocking out light and killing aquatic flora and fish. Fragmentation of the fronds makes control by mechanical means virtually impossible. This project involves researching and testing the use of a 2mm-long North American weevil (Stenopelmus rufinasus) as an agent to control the weed naturally.
Tutsan, native to Europe, was introduced to New Zealand but is now a major invasive species. In 2011, CABI’s Swiss centre was approached by Landcare Research to investigate prospects for the biological control of tutsan. Surveys in the native range revealed a suite of insects and pathogens. CABI’s laboratories in the UK are currently conducting research on strains of the rust fungus, Melampsora hypericorum, from Europe to assess their potential to control tutsan populations in New Zealand.
The European earwig has become a considerable domestic and public nuisance in the Falkland Islands, causing significant problems for local horticulture by decimating many garden vegetable crops. This population explosion is due to the absence of natural enemies that would normally keep them under control. To try and find a solution to this problem, CABI is investigating the possibility of using two parasitic fly species to control the earwigs in a biological way.