Clematis vitalba is a fast-growing vine that produces vast quantities of seeds and grows intensely as thickets over trees, shrubs and other vegetation. Due to its rapid growth rate and ability to form large clumps, the plant can quickly outcompete native biodiversity and is dangerous to forests which is why Clematis vitalba is classed as one of New Zealand’s most invasive alien plants. Current control methods include mechanical removal and herbicides. However, this project is investigating the potential of biological control using fungi from its native range to help control the weed.
Lesser calamint is an aromatic perennial herb that has been introduced to New Zealand from Europe. Currently present on the east coast of the North Island, lesser calamint is considered an emerging weed; it is affecting desirable pasture species and having negative economic impacts. CABI is conducting field surveys and searching for natural enemies from lesser calamints area of origin in Europe that could be introduced in New Zealand as biological control agents.
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.
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.