Biological control of Himalayan balsam
Himalayan balsam has rapidly become one of the UK’s most invasive weed species. A lack of natural enemies allows it to successfully compete with native plants for space, light, nutrients and pollinators, reducing biodiversity and contributing to erosion. Traditional control methods are inadequate. This project involves identifying an insect or plant pathogen that exclusively attacks Himalayan balsam, which can be released into the UK to control the plant while leaving indigenous species intact.
Controlling wild ginger
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.
Azolla control
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.
Locating a biological control for tutsan in New Zealand
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.
Controlling noxious Russian knapweed in North America
Russian knapweed is one of several invasive plants of rangelands that arrived in North America as a seed contaminant in the 19th century, in this case from Asia. Biological control is often a good approach for these plants, but a nematode species introduced in the 1970s proved ineffective against Russian knapweed. Funded by a US and Canadian consortium, CABI has been tasked with researching new biological control agents for introduction, some of which are already showing promise.
Biological control of brown marmorated stink bug
International trade is a common way for insects to ‘hitch-hike’ their way to new countries. The brown marmorated stink bug, originally from East Asia, has become a harmful invasive pest of many fruit and vegetable crops in North America and Europe. Biological control using Asian or European natural enemies may be an environmentally friendly, cost-effective and sustainable way of managing the pest. CABI is drawing on its network of expertise in Europe and China to explore best options.