CABI’s work on the biological control of invasive weeds making great progress

CABI’s work investigating how classical biological control methods can help in the fight against invasive weeds around the world is making excellent progress, according to a new report just published.

Scientists from CABI’s centre in Switzerland this year started two new projects – the biological control of black locust (Robinia pseudoacacia) for South Africa and a study of the drivers of invasion of cheatgrass (Bromus tectorum).

Progress on projects

Furthermore, some of the newer projects, including tree of heaven (Ailanthus altissima) and parrot’s feather (Myriophyllum aquaticum) in North America have gained traction and are making excellent progress.

Seventeen other projects are also making progress and include Japanese knotweed (Fallopia japonica) and Himalayan balsam (Impatiens glandulifera) work in the UK and Dalmatian and Yellow Toadflax (Linaria vulgaris) research in eastern Serbia.

Though the focus of CABI’s Swiss centre work on the classical biological control of invasive weeds remains North America, active biocontrol projects are also taking place in other countries such as Pakistan, South Africa, and Australia.

Insect, mite, and fungal control agents

CABI has over 60 years’ experience of working on the biological control of invasive weeds and is one of the few organisations in the world that can simultaneously research and develop insect, mite, and fungal control agents.

Any organism intended for the control of a non-native invasive plant undergoes an extensive series of tests to determine its environmental safety before considering its release. More than 50 biological control agents have been released based on the work carried out at CABI in Switzerland alone.

Many of these are currently contributing to the successful control of important North American weeds such as leafy spurge, toadflaxes, knapweeds, houndstongue, and purple loosestrife.

Successful control of important North American weeds

Following the publication of the ‘Weed Biological Control Progress Report 2023,’ Dr Philip Weyl, Head of Weed Biological Control, said 2023 has also been an exciting year so far with several new ‘agents’ making their new ‘homes’ abroad.

Dr Weyl said, ″The hoverfly, Cheilosia urbana, on hawkweeds was successfully sent with viable eggs arriving in both Canadian and US quarantine facilities. We were also able to send over the stem and rhizome feeding weevil Bagous nodulosus against flowering rush.

″The rhizome-feeding tortricid moth, Dichrorampha aeratana and the gall forming eriophyid mite, Aceria angustifoliae were both released in Canada this year against their hosts oxeye daisy and Russian olive respectively.

″It is testament to the team, their enthusiasm and dedication, for which I am grateful, that each of the research projects are making excellent progress.″

Hosting of several international collaborators

The Weed Biological Control Progress Report 2023 also highlights how CABI in Switzerland has been hosting several international collaborators this year.

These include Mikenna Smith from the Wyoming Weed and Pest Council (WWPC) which has partnered with CABI for more than 30 years to slow the spread of invasive species in Wyoming.

Meanwhile, Dr Natalie West (USDA-ARS Sidney MT) visited CABI in Switzerland to gain experience of working with the weevil Bagous nodulosus ahead of a possible release against flowering rush in the USA in the near future.

Furthermore, David Harris, a PhD student from SUNY ESF, New York State, came over to collect and learn about the defoliating beetle Chrysochus asclepiadeus against Swallow-worts in North America. Dr Peter Toth from the Slovak University of Agriculture in Nitra, Slovakia, also visited to work on field bindweed.

Expertise in the management of invasive species shared

Finally, CABI’s expertise in the management of invasive species was shared at the XVI International Symposium on Biological Control of Weeds (ISBCW) 2023 held in May for the first time in South America in Puerto Iguazú, Argentina.

Scientists from CABI’s centres in the UK and Switzerland took part in a range of workshops and sessions at the symposium where one of the objectives was to forge closer ties between South America and the rest of the international weed biocontrol community.

Weed Biological Control Progress Report 2023 >>