Some of the world’s leading scientists in the field of alien invasive plants are to debate how best to tackle the scourge of a range of alien invasive plants – some of whose pollen can cause severe irritation in humans and threaten native ecosystems.

CABI is co-organising with the University of Fribourg, Switzerland, the XV International Symposium on Biological Control of Weeds in Engelberg, Switzerland, which, on Thursday 30 August 2018, will include a panel of experts who will discuss the extent of invasive plant problems in Switzerland and elsewhere in Europe and how to tackle the problem.

Europe is being invaded by weeds. Many of these invasive plant species are not native and have been moved from their area of origin. Without natural enemies these plants spread quickly, and, once out of control, they can damage ecosystems and even property.

The cost of this invasion for European citizens is large and alarming – invasive species are estimated to cost the EU around 12 billion Euros each year and weeds are a significant contributor.

Members of the media are invited to the panel (see full details of invite in notes to editors below) which will examine whether or not biological control is the best method to control Europe’s invasive alien weeds. The panel will outline various arguments before a discussion and the chance for media to ask their own questions.

The Symposium comes as alien invasive plants such as Ragweed are now in full season across Europe – including the northern parts of Switzerland – where its pollen can cause humans to suffer from an itchy throat, irritated eyes, headaches, a runny nose and sneezing.

Other weeds coming under scrutiny include Himalayan balsam, which colonises river banks and outcompetes native species, as well as the aquatic invasive Australian swamp stonecrop which forms dense mats that reduce biodiversity. Both of these have had biological control agents approved for release in the UK and will hopefully provide more sustainable and effective management in future.

The panel, which will be led by Sarah Pearson Perret – French secretary of Pro Natura, includes:

  • Dr Nicola Schönenberger, Consultant at INNOVABRIDGE Foundation, Switzerland: ‘The reality of alien, invasive plant problems in Switzerland.’
  • Dr Elizabete Marchante, University of Coimbra, Centre for Functional Ecology, Portugal: ‘The case of Acacia in Portugal and the first classical biocontrol release in continental Europe.’
  • Professor ChristophKĂĽffer, ETH, Zurich, Department of Environmental Systems Science, Switzerland: ‘Not all exotic plants cause problems; each case needs to be looked at individually.’
  • Dr Heinz MĂĽller Schärer, University of Fribourg, Departent of Biology, Switzerland: ‘Predicting outcomes of classical weed biocontrol and scope for basic research.’
  • Dr Richard Shaw, CABI UK: ‘Perceptions of classical weed biocontrol in Europe.’

Dr Hariet Hinz, CABI’s Country Director and Head of Weed Biological Control based at CABI’s Swiss centre in DelĂ©mont, is the coorganiser of the symposium which takes place at the hotel Bellevue-Terminus in Engelberg, Switzerland from 26 to 31 August 2018.

Dr Hinz said, ‘Although the biological control of weeds has been practiced for over 100 years, it is still a much neglected tool in managing alien invasive weeds, partly due to misconceptions about its safety, and partly due to a lack of regulations.

‘We’re looking forward to a lively and engaging debate on some very important issues that may ultimately have far-reaching impacts on how humans and native ecosystems interact and are impacted by alien invasive plant species.’

Dr MĂĽller Schärer, from the University of Fribourg, and who is coorganiser of the symposium, a panelist and keynote speaker at the event, said, ‘Biological invasions and their management offer a great natural laboratory for studying processes of basic ecology and evolution. Biological control using natural enemies from the country of origin often remains the only realistic, practical and affordable approach to reduce the impact of widely established, problematic plant invaders. The ongoing impact of an accidentally introduced beetle on highly allergenic Ambrosia has the potential to relieve millions of allergy sufferers in Europe and reducing health costs by Euro 1.7 billion per year.’

Notes to editors

Media invite to panel discussion and Q&A session

Journalists are invited to attend the panel discussion as part of the XV International Symposium on Biological Control of Weeds 2018

The panel discussion will take place at hotel Bellevue-Terminus, Bahnhofstrasse 10, CH-6390 Engelberg, Switzerland, from 5-6pm on Thursday 30 August 2018. Panel members will first outline their individual topics before a discussion and opportunity for members of the media to ask their own questions.

Please confirm your attendance by email by Tuesday 28 August 2018 to

Speaker biographies, statements and additional information

Speaker biographies, statements and additional information are available to download from Dropbox at:

Media contacts

For international

Wayne Coles, PR Manager, CABI, email: tel: +44 (0)1491 829395.

For Switzerland

Direct contacts in case of specific questions:

Prof. Dr. Heinz MĂĽller-Schärer, Universität Fribourg: 079 – 787 35 71

Dr. Urs Schaffner, CABI Delémont: 079 – 286 45 37

Dr. Hariet Hinz, CABI Delémont: 079 – 462 14 59

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