Scientists fight back against a silent invasion

Experts are on the lookout for alien pests like this Leopard Gecko Thomas Ziegler

They may be small, but pests and pathogens from abroad - such as the Asian longhorned beetle - can cause huge damage to the ecosystem within Europe. In Switzerland, a new top-level plant protection lab should allow researchers to get to know the “enemy” better.

This content was published on February 17, 2015 - 11:00
Isobel Leybold-Johnson in Birmensdorf,

Located near Zurich, in Birmensdorf, the Swiss Plant Protection LaboratoryExternal link at the Federal Institute for Forest, Snow and Landscape Research (WSL)External link is a level 3 laboratory – the highest biosafety level for non-human pathogens - and only one of a few of its kind in Europe. went for a closer look.

Although inaugurated in October 2014External link, the CHF15 million ($14.7 million) lab complex will officially open for business at some point in the first half of 2015, says WSL deputy director Christoph Hegg, standing in the timber-covered building’s entrance on a bright winter’s day.

This is because the strict safety measures for level 3 labs have to be approved first. “We have to show that we can contain everything we bring in here. So if you work with a pathogen in a lab we have to show that we are able to completely clean any living particle from this lab,” he explains.

Level 3 pathogens and pests, like the aforementioned beetle, are quarantine organisms that have either not yet reached Switzerland or have only occurred locally.

Beetle-shaped priority

“The Asian longhorned beetleExternal link might become a priority because we are facing major outbreaks in Switzerland and we need to have more knowledge about this insect, how it behaves and in particular, which tree species are being attacked by it,” joins in Daniel Rigling, the scientist who will lead the lab. “These types of experiments can be done in a safe environment here.”

The highly destructive wood-boring Asian beetle has already been spotted in Switzerland. In 2012, for example, it appeared in Winterthur after hitching a lift on a delivery of granite in wooden packaging material from Asia. More than 100 trees were felled due to proven or suspected presence of the insect. The cost of this action and continued monitoring: several million Swiss francs.

Another worry is the fungal-like pathogen Phytophthora ramorumExternal link, which has been found in several plant nurseries and gardens across the country. Rigling and his team will be looking at which native tree species are at risk.

As we move into the heart of the building, to which workmen are still applying the finishing touches, we pass through the level 2 labs for quarantine organisms, such as chestnut blightExternal link, which are already established in parts of Switzerland.

Invasion of the small

“Invasive species have been on the rise in Switzerland over the past 20 years,” says Hegg, explaining the need for the lab facility. This is mainly the result of international trade, human mobility and global warming.

Domestic flora cannot always fight off the intruder, as was the case with chestnut blight,  which originated in Asia and was the first major epidemic of an introduced pathogen in the US and Europe. And it is not only trees that suffer, Rigling says. Overall biodiversity is also at risk. “Every tree harbours a number of other associated organisms, so if a tree species is being removed from the forest by an introduced pathogen, the associated species will be threatened too.”

Luckily, so far no major introduced pest or pathogen has targeted beech or Norway spruce, the main tree species in Switzerland, he added.

Safety first

Safety measures are thus in place for level 2 organisms, but they are reinforced further for level 3. This includes having negative air pressure in the laboratories, filtering the extracted air, using reinforced glass, and autoclaving - where the temperature reaches 120 degrees Celsius to kill off any living organisms - any waste material and used water. In addition, the level 3 labs can only be reached through an airlock. On the other side, we can see the locker area where the lab researchers will get changed into their protective suits.

“The suits are not primarily to protect ourselves from pathogens but to protect against people bringing any contamination out,” Rigling says.

Face masks won’t be worn, like for Ebola, a level 4 pathogen that is deadly to humans, because plant pests and pathogens don’t pose any risk to people, he explained. Overall there will be around 20-25 people working in the building, but only 4-5 researchers will receive the required safety training for level 3 labs.

Greenhouse “core”

Next up, and through another airlock, is the greenhouse, “the core of level 3 facility”. “The risk for an escape of a harmful organism is highest here because here we are performing experiments with these organisms and plants in a relatively free environment,” says Rigling.

Although empty now, in a few months the greenhouse will be bustling with scientists looking at which plant species are the most vulnerable to certain insects, fungi and nematodes (threadworms).

The last section of the greenhouse is for insects, which will be kept in additional caves inside the rooms, “so they will not be flying around”, Hegg says. Scientists are planning to study their biology and to learn how best to control them. This knowledge can then be passed on to the forestry services and Swiss authorities.


The WSL has been involved in the diagnostics of forest pests and pathogens for a long time. But there are hopes the new, bigger facility - co-funded by the Federal Office for the Environment External linkand the Federal Office for Agriculture,External link which are also active in the plant protection field - will speed up their work.

“We also hope that we can do a  lot of interesting scientific experiments and gain a lot of scientific experience that can be useful for Switzerland, the rest of Europe and beyond,” adds Hegg.

And, of course, both men are hoping that the situation develops in such a way that the level 3 labs are not in constant demand. Or as Hegg puts it, “we are not overwhelmed with invasive organisms in Switzerland”.

‘Urgent need’

The Swiss Plant Protection Laboratory at the Federal Institute for Forest, Snow and Landscape Research (WSL) was officially opened on October 20, 2014 by the education and research minister, Johann Schneider-Ammann. He stressed that the country urgently needed the level 3 facility for plant pests and pathogens.

It is the last in a series built by the government to study harmful pathogens and thus joins the federal biosafety laboratories in Spiez for human pathogens and at the Institute of Virology and Immunology in Mittelhäusern for animal pathogens.

There are an estimated 107 invasive species in Switzerland.

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