About an hour outside of Vienna, the Penny Markt in Krems an der Donau prides itself on two things: low, low prices and the provenance of its meat and fresh produce. But on a mild August day last year, shoppers looking for a local bargain found a slightly more exotic, if less welcome, surprise among the crates of bananas.
The culprit was a stowaway, a Brazilian wandering spider, a 11-cm-long black and red arachnid whose bite causes convulsions, hypothermia, death and – if you’re male – particularly painful uncontrolled erections. You can imagine the shock.
The Shop closed for precautionary disinfection, and the spider escaped and was never heard from again. But it is not the only invasive creepy crawly that has found its way into European tabloids recently.
France has acquired an unfortunate reputation for rampant bed bug infestations ahead of the Olympic Games, with the deputy mayor of Paris, Emmanuel Grégoire warning People: “Nobody is safe. You can catch them anywhere,” and reports of the bloodsuckers on the Eurostar are causing panic in London.
Tiger mosquitoes, which can transmit dengue and Zika fever, have also been spotted across the country, prompting Paris authorities to call in entomologists. “Detectives” to locate their breeding grounds.
The Turkish pharmaceutical industry now generally sees Europe as an exciting new export market for Scorpion antidote.
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Is climate change responsible for this apparent arthropod invasion?
The reality is less apocalyptic than the headlines suggest, says Dr Matt Green, senior entomologist at British global pest control company Rentokil Initial, which operates across the continent.
We are a long way from dengue becoming endemic. French bed bug reports have increased largely because people saw the horror headlines and started looking under their mattresses. And if we are seeing more invasive species in general, it is largely not due to rising temperatures.
“I’m often asked how climate change affects our business. Well, given that humans have already brought all the major pests to pretty much every country and certainly every major human activity center, it’s not as much the case as you might think,” says Green Assets.
Is climate change responsible for this apparent arthropod invasion?
The good news is that those who fear encountering stray Brazilian wandering spiders can rest assured.
Most species need more than just a rise in temperature to settle into new and completely different ecosystems. For example, in the docks of Sheerness near London, there was a population of 10,000 yellow scorpions for centuriessince merchant ships brought them from mainland Europe. But the harmless creatures have not spread because the conditions are not right.
Impact of climate change on Europe’s pest population
However, this does not mean that climate change has no impact on Europe’s pest profile.
Termites, which have long been a problem in Mediterranean countries, are also moving into northern Europe as temperatures rise. However, as there are relatively few wooden buildings there, they are unlikely to cause major economic damage.
Aedes Mosquitoes – including the tiger mosquito – are widespread in Italy and are also spreading in France, so countries like Switzerland are unlikely to be spared.
“Europe is already seeing how climate change is creating more favourable conditions for the spread of invasive mosquitoes into previously unaffected areas,” said Andrea Ammon, director of the European Centre for Disease Prevention and Control. told the BBC.
Fortunately, it is not viruses that transmit malaria. anopheleswhose spread to Europe is unlikely, as there are no large standing waters there, which – unlike Aedes– it must multiply.
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The same cannot be said for Asian hornets which, depending on where you live, could soon be coming to a picnic near you. “They move through France quite easily and there are cases of them overwintering in the UK, which means we probably have them now, so make do with it,” says Green.
And then there are the bed bugs. Even before the recent increase, infestations cost the French economy 230 million euros (246 million dollars) annually, according to the health authority. Answer. Operations can cause hotels to default Treatments worth thousands of dollars and loss of income and could trigger hysteria and panic during the Olympic Games in Paris.
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These six-legged vampires have always been there, but they prefer warmer weather.
“If the temperature in your house is 25 to 26 degrees Celsius, it only takes five days for the bed bug eggs to hatch. Under normal conditions, when the temperature is around 20 degrees Celsius, it takes 10 days,” said entomologist and co-founder of the National Institute for the Study and Control of Bed Bugs, Jean-Michel Bérenger. Wired at the height of the panic last year
How Europe’s pests are changing beyond climate change
Whether rising temperatures contribute to this or not, we are more likely to see pests in the future that are best adapted to humans and their behavior – and our behavior contributes to their spread.
In rural areas this is usually done through monoculture farming, but sometimes a preference for importing non-native plants is sufficient.
The oak processionary moth – a species endemic to southern Europe that damages forests and sheds hairs that can irritate the skin, eyes and respiratory tract –put a foot in the door in the UK in the 2000s, when an oak tree was shipped from Europe. Ironically, this happened very close to the Royal Botanical Gardens in Kew, where the authorities monitor such things.
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However, it is the urban pests that you are more likely to notice.
Rats, mice, cockroaches and other animals all share characteristics that make them ideal for living near humans, whether we want them to or not. They are small, can crawl through tight spaces and are generally dark and nocturnal, making them difficult to spot. Crucially, they are also omnivorous.
“They are extremely flexible, so they won’t care about one or two degrees. [change in temperature]. They already live in air-conditioned buildings,” says Rentokil’s Green. “Some moths in warehouses today hardly fly at all. They don’t have to. They just live in a world full of food that is being transported back and forth by people. It’s a hellish life.”
Sometimes it is a well-intentioned or necessary change in human behavior that contributes to the spread of urban pests.
Aside from the media hype, bed bug populations did increased rapidly worldwide in the early 21st century. Australiathe increase was between 500% and 4,500%; in New York City, complaints about bed bugs to the City Council rose from 537 in 2004 to 10,985 in 2009, although since dropped.
Entomologists attribute the revival of the DDT era to its end – the infamous insecticide dramatically reduced the number of global insect pests in the mid- to late 20th century before serious environmental and health concerns ended its use and species began to develop resistance. Essentially, we are returning to historical norms from a time of unusually low insect activity.
Don’t expect that to change. Although the pest control industry is increasingly using more sophisticated surveillance strategies and “physical” interventions, such as steam cleaning rooms with bed bugs, the move away from chemical control methods means we are losing a once effective weapon against infestations.
Something similar could now happen with rats, at least in Europe, where regulators increasingly cloudy visibility on the use of anticoagulant rodenticides.
While there may be good reasons for this, it is making pest controllers nervous. As one person put it off the record: “There is a whole generation of pest controllers who have been trained to put rat poison in bait boxes. If you take that off the market, what will be left?” Alienswhat should we use, harsh words?”
The future
Humanity has driven many species to extinction, mostly unintentionally, and it continues to do so. However, the species that at least some of us want less of have proven stubbornly resilient. Almost by definition, when we do this, pests thrive.
So what can we expect? In Europe, climate change and human activities are unlikely to result in deadly spiders being bought regularly in supermarkets, nor will mosquito-borne diseases reach tropical proportions.
But they will change the populations of the animals we share our environment with. Get used to Aedes and Asian hornets, and be alert to rats and bed bugs.
But perhaps what will change most is our expectation of pest control. The “spray first, ask questions later” approach is finally history, and eliminating pests when they first appear may end up being remembered as a very 20th century idea.