Bedbugs and other pests are back thanks to climate change

Paris is full of bedbugs. Viral videos have shown them on social media and headlines have made them global news. The insects have been spotted in movie theatres, train carriages and on the metro, a nightmare for a city preparing to host the Olympic Games soon. The French media explain that greater summer holiday travel has created a favourable breeding ground for these animals, which have reached levels not seen for a long time.

To pest experts, however, what is happening in France is surprising because of its volume, but less so because of its context. That is, even if we don't usually have cause to think of them, bedbugs are there and that they are there says a lot about the present of pests and the effects of climate change.

Bedbugs had disappeared from Europe and the United States by the 1950s. The use of DDT - now banned - had wiped out the bedbug population. "It was very bad for bedbugs, but very harmful for people," says Jacinto Diaz, spokesman for Rentokil.

Since the late 1990s and early 2000s, bedbugs have been making a comeback in both Europe and the United States. The DDT ban explains this new context, Díaz points out, but it is not the only reason. The processes of globalisation - both global trade patterns and increased travel - and the loss of the habit of inspecting for them - something our grandmothers did almost by default - have led to the return of these insects. So has climate change.

In fact, France is now in the news, but bedbugs have been living in Spain - again - for some time now. It is a problem that the Spanish hotel and catering industry is very aware of and for which they have clear protocols for action, which help them to have it "under control", says Díaz.

In addition, bedbugs have become increasingly resistant to the products that have been used against them. Jorge Galván, the general director of the national association of environmental health companies, ANECPLA, explains: "Resistance is a random genetic mutation." That is, by chance, specimens appear that are not harmed by the pest control system used against them. As their companions - those that are - have died, they are the ones that reproduce. Their genetic trait is thus shared with the following generations.

The effects of the climate emergency are transversal and have an impact on many areas of daily life. The insects that live in our homes, our cities or our means of transport are no strangers to this reality. Bedbugs are one of them. "Why the upturn? Climate change has had a lot to do with it," explains Galván.

"We have more and more insects," says the specialist, who also adds a somewhat paradoxical element to this situation. "We are also having a loss of biodiversity among insects," he says. This is important and tragic, because insects play an important role in nature. They are a part of its balance and what helps it to remain resilient and ultimately alive. We need to be able to reduce at-risk populations, but also helping and maintaining the ecosystem balance. "It is very important that when treatments are done that they go to the target organism," says Galán, who insists that this is why professionals should be used. If an Asian hornet trap catches 10 butterflies in passing, for example, it is a problem.

Population growth also affects many species. Díaz illustrates this with the increase in cockroaches and mosquitoes, "with all the risks that entails". Mosquitoes no longer bite only in summer, a perfect example of what global warming means for them. Experts point out that the insects have become deseasonalised, because their breeding windows have become longer. In addition, their metabolism is speeding up. It's not just that they have more time to lay eggs, they also lay them more often.

In addition, the tropicalisation of the European climate makes the region increasingly attractive to invasive species. Insects such as Asian hornets and tiger mosquitoes are arriving. A few years ago few people would have imagined that the tiger mosquito would arrive in Galicia, says Galán, with a climate very different from that of the tropical areas from which it originates. However, high temperatures due to the climate emergency - and the region's traditional high humidity - have made it an attractive destination. And the tiger mosquitoes of the Rías Baixas are a sample of what is happening in many other areas of Spain.

The future may bring other invasive species and new risks. Díaz talks about the potential threat to Mediterranean coastal areas from the fire ant, which has already been discovered in Sicily and not only bites but also destroys crops. "It all depends on the evolution of the climate," says Galán. If temperatures continue to rise, Europe will no longer become a 'holiday' destination but a life-supporting one for these invasive insect species.

Beyond the nuisance and discomfort, such as longer periods of mosquito bites, the underlying issue is more serious. It is a disruption of the ecosystem. Moreover, it is a public health problem, specialists repeat, as these insects can become vectors for diseases. It is also one that can have a direct economic cost. Asian hornets are already damaging honey harvests or the grape harvests of some designations of origin.

Can these troublesome insects be eliminated at a stroke? Exterminating them is impossible, but not keeping them under control," says Díaz. For pest control specialists, prevention is crucial.

"We must carry out treatments so that we don't have to get used to" this increase in pests, says Galán, who also insists that prevention is more effective, cheaper and more ecological. "Environmental health has evolved," he points out.

Society may still reduce everything to spraying, but in reality, he promises, that is what is done less. It is a more holistic process that takes into account the ecosystem - there are those insects that are so necessary - and sometimes uses substances that are already in nature itself, he explains.