Around 2,500 new alien species are predicted to arrive in Europe by 2050, according to scientists.

The researchers believe number of non-native species is expected to increase globally by 36% by mid-century, compared to 2005.

In the study published in the journal Global Change Biology, the team from University College London said the rise will be particularly seen in insects, arthropods and birds.

In Europe, where the rate of invasion is predicted to be the highest, new arrivals will increase for all plant and animal groups except mammals, they added.

Non-native or alien species are those that have been moved around the world to places where they do not naturally occur.

Some of these species can become invasive, such as the signal crayfish and grey squirrel in the UK, causing damage to the ecosystems.

They can also wreak havoc on the economy, with alien invasive species costing the UK economy around £1.7 billion every year – £166 million of which is spent on tackling Japanese knotweed.

The researchers say imposing stricter regulations could help reduce the numbers.

Study co-author Tim Blackburn, a professor at University College London’s Centre for Biodiversity & Environment Research, said: “Our study predicts that alien species will continue to be added to ecosystems at high rates through the next few decades, which is concerning as this could contribute to harmful biodiversity change and extinction.

“But we are not helpless bystanders: with a concerted global effort to combat this, it should be possible to slow down or reverse this trend.”

The most recent comprehensive global catalogue of alien species took place in 2005, where more than 35,000 such species were recorded.

For the study, the research team developed a mathematical model to calculate how many more aliens would be expected by 2050.

Based on their findings, Dr Blackburn said, on average, around 1,200 new species are expected to arrive in each of the eight regions – Africa, temperate Asia, tropical Asia, Australia, Europe, North America, South America, and Pacific Islands – by mid century.

The largest increase is expected in Europe, he added, where the number of alien species is expected to rise by 64%.

Parts of Asia, North America, and South America are also predicted to be alien hotspots with the lowest relative increase expected in Australia.

Lead author Dr Hanno Seebens, of the Senckenberg Biodiversity and Climate Research Centre in Germany, said: “We will not be able to entirely prevent the introduction of alien species, as this would mean severe restrictions in international trade.

“However, stricter regulations and their rigorous enforcement could greatly slow the flow of new species.

“The benefits of such measures have been shown in some parts of the world.

“Regulations are still comparatively lax in Europe, and so there is great potential here for new measures to curtail the arrival of new aliens.”