Alien Creepy Crawlies Arrive in UK
Exotic species of spiders are making their homes in the UK, scientists
say.
Researchers believe arachnids arriving in imports of food and plants
are now able to survive and spread thanks to the UK's increasingly
mild climate.
The new inhabitants include a species of false widow spider and some
believe the deadly black widow could be next to invade.
Conservation group Buglife wants import rules to be strengthened to
stem the tide of alien species invasion.
Matt Shardlow, director of Buglife, told BBC News: "Other countries in
the world take great care about what biological material they allow
in, because it can contain pests that can damage our goods, our
livelihoods, our health and our biodiversity.
Our increasingly warm climate is starting to suit many more spiders
Stuart Hine, Natural History Museum
See other insects invading the UK
"Currently in the UK, we have a laissez-faire attitude - there is an
open licence for people to bring in dangerous pests."
But a spokesperson for the Department for Environment, Food and Rural
Affairs (Defra) said that a new strategy was in place to "tackle the
threat to the UK's native biodiversity from unwanted pest species
which have 'hitchhiked' into the UK on plants".
All this week, BBC News will be taking a closer look at some of the
alien invaders that are in the UK.
Aggressive arachnid
John Partridge from the British Arachnological Society said his
organisation had had an increase in the number of enquiries about
"strange spiders".
He added: "We are certainly getting more spiders coming into the UK -
and it seems that more are spreading around the country once they are in."
False widow Steatoda paykulliana is a new resident in the UK
One new inhabitant is Steatoda paykulliana, a false widow spider that
is native to Southern Europe, West Asia and North Africa.
It is about 0.7-1.5cm (0.3-0.6in) in size and can bite.
While this spider had been spotted in the UK in the past, it was
thought that no colonies had established.
But Stuart Hine, who runs the Insect Identification Service at the
Natural History Museum, said this was no longer the case.
He said: "Now we have found it in Plymouth. And it looks as if it is
here to stay."
The arrival of exotic spiders and insects that had hitched a ride on
various imports was not a new phenomenon, said Mr Hine.
"If there was a warm period they would be able to survive, but a cold
snap would kill them off," he explained.
"But now, our increasingly warm climate is starting to suit many more
spiders - and once they come in, they are able to stay put."
This has also meant that some invasive species that once only existed
within a few small pockets in the UK have been able to spread.
Steatoda nobilis is one such spider.
UK's 'most venomous' spider
This false widow is thought to have first arrived in the UK from the
Mediterranean in the late 1800s.
For many decades it remained in a small area within Devon, but about
15 years ago it began to spread and it can now be spotted all along
the South Coast.
Mr Hine said: "It has a nasty bite - and some people can have a bad
reaction to it."
The tube web spider (Segestria florentina), another non-native biting
spider, has also been on the move, spreading from the South Coast much
further north.
It is a large spider, measuring between 1.5cm and 2.2cm (0.6-0.9in),
with green iridescence on its jaws.
Mr Hine said: "In spider terms, it has to be said that this is an
aggressive spider.
"If you approach it, it raises its legs and bares its fangs.
"Most spiders will back away - this one will jump at you and bite."
Mr Hine believes that the black widow spider could be next on the list
for the UK.
He said: "There is no great reason that they wouldn't survive here now
- winters are now mild enough.
"It really is only a matter of time."
A balancing act
While experts stress that not all new species have a negative impact,
they do warn that trade is a key factor in the number of new species
that enter the country.
Defra is responsible for checking the products that enter the UK.
Black widow
A spokesperson told the BBC: "The government and its agencies work
with businesses, overseas authorities and the general public to
minimise the risk of exotic animal and plant pests and diseases from
entering the country and threatening public health, livestock,
agriculture, horticulture and the environment.
"Disease can enter the country in many ways; that's why Defra
undertakes international disease monitoring, while there are also
strict controls on the movement of livestock and animals."
But Mr Shardlow from Buglife said: "We cannot just view moving
biological material around like other trade products.
"You have to have a bit of environmental awareness, and I think we
should be looking to import and export less biological material."
BBC: October 2008
