The BA Science News Digest - 17 October 2008
In the science news this week: tackling the UK’s most invasive plant, how pigs could help boost human immune systems and the Antarctic mountain mission seeking the world’s oldest ice. Plus, hope for our endangered native red squirrels…
Scientists have uncovered a new genetic link to male pattern baldness, a condition where hair is lost from the temples and crown. Around 30 per cent of men are thought to be affected by it by the time they turn 45.
Two gene regions were identified by screening the DNA of more than 1,000 bald men, reported the Times. Around 14 per cent of men are thought to carry both gene variants, and they have a 70 per cent chance of losing their hair early – seven times greater than men who have neither version.
One of the two implicated DNA regions was already known and is located on the X chromosome, meaning it is only passed from mother to son. The newly identified second region, involving one or more genes on chromosome 20, is the first clue to how baldness can be passed from father to son.
In addition to furthering our understanding of how baldness runs in families, the research published in the journal Nature Genetics could help identify men at risk of premature hair loss. Professor Tim Spector, of King’s College London, who led the study, hopes this could allow men to benefit from early treatment.
‘Baldness is a major cause of depression, social shyness and stigma for some people, particularly those who go bald in their early years,’ he told the Guardian. ‘Hopefully this will encourage pharmaceutical companies to target these people with preventative gels and creams, which may be more effective than treatments used many years after the hair follicles have already died.’
--------------------
Piglets could help ‘turbo-charge’ cancer patients’ immune systems, according to new research detailed in New Scientist.
The prospect of being able to treat cancer patients with boosted numbers of their own immune cells is an exciting one, but the process of cloning T-cells is extremely expensive and difficult for the majority of patients. Now, however, scientists have successfully shown that it’s possible to ‘grow a human immune system’ inside pigs.
Researchers from the University of Michigan extracted stem cells from human umbilical cord blood and bone marrow and then injected them into developing pig foetuses. Since the foetuses didn’t have a mature immune system, they accepted the tissue as their own.
When the piglets were born, the team were able to extract a diverse range of human T-cells, which were then tested for safety and efficacy. When the cells were mixed with ordinary cells from the human donor they didn’t mount an attack – demonstrating that in principle it would be safe to implant them back into the donor. Since the cells did attack cells from other people, they were functional.
(Read more in the Times)
--------------------
There is evidence that an increasing number of people are using mind-enhancing drugs to boost alertness and maximise their learning power, according to a neuropsychologist from the University of Cambridge ahead of a debate on the drugs.
BBC News reported that, according to a poll of 1,400 people by the journal Nature, one in five had taken Ritalin, Provigil or beta-blockers for non-medical reasons. Of those users, 62 per cent had taken the stimulant Ritalin (usually prescribed to treat hyperactive children) and 44 per cent had taken Provigil (designed to alleviate daytime tiredness in people suffering from the sleep disorder narcolepsy).
According to Professor Barbara Sahakian, data suggests use of the drugs outside their clinical setting is becoming more popular and is rising among increasingly younger people. She believes safety trials are urgently needed as ‘we do not really have long-term efficacy and safety data in healthy people’.
Bioethics Professor John Harris, from the University of Manchester, said people should be able to make up their own minds. ‘If these cognitive enhancing drugs make our lives better and make us better able to concentrate and better able to perform, this would surely be a good thing,’ he said.
--------------------
Scientists have shown for the first time in monkeys that signals from a single brain cell can be used to control a paralysed limb, offering future hope for treatments for people who have lost the use of their limbs due to strokes or spinal cord injuries.
Researchers from the University of Washington in Seattle implanted ultra thin electrodes into macaque monkeys that had been trained to play a game that involved rotating their wrists left and right, reported the Guardian. The electrodes picked up signals that made them tense different muscles. A substance was then injected to temporarily paralyse the monkeys’ arms, and brain signals amplified and sent via a wire directly to muscles in the monkeys’ wrists.
Initially the monkeys were unable to play the game, but they soon learned to control their wrist movements using the brain implant – even when it was connected to nerves not involved in wrist control.
Study leader Eberhard Fetz explained: ‘The monkey was experimenting with different types of movement and different types of cognitive activity to drive those neurons and when he found something worked, he quickly repeated it and adopted the strategy.’
Researchers now need to overcome a number of hurdles before the system could be safely used in humans, such as removing the need for wires, which increase the risk of infection.
--------------------
The next story is a lesson in the value of keeping good records of your experiments and labelling samples clearly: new data has come to light from the groundbreaking 1950s experiments in which the building blocks of life (amino acids) were created in the lab using a mixture of gases and electric sparks.
The experiments, which made an overnight celebrity out of 22-year-old PhD student Stanley Miller, ‘remained iconic in their attempt at simulating pre-biotic chemistry, but became irrelevant in detail’ reports the BBC, because ‘it became clear that the Earth’s early atmosphere was nothing like the “reducing” mixture simulated in his apparatus’.
Miller also conducted further experiments in which he injected hot steam into the gas mixture. These intrigued his former student Jeffrey Bada, as the conditions were like those you might find in an erupting volcano. However, Miller published only sketchy details.
When Professor Miller died in May last year, Professor Bada inherited his materials: ‘We started going through some of the stuff that was piled up in the corner, and here were several little cardboard boxes, taped shut and all dusty, carefully labelled with all of these little vials with dried material from his experiments.
‘We started sorting through these, and lo and behold, we found a whole collection, almost a complete collection, of the extract samples from the volcanic experiments. And so we just went at it, using the state-of-the-art techniques we have today and analysed these samples. We found not only did these make more of certain amino acids than in the classic experiment, but they made a greater diversity of amino acids.’
The latest work has been reported in the journal Science. Almost all volcanic eruptions are today accompanied by violent electric storms and Professor Bada thinks the same could have been true before life began on Earth. He suggests that each erupting volcano could have served as a little, local prebiotic factory, and that the materials produced could have been washed down the sides of volcanoes into water, where they might have kick-started evolution.
--------------------
An international team of scientists, engineers, pilots and support staff from the UK, US, Germany, Australia, China and Japan will be working together to try to solve the mystery of the massive mountain range in the middle of Antarctica.
‘This region is a complete enigma,’ said Dr Fausto Ferraccioli from the British Antarctic Survey. ‘It’s in the middle of the continent. Most mountain ranges are on the edges of continents, and we really can’t understand what these mountains are doing in the centre.’
One of the leading researchers from the US, Dr Robin Bell, added: ‘There are two easy ways to make mountains. One is colliding continents, but after they collide they tend to erode; and the last collision was 500-million-plus years ago. They shouldn’t be there. The other way is a hotspot, [with volcanoes punching through the crust] like in Hawaii; but there’s no good evidence for underneath the ice sheet being that hot.
‘I like to say it’s rather like being an archaeologist and opening up a tomb in a pyramid and finding an astronaut sitting inside. It shouldn’t be there.’
The mountains lie under 4km of ice in some places, and the expedition will ‘map everything from the detailed ripples on the surface of the ice sheet down to the temperature structure hundreds of kilometres in the Earth,’ said Dr Bell.
The project also aims to find locations in which to drill for ancient ices. It is thought that it may be possible to drill down to ices that are more than a million years old – at least 200,000 years older than any that scientists are currently studying – providing important information about past environmental conditions from the trapped bubbles of air.
(Read more at BBC News)
-----------------
The last chimp ‘stronghold’ which contains more than half of the world’s chimp population – the Côte d’Ivoire – has seen a 90 per cent fall in numbers since the last count, according to a new survey. Numbers have dwindled to little more than 1,000 individuals which exist in highly fragmented populations – with only one viable population remaining in Taï National Park, say scientists.
One of the researchers who conducted the study, Christophe Boesch, of the Max Planck Institute for Evolutionary Anthropology, blames a rise in the human population.
‘The human population in Côte d’Ivoire has increased nearly 50 per cent over the last 18 years,’ he said. ‘Since most threats to chimpanzee populations are derived from human activities such as hunting and deforestation, this has contributed to the dramatic decline in chimpanzee populations. The situation has deteriorated even more with the start of the civil war in 2002, since all surveillance ceased in the protected areas.’
(The Telegraph)
--------------------
Meanwhile, new evidence suggests Bonobos – another endangered chimpanzee species found only in the Democratic Republic of Congo – don’t fully deserve their ‘make love not war’ hippy-like reputation (as the Telegraph put it).
Their closely related common chimpanzee relative is known to be violently aggressive towards chimps from other colonies and in the way it hunts monkeys for food. Bonobos, on the other hand, were thought to live largely peaceful lives and eat only the meat of small forest antelopes, squirrels and rodents. Until now, that is: new observations, reported in the journal Current Biology, revealed bonobo hunting parties in which monkeys were captured, killed and eaten.
Females actively participated in the pursuit – something never seen in common chimpanzees. The discovery challenges the widely held belief that male dominance and aggression is causally linked to hunting behaviour.
--------------------
Other news in brief:
Some EU countries are arguing that the current financial crisis means they can no longer afford the huge costs required to meet ambitious targets to cut greenhouse gas emissions.
José Manuel Barroso, the European Commision chief, commented: ‘The targets have been agreed and we have presented them all over the world. There will be a real problem of credibility for Europe. Saving the planet is not an after-dinner drink, a digestif that you take or leave. Climate change does not disappear because of the financial crisis.’
(The Guardian)
--------------------
Inspections of the Large Hadron Collider have revealed that a faulty electrical connection was to blame for the helium leak that meant it had to be shut down until spring, delaying the first particle collisions for several months.
(The Times)
--------------------
The discovery of two nine thousand-year-old tuberculosis victims has challenged the traditionally held belief that humans caught the disease from cattle after their domestication, as this took place around three thousand years later.
The ancient remains of the mother and child were discovered in a submerged Neolithic village of the coast of Haifa, in Israel. DNA examination ‘confirmed the latest theory that bovine TB evolved later than human TB’, reported the Guardian.
--------------------
Arachnophobes look away now…
According to experts, exotic species of spider that have hitched a ride into the UK on food and plant imports are now able to survive and spread, thanks to our increasingly mild climate.
Stuart Hine, who runs the Natural History Museum’s Insect Identification Service, said hitchhiking spiders and insects are not a new phenomenon but their increased survival is. ‘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.’
Some invasive species that once only existed within small pockets in the UK have recently started spreading. These include the false widow spider Steatoda nobilis that is thought to have entered the UK from the Mediterranean in the 1800s. Over the past 15 years, it has spread from a small area within Devon all along the South Coast. ‘It has a nasty bite – and some people can have a bad reaction to it,’ said Mr Hines.
The tube web spider is another non-native biting species that has been spreading northwards from the South Coast. According to Mr Hines it’s aggressive for a spider and whereas most spiders will back away as you approach it, ‘this one will jump at you and bite’. He told BBC News he thinks it is only a matter of time before black widow spiders also make the UK their home.
Conservation group Buglife called for stronger import rules to protect ‘our goods, livelihoods, health and biodiversity’ from alien pests. A spokesperson for the Department for Environment, Food and Rural Affairs (Defra) said that there is already a new strategy in place to ‘tackle the threat to the UK’s native biodiversity from unwanted pest species which have “hitchhiked” into the UK on plants.’
--------------------
BBC News was running features on the UK’s alien invaders all week. Read their reports to find out more about some of the other non-native species that could start causing problems to our native wildlife.
--------------------
In a related story, a tiny sap-sucking insect from Japan could purposely be introduced into British countryside next summer in an attempt to bring our most invasive plant – Japanese knotweed – under control.
Japanese knotweed was introduced as an ornamental plant in the Victorian era. Too late, it was found to be extremely invasive – it has colonised almost all of Britain and even tiny fragments can grow through tarmac and concrete. It is one of only a few plants for which cultivation and movement is banned.
The cost of using chemicals and other conventional approaches to destroy the plant would be at least £1.5 billion. So, in an effort to find another (cheaper) solution, scientists from the Centre for Agricultural Bioscience International (Cabi) have looked to see what controls the plant in its native Japan.
They assessed 186 insect species and 40 fungi for their potential to damage the knotweed, and also tested them on 79 different plants to check that the damage was selective. The 2mm plant louse, Aphalara itadori, and one leafspot fungus were found to be effective and have the most potential for controlling the knotweed, although they are not expected to eradicate it.
A public consultation is expected to be launched shortly into the acceptability of introducing the plant louse. Defra must also decide whether it is safe to be released under licence, as the potential to cause damage to the environment rather than protect it as intended must be fully considered. If the release goes ahead, it would be the first biocontrol deliberately imported into Britain, reported the Times.
--------------------
And finally…
Some hope for the UK’s threatened red squirrels, reports the Independent: they appear to have developed an apparent immunity to the squirrel pox virus – a deadly virus being spread by grey squirrels. The discovery may mean it could be possible to develop a vaccine.
Experts fear the native reds could face extinction in England and Wales within 25 years. They have faced rapid decline since the introduction of their grey cousins from America in 1876, as their rivals encroach on their territories and spread the virus which greys appear to carry but not be affected by. Only about 140,000 red squirrels remain in Britain (about 75 per cent of these in Scotland), compared to 2.5 million grey squirrels.
However, while it was previously thought that the virus was 100 per cent lethal to red squirrels, a survey of more than 500 red squirrel corpses has identified eight that had been exposed to the virus but died of other causes. Another captive red squirrel has also been found to survive exposure to the virus.
Scientists who conducted the study believe the presence of antibodies against the virus is strong circumstantial evidence that some wild red squirrels have developed a natural immunity. ‘We have found either that they can be exposed to the disease and still manage to survive, or that they have been exposed to the virus and have not developed the disease,’ said Tony Sainsbury, of the Zoological Society of London, who led the investigation.
Scientists have uncovered a new genetic link to male pattern baldness, a condition where hair is lost from the temples and crown. Around 30 per cent of men are thought to be affected by it by the time they turn 45.
Two gene regions were identified by screening the DNA of more than 1,000 bald men, reported the Times. Around 14 per cent of men are thought to carry both gene variants, and they have a 70 per cent chance of losing their hair early – seven times greater than men who have neither version.
One of the two implicated DNA regions was already known and is located on the X chromosome, meaning it is only passed from mother to son. The newly identified second region, involving one or more genes on chromosome 20, is the first clue to how baldness can be passed from father to son.
In addition to furthering our understanding of how baldness runs in families, the research published in the journal Nature Genetics could help identify men at risk of premature hair loss. Professor Tim Spector, of King’s College London, who led the study, hopes this could allow men to benefit from early treatment.
‘Baldness is a major cause of depression, social shyness and stigma for some people, particularly those who go bald in their early years,’ he told the Guardian. ‘Hopefully this will encourage pharmaceutical companies to target these people with preventative gels and creams, which may be more effective than treatments used many years after the hair follicles have already died.’
--------------------
Piglets could help ‘turbo-charge’ cancer patients’ immune systems, according to new research detailed in New Scientist.
The prospect of being able to treat cancer patients with boosted numbers of their own immune cells is an exciting one, but the process of cloning T-cells is extremely expensive and difficult for the majority of patients. Now, however, scientists have successfully shown that it’s possible to ‘grow a human immune system’ inside pigs.
Researchers from the University of Michigan extracted stem cells from human umbilical cord blood and bone marrow and then injected them into developing pig foetuses. Since the foetuses didn’t have a mature immune system, they accepted the tissue as their own.
When the piglets were born, the team were able to extract a diverse range of human T-cells, which were then tested for safety and efficacy. When the cells were mixed with ordinary cells from the human donor they didn’t mount an attack – demonstrating that in principle it would be safe to implant them back into the donor. Since the cells did attack cells from other people, they were functional.
(Read more in the Times)
--------------------
There is evidence that an increasing number of people are using mind-enhancing drugs to boost alertness and maximise their learning power, according to a neuropsychologist from the University of Cambridge ahead of a debate on the drugs.
BBC News reported that, according to a poll of 1,400 people by the journal Nature, one in five had taken Ritalin, Provigil or beta-blockers for non-medical reasons. Of those users, 62 per cent had taken the stimulant Ritalin (usually prescribed to treat hyperactive children) and 44 per cent had taken Provigil (designed to alleviate daytime tiredness in people suffering from the sleep disorder narcolepsy).
According to Professor Barbara Sahakian, data suggests use of the drugs outside their clinical setting is becoming more popular and is rising among increasingly younger people. She believes safety trials are urgently needed as ‘we do not really have long-term efficacy and safety data in healthy people’.
Bioethics Professor John Harris, from the University of Manchester, said people should be able to make up their own minds. ‘If these cognitive enhancing drugs make our lives better and make us better able to concentrate and better able to perform, this would surely be a good thing,’ he said.
--------------------
Scientists have shown for the first time in monkeys that signals from a single brain cell can be used to control a paralysed limb, offering future hope for treatments for people who have lost the use of their limbs due to strokes or spinal cord injuries.
Researchers from the University of Washington in Seattle implanted ultra thin electrodes into macaque monkeys that had been trained to play a game that involved rotating their wrists left and right, reported the Guardian. The electrodes picked up signals that made them tense different muscles. A substance was then injected to temporarily paralyse the monkeys’ arms, and brain signals amplified and sent via a wire directly to muscles in the monkeys’ wrists.
Initially the monkeys were unable to play the game, but they soon learned to control their wrist movements using the brain implant – even when it was connected to nerves not involved in wrist control.
Study leader Eberhard Fetz explained: ‘The monkey was experimenting with different types of movement and different types of cognitive activity to drive those neurons and when he found something worked, he quickly repeated it and adopted the strategy.’
Researchers now need to overcome a number of hurdles before the system could be safely used in humans, such as removing the need for wires, which increase the risk of infection.
--------------------
The next story is a lesson in the value of keeping good records of your experiments and labelling samples clearly: new data has come to light from the groundbreaking 1950s experiments in which the building blocks of life (amino acids) were created in the lab using a mixture of gases and electric sparks.
The experiments, which made an overnight celebrity out of 22-year-old PhD student Stanley Miller, ‘remained iconic in their attempt at simulating pre-biotic chemistry, but became irrelevant in detail’ reports the BBC, because ‘it became clear that the Earth’s early atmosphere was nothing like the “reducing” mixture simulated in his apparatus’.
Miller also conducted further experiments in which he injected hot steam into the gas mixture. These intrigued his former student Jeffrey Bada, as the conditions were like those you might find in an erupting volcano. However, Miller published only sketchy details.
When Professor Miller died in May last year, Professor Bada inherited his materials: ‘We started going through some of the stuff that was piled up in the corner, and here were several little cardboard boxes, taped shut and all dusty, carefully labelled with all of these little vials with dried material from his experiments.
‘We started sorting through these, and lo and behold, we found a whole collection, almost a complete collection, of the extract samples from the volcanic experiments. And so we just went at it, using the state-of-the-art techniques we have today and analysed these samples. We found not only did these make more of certain amino acids than in the classic experiment, but they made a greater diversity of amino acids.’
The latest work has been reported in the journal Science. Almost all volcanic eruptions are today accompanied by violent electric storms and Professor Bada thinks the same could have been true before life began on Earth. He suggests that each erupting volcano could have served as a little, local prebiotic factory, and that the materials produced could have been washed down the sides of volcanoes into water, where they might have kick-started evolution.
--------------------
An international team of scientists, engineers, pilots and support staff from the UK, US, Germany, Australia, China and Japan will be working together to try to solve the mystery of the massive mountain range in the middle of Antarctica.
‘This region is a complete enigma,’ said Dr Fausto Ferraccioli from the British Antarctic Survey. ‘It’s in the middle of the continent. Most mountain ranges are on the edges of continents, and we really can’t understand what these mountains are doing in the centre.’
One of the leading researchers from the US, Dr Robin Bell, added: ‘There are two easy ways to make mountains. One is colliding continents, but after they collide they tend to erode; and the last collision was 500-million-plus years ago. They shouldn’t be there. The other way is a hotspot, [with volcanoes punching through the crust] like in Hawaii; but there’s no good evidence for underneath the ice sheet being that hot.
‘I like to say it’s rather like being an archaeologist and opening up a tomb in a pyramid and finding an astronaut sitting inside. It shouldn’t be there.’
The mountains lie under 4km of ice in some places, and the expedition will ‘map everything from the detailed ripples on the surface of the ice sheet down to the temperature structure hundreds of kilometres in the Earth,’ said Dr Bell.
The project also aims to find locations in which to drill for ancient ices. It is thought that it may be possible to drill down to ices that are more than a million years old – at least 200,000 years older than any that scientists are currently studying – providing important information about past environmental conditions from the trapped bubbles of air.
(Read more at BBC News)
-----------------
The last chimp ‘stronghold’ which contains more than half of the world’s chimp population – the Côte d’Ivoire – has seen a 90 per cent fall in numbers since the last count, according to a new survey. Numbers have dwindled to little more than 1,000 individuals which exist in highly fragmented populations – with only one viable population remaining in Taï National Park, say scientists.
One of the researchers who conducted the study, Christophe Boesch, of the Max Planck Institute for Evolutionary Anthropology, blames a rise in the human population.
‘The human population in Côte d’Ivoire has increased nearly 50 per cent over the last 18 years,’ he said. ‘Since most threats to chimpanzee populations are derived from human activities such as hunting and deforestation, this has contributed to the dramatic decline in chimpanzee populations. The situation has deteriorated even more with the start of the civil war in 2002, since all surveillance ceased in the protected areas.’
(The Telegraph)
--------------------
Meanwhile, new evidence suggests Bonobos – another endangered chimpanzee species found only in the Democratic Republic of Congo – don’t fully deserve their ‘make love not war’ hippy-like reputation (as the Telegraph put it).
Their closely related common chimpanzee relative is known to be violently aggressive towards chimps from other colonies and in the way it hunts monkeys for food. Bonobos, on the other hand, were thought to live largely peaceful lives and eat only the meat of small forest antelopes, squirrels and rodents. Until now, that is: new observations, reported in the journal Current Biology, revealed bonobo hunting parties in which monkeys were captured, killed and eaten.
Females actively participated in the pursuit – something never seen in common chimpanzees. The discovery challenges the widely held belief that male dominance and aggression is causally linked to hunting behaviour.
--------------------
Other news in brief:
Some EU countries are arguing that the current financial crisis means they can no longer afford the huge costs required to meet ambitious targets to cut greenhouse gas emissions.
José Manuel Barroso, the European Commision chief, commented: ‘The targets have been agreed and we have presented them all over the world. There will be a real problem of credibility for Europe. Saving the planet is not an after-dinner drink, a digestif that you take or leave. Climate change does not disappear because of the financial crisis.’
(The Guardian)
--------------------
Inspections of the Large Hadron Collider have revealed that a faulty electrical connection was to blame for the helium leak that meant it had to be shut down until spring, delaying the first particle collisions for several months.
(The Times)
--------------------
The discovery of two nine thousand-year-old tuberculosis victims has challenged the traditionally held belief that humans caught the disease from cattle after their domestication, as this took place around three thousand years later.
The ancient remains of the mother and child were discovered in a submerged Neolithic village of the coast of Haifa, in Israel. DNA examination ‘confirmed the latest theory that bovine TB evolved later than human TB’, reported the Guardian.
--------------------
Arachnophobes look away now…
According to experts, exotic species of spider that have hitched a ride into the UK on food and plant imports are now able to survive and spread, thanks to our increasingly mild climate.
Stuart Hine, who runs the Natural History Museum’s Insect Identification Service, said hitchhiking spiders and insects are not a new phenomenon but their increased survival is. ‘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.’
Some invasive species that once only existed within small pockets in the UK have recently started spreading. These include the false widow spider Steatoda nobilis that is thought to have entered the UK from the Mediterranean in the 1800s. Over the past 15 years, it has spread from a small area within Devon all along the South Coast. ‘It has a nasty bite – and some people can have a bad reaction to it,’ said Mr Hines.
The tube web spider is another non-native biting species that has been spreading northwards from the South Coast. According to Mr Hines it’s aggressive for a spider and whereas most spiders will back away as you approach it, ‘this one will jump at you and bite’. He told BBC News he thinks it is only a matter of time before black widow spiders also make the UK their home.
Conservation group Buglife called for stronger import rules to protect ‘our goods, livelihoods, health and biodiversity’ from alien pests. A spokesperson for the Department for Environment, Food and Rural Affairs (Defra) said that there is already a new strategy in place to ‘tackle the threat to the UK’s native biodiversity from unwanted pest species which have “hitchhiked” into the UK on plants.’
--------------------
BBC News was running features on the UK’s alien invaders all week. Read their reports to find out more about some of the other non-native species that could start causing problems to our native wildlife.
--------------------
In a related story, a tiny sap-sucking insect from Japan could purposely be introduced into British countryside next summer in an attempt to bring our most invasive plant – Japanese knotweed – under control.
Japanese knotweed was introduced as an ornamental plant in the Victorian era. Too late, it was found to be extremely invasive – it has colonised almost all of Britain and even tiny fragments can grow through tarmac and concrete. It is one of only a few plants for which cultivation and movement is banned.
The cost of using chemicals and other conventional approaches to destroy the plant would be at least £1.5 billion. So, in an effort to find another (cheaper) solution, scientists from the Centre for Agricultural Bioscience International (Cabi) have looked to see what controls the plant in its native Japan.
They assessed 186 insect species and 40 fungi for their potential to damage the knotweed, and also tested them on 79 different plants to check that the damage was selective. The 2mm plant louse, Aphalara itadori, and one leafspot fungus were found to be effective and have the most potential for controlling the knotweed, although they are not expected to eradicate it.
A public consultation is expected to be launched shortly into the acceptability of introducing the plant louse. Defra must also decide whether it is safe to be released under licence, as the potential to cause damage to the environment rather than protect it as intended must be fully considered. If the release goes ahead, it would be the first biocontrol deliberately imported into Britain, reported the Times.
--------------------
And finally…
Some hope for the UK’s threatened red squirrels, reports the Independent: they appear to have developed an apparent immunity to the squirrel pox virus – a deadly virus being spread by grey squirrels. The discovery may mean it could be possible to develop a vaccine.
Experts fear the native reds could face extinction in England and Wales within 25 years. They have faced rapid decline since the introduction of their grey cousins from America in 1876, as their rivals encroach on their territories and spread the virus which greys appear to carry but not be affected by. Only about 140,000 red squirrels remain in Britain (about 75 per cent of these in Scotland), compared to 2.5 million grey squirrels.
However, while it was previously thought that the virus was 100 per cent lethal to red squirrels, a survey of more than 500 red squirrel corpses has identified eight that had been exposed to the virus but died of other causes. Another captive red squirrel has also been found to survive exposure to the virus.
Scientists who conducted the study believe the presence of antibodies against the virus is strong circumstantial evidence that some wild red squirrels have developed a natural immunity. ‘We have found either that they can be exposed to the disease and still manage to survive, or that they have been exposed to the virus and have not developed the disease,’ said Tony Sainsbury, of the Zoological Society of London, who led the investigation.
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