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Honeybee trade is hotbed for carrying disease into wild
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Honeybee trade is hotbed for disease HONEYBEES have been busy – spreading diseases to insects that pollinate crops. It seems imported honeybees are an important reservoir for viruses that kill wild pollinators, which could lead to a meltdown in the planet’s pollination services. World trade in honeybee colonies contributes to honey production and also plays a vital role in agriculture – in some cases there would be no crop without the pollinators. Honeybee colonies in Europe and North America have suffered recent mysterious declines. But now it seems the colonies could be just as much of a threat to wild pollinators such as bumblebees and the many species of “solitary” bees. Matthias Fürst of Royal Holloway, University of London tracked the geographical prevalence in the UK of a nonnative parasite called deformed wing virus (DWV) that is often found in both honeybees and bumblebees. The virus is spread by a mite and typically kills bees
Melty magma hints at coming big eruptions BEFORE volcanoes erupt, they must “defrost”. The magma beneath some of the most dangerous volcanoes may be relatively cool and solid for most of the time. That means evidence that magma is melting could be a sign of an imminent eruption. Deep beneath each volcano is a magma chamber filled with bubbling, molten rock. Or so the thinking goes. Magma chambers sit in Earth’s crust, 16 | NewScientist | 22 February 2014
Alex wild
Fred Pearce
wild (Nature, DOI: 10.1038/ nature12977). “This is a previously unrecognised threat,” says Fürst. While his study looked mainly at how diseases move from honeybees to bumblebees, he warned that the problem “may well play a particularly significant role for already rare and vulnerable pollinator species”. The UK alone is home to around 250 different species of wild solitary bees.
Previous studies in the US have found that honeybees carry a range of viruses, including DWV, Israeli acute paralysis virus, black queen cell virus and sacbrood virus, all of which may be passed on to other pollinators. within 48 hours. The pattern of Disease spread by honeybees spread showed that imported is one more in a growing list of honeybees are the major source of threats to wild pollinators, says infection for the wild pollinators, Matt Shardlow, head of UK NGO and that emerging diseases Buglife. “Pollinators are suffering spread by those colonies could be declines as a result of several a major cause of mortality in the linked factors including habitat loss, pesticides and disease.” But, he says, “this study adds to a developing picture that diseases are a major risk to wild pollinators, and strongly suggests that imported honeybees are the main reservoir for diseases”. Trade in honeybees is controlled by the World Organisation for Animal Health, which has rules to promote free trade while restricting the spread of diseases. But Shardlow says governments must introduce strict hygiene regulations to protect wild pollinators, worth an estimated £500 million a year to the UK economy alone. Fürst says there is no immediate threat to individual crops, since most are pollinated by a variety of insects. “But to keep it that way we need to protect our bees and keep populations healthy and –Worry about the cargo you can’t see– diverse.” n
which is relatively cold – between about 200 °C and 400 °C – so it isn’t clear if they are really hot or not. To find out, Kari Cooper of the University of California, Davis, studied solidified lavas from Mount Hood, a potentially active volcano in Oregon that last erupted 220 years ago. With Adam Kent of Oregon State University in Corvallis, she isolated crystals from the lava. They were at least 21,000 years old, based on the radioactive decay of uranium, a “clock” that began ticking when they formed. There was far more strontium in the crystals’ cores than near their margins. That is odd, because at 750 ºC, the
temperature at which lava begins to melt, strontium would diffuse throughout crystals within a few thousand years. As it hadn’t done so, the crystals can have spent no more than 2800 years above 750 °C, and maybe just 140 years (Nature, doi.org/rhk). So what are the implications of the rock being solid? Magma must be mostly liquid for a volcano to erupt, says Cooper. “This process of ‘defrosting’ a magma body could
“The magma body could defrost before we get any other evidence that an eruption is imminent”
happen before we get any other evidence that an eruption is imminent.” However, a 2013 study suggested that magma chambers under some volcanoes remain molten for long periods, rather than melting just before they erupt (Geology, doi.org/ rgf). That means looking for melting would only help predict some eruptions, but they are often big ones. “Defrosting applies in general to crystal-rich eruptions,” says Christian Huber of the Georgia Institute of Technology in Atlanta. That includes the 1991 Mount Pinatubo eruption in the Philippines, one of the largest of the 20th century. Colin Barras n
Honeybee trade is hotbed for disease HONEYBEES have been busy – spreading diseases to insects that pollinate crops. It seems imported honeybees are an important reservoir for viruses that kill wild pollinators, which could lead to a meltdown in the planet’s pollination services. World trade in honeybee colonies contributes to honey production and also plays a vital role in agriculture – in some cases there would be no crop without the pollinators. Honeybee colonies in Europe and North America have suffered recent mysterious declines. But now it seems the colonies could be just as much of a threat to wild pollinators such as bumblebees and the many species of “solitary” bees. Matthias Fürst of Royal Holloway, University of London tracked the geographical prevalence in the UK of a nonnative parasite called deformed wing virus (DWV) that is often found in both honeybees and bumblebees. The virus is spread by a mite and typically kills bees
Melty magma hints at coming big eruptions BEFORE volcanoes erupt, they must “defrost”. The magma beneath some of the most dangerous volcanoes may be relatively cool and solid for most of the time. That means evidence that magma is melting could be a sign of an imminent eruption. Deep beneath each volcano is a magma chamber filled with bubbling, molten rock. Or so the thinking goes. Magma chambers sit in Earth’s crust, 16 | NewScientist | 22 February 2014
Alex wild
Fred Pearce
wild (Nature, DOI: 10.1038/ nature12977). “This is a previously unrecognised threat,” says Fürst. While his study looked mainly at how diseases move from honeybees to bumblebees, he warned that the problem “may well play a particularly significant role for already rare and vulnerable pollinator species”. The UK alone is home to around 250 different species of wild solitary bees.
Previous studies in the US have found that honeybees carry a range of viruses, including DWV, Israeli acute paralysis virus, black queen cell virus and sacbrood virus, all of which may be passed on to other pollinators. within 48 hours. The pattern of Disease spread by honeybees spread showed that imported is one more in a growing list of honeybees are the major source of threats to wild pollinators, says infection for the wild pollinators, Matt Shardlow, head of UK NGO and that emerging diseases Buglife. “Pollinators are suffering spread by those colonies could be declines as a result of several a major cause of mortality in the linked factors including habitat loss, pesticides and disease.” But, he says, “this study adds to a developing picture that diseases are a major risk to wild pollinators, and strongly suggests that imported honeybees are the main reservoir for diseases”. Trade in honeybees is controlled by the World Organisation for Animal Health, which has rules to promote free trade while restricting the spread of diseases. But Shardlow says governments must introduce strict hygiene regulations to protect wild pollinators, worth an estimated £500 million a year to the UK economy alone. Fürst says there is no immediate threat to individual crops, since most are pollinated by a variety of insects. “But to keep it that way we need to protect our bees and keep populations healthy and –Worry about the cargo you can’t see– diverse.” n
which is relatively cold – between about 200 °C and 400 °C – so it isn’t clear if they are really hot or not. To find out, Kari Cooper of the University of California, Davis, studied solidified lavas from Mount Hood, a potentially active volcano in Oregon that last erupted 220 years ago. With Adam Kent of Oregon State University in Corvallis, she isolated crystals from the lava. They were at least 21,000 years old, based on the radioactive decay of uranium, a “clock” that began ticking when they formed. There was far more strontium in the crystals’ cores than near their margins. That is odd, because at 750 ºC, the
temperature at which lava begins to melt, strontium would diffuse throughout crystals within a few thousand years. As it hadn’t done so, the crystals can have spent no more than 2800 years above 750 °C, and maybe just 140 years (Nature, doi.org/rhk). So what are the implications of the rock being solid? Magma must be mostly liquid for a volcano to erupt, says Cooper. “This process of ‘defrosting’ a magma body could
“The magma body could defrost before we get any other evidence that an eruption is imminent”
happen before we get any other evidence that an eruption is imminent.” However, a 2013 study suggested that magma chambers under some volcanoes remain molten for long periods, rather than melting just before they erupt (Geology, doi.org/ rgf). That means looking for melting would only help predict some eruptions, but they are often big ones. “Defrosting applies in general to crystal-rich eruptions,” says Christian Huber of the Georgia Institute of Technology in Atlanta. That includes the 1991 Mount Pinatubo eruption in the Philippines, one of the largest of the 20th century. Colin Barras n