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Where have all the bees gone?
This week–
Where have all the bees gone? MICHAEL REILLY, SAN FRANCISCO
IT IS a vanishing on the scale of entire cities. Late in 2006, commercial beekeepers in Florida began noticing alarming numbers of their bees had gone missing. Bustling colonies, tens of thousands strong, were emptying in a matter of days. Systematic searches for dead bees around the colonies mostly drew a blank. “Imagine waking one morning to find 80 per cent of the people in your community are just gone,” says May Berenbaum of the University of Illinois, Urbana-Champaign.
070324_N_p10_11.indd 10
Before long 22 states were reporting similar stories, raising fears that bees were in serious trouble – potentially a big disaster for farmers since bees pollinate crops worth $14 billion each year in the US. There is no shortage of potential culprits; European honeybees make up the vast majority of commercial stocks in the US and they are susceptible to myriad viral and fungal blights and two forms of parasitic mites, one of which wiped out about half of the American honeybee population in the 1980s. Yet, in this instance, the precise cause of
the sudden decline, dubbed “colony collapse disorder”, remains elusive. The pattern of disappearance offers few clues, since CCD appears to be widespread and plagues nonmigrating colonies as well as those that are moved from place to place to pollinate crops. Berenbaum and another Illinois researcher, Gene Robinson, are trying to work out whether pathogens or pesticides are behind CCD with the help of the newly sequenced honeybee genome. “If it’s a pathogen, genes related to immune response would be overexpressed,” says Berenbaum. “If the bees are reacting to a pesticide, we’d expected to see up-regulation
“Bustling honeybee colonies, tens of thousands strong, were emptying in only a matter of days”
of detoxification genes.” Meanwhile, Nancy Ostiguy and researchers from Pennsylvania State University, University Park, are looking for signs of a new virus or fungus. According to Marla Spivak of the University of Minnesota, St Paul, the nature of the beekeeping industry itself could be adding to the problem. For example, she says, in California, where bees are transported each year to pollinate almond plantations, “there are about a half a million acres that need pollination, but growers rent about a million bee colonies”. Such high density could create competitive stress for bee colonies. In their quest for pollen and nectar, members of a single colony typically range over several hectares. To avoid food shortages, beekeepers often supplement hive production with high-fructose corn syrup, which
20/3/07 16:19:30
KIM TAYLOR/NATURE PL
070324_N_p10_11.indd 11
may poison the bees if the syrup is not properly prepared. Yet there is no evidence that CCD is related to poisoning, which would typically lead to a faster and more localised die-off. Spivak also points out that many beekeepers weren’t affected by this year’s disappearance, and no one is quite sure of the extent of CCD’s impact since the true number of bee colonies in the US is unknown. Perhaps the real lesson from CCD, says Jerry Bromenshenk of the University of Montana, is that standardised data about honeybees is not available to help researchers determine if they are dealing with a new and potentially disastrous pathogen. Daniel Weaver, president of the American Beekeeping Federation, says that between one-quarter and one-half of America’s roughly –We’ll be lost without them– 2000 commercial keepers have
reported losses that fit the description of CCD. Despite the sketchy details, federal lawmakers have begun taking note of the industry’s plight. The House Agriculture Committee has scheduled a hearing on CCD for 29 March at which Weaver, Berenbaum and members of the beekeeping community are due to testify. Weaver plans to ask the Department of Agriculture to double its funding for the nation’s four bee research labs; only $8 million out of a $93 billion budget for US agriculture goes on bees. Spivak believes acknowledging that commercial agriculture has to change its ways may be as important as any extra funding. “It’s an unsustainable system. The bees are really at the base of a lot of agriculture and if they go tumbling down, what’s going to happen on top of that?” ●
20/3/07 4:04:24 pm
Where have all the bees gone? MICHAEL REILLY, SAN FRANCISCO
IT IS a vanishing on the scale of entire cities. Late in 2006, commercial beekeepers in Florida began noticing alarming numbers of their bees had gone missing. Bustling colonies, tens of thousands strong, were emptying in a matter of days. Systematic searches for dead bees around the colonies mostly drew a blank. “Imagine waking one morning to find 80 per cent of the people in your community are just gone,” says May Berenbaum of the University of Illinois, Urbana-Champaign.
070324_N_p10_11.indd 10
Before long 22 states were reporting similar stories, raising fears that bees were in serious trouble – potentially a big disaster for farmers since bees pollinate crops worth $14 billion each year in the US. There is no shortage of potential culprits; European honeybees make up the vast majority of commercial stocks in the US and they are susceptible to myriad viral and fungal blights and two forms of parasitic mites, one of which wiped out about half of the American honeybee population in the 1980s. Yet, in this instance, the precise cause of
the sudden decline, dubbed “colony collapse disorder”, remains elusive. The pattern of disappearance offers few clues, since CCD appears to be widespread and plagues nonmigrating colonies as well as those that are moved from place to place to pollinate crops. Berenbaum and another Illinois researcher, Gene Robinson, are trying to work out whether pathogens or pesticides are behind CCD with the help of the newly sequenced honeybee genome. “If it’s a pathogen, genes related to immune response would be overexpressed,” says Berenbaum. “If the bees are reacting to a pesticide, we’d expected to see up-regulation
“Bustling honeybee colonies, tens of thousands strong, were emptying in only a matter of days”
of detoxification genes.” Meanwhile, Nancy Ostiguy and researchers from Pennsylvania State University, University Park, are looking for signs of a new virus or fungus. According to Marla Spivak of the University of Minnesota, St Paul, the nature of the beekeeping industry itself could be adding to the problem. For example, she says, in California, where bees are transported each year to pollinate almond plantations, “there are about a half a million acres that need pollination, but growers rent about a million bee colonies”. Such high density could create competitive stress for bee colonies. In their quest for pollen and nectar, members of a single colony typically range over several hectares. To avoid food shortages, beekeepers often supplement hive production with high-fructose corn syrup, which
20/3/07 16:19:30
KIM TAYLOR/NATURE PL
070324_N_p10_11.indd 11
may poison the bees if the syrup is not properly prepared. Yet there is no evidence that CCD is related to poisoning, which would typically lead to a faster and more localised die-off. Spivak also points out that many beekeepers weren’t affected by this year’s disappearance, and no one is quite sure of the extent of CCD’s impact since the true number of bee colonies in the US is unknown. Perhaps the real lesson from CCD, says Jerry Bromenshenk of the University of Montana, is that standardised data about honeybees is not available to help researchers determine if they are dealing with a new and potentially disastrous pathogen. Daniel Weaver, president of the American Beekeeping Federation, says that between one-quarter and one-half of America’s roughly –We’ll be lost without them– 2000 commercial keepers have
reported losses that fit the description of CCD. Despite the sketchy details, federal lawmakers have begun taking note of the industry’s plight. The House Agriculture Committee has scheduled a hearing on CCD for 29 March at which Weaver, Berenbaum and members of the beekeeping community are due to testify. Weaver plans to ask the Department of Agriculture to double its funding for the nation’s four bee research labs; only $8 million out of a $93 billion budget for US agriculture goes on bees. Spivak believes acknowledging that commercial agriculture has to change its ways may be as important as any extra funding. “It’s an unsustainable system. The bees are really at the base of a lot of agriculture and if they go tumbling down, what’s going to happen on top of that?” ●
20/3/07 4:04:24 pm