Despite progress in recent years on causes and cures, colony collapse disorder has wreaked havoc on honeybee colonies across the country.
A mysterious malady that has been killing honeybees en masse for several years appears to have expanded drastically in the last year, commercial beekeepers say, wiping out 40 percent or even 50 percent of the hives needed to pollinate many of the nation’s fruits and vegetables.
Which is like, yeah, big whoop, it’s just bees, right? Except that:
The Agriculture Department says a quarter of the American diet, from apples to cherries to watermelons to onions, depends on pollination by honeybees.
As reported previously, colony collapse disorder seems to have multiple causes. In the NY Times’ Room for Debate blog, several scientists and other bee experts offer their commentary on what we currently know about CCD and what’s being done about it.
Meanwhile, individual beekeeping operations have been damaged, some beyond repair because of this malady. Others have been able to recover. The overall picture is, however, not quite as bleak as the press and the blogosphere might lead you to imagine. Colony numbers in the U.S. show the resiliency of American beekeepers.
Have Spanish scientists found a cure for colony collapse disorder, which affects millions of honeybees around the world? The sole cause, according to the scientists, is a fungal parasite called nosema ceranae. This finding doesn’t jibe with the recent Scientific American article written by two American CCD investigators. They say that nosema is one factor out of many.
In the gut contents we found spores of nosema, single-celled fungal parasites that can cause bee dysentery. The spore counts in these and in subsequent samples, however, were not high enough to explain the losses. Molecular analysis of Hackenberg’s bees, performed by the other of us (Cox-Foster), also revealed surprising levels of viral infections of various known types. But no single pathogen found in the insects could explain the scale of the disappearance.
Update: Some beekeepers have solved bee death problems in their hives by using comb with smaller cell sizes.
In case you weren’t aware, and I wasn’t for a long time, the foundation in common usage by beekeepers results in much larger bees than what you would find in a natural hive. I’ve measured sections of natural worker brood comb that are 4.6mm in diameter. This 4.6mm comb was drawn by a hive of commercial Carniolans and this 4.7mm comb was drawn on the first try by a package of commercial Carniolans. What most beekeepers use for worker brood is foundation that is 5.4mm in diameter. If you translate that into three dimensions, instead of one, that produces a bee that is about half again as large as is natural. By letting the bees build natural sized cells, I have virtually eliminated my Varroa and Tracheal mite problems.
The cell size in commercially available combs has been increased over the years to increase the honey yield. (thx, brian)
In an article for Scientific American, two scientists who are working on the causes of colony collapse disorder (CCD) say that they and other researchers have made some progress in determining what’s killing all of those bees.
The growing consensus among researchers is that multiple factors such as poor nutrition and exposure to pesticides can interact to weaken colonies and make them susceptible to a virus-mediated collapse. In the case of our experiments in greenhouses, the stress of being confined to a relatively small space could have been enough to make colonies succumb to IAPV and die with CCD-like symptoms.
It’s like AIDS for bees…the lowered immunity doesn’t kill directly but makes the bees more susceptible to other illness. One the techniques researchers used in investigating CDD is metagenomics. Instead of singling out an organism for analysis, they essentially mixed together a bunch of genetic material found in the bees (including any bacteria, virii, parasites, etc.) and sliced it up into small pieces that were individually deciphered. They went through those pieces one by one and assigned them to known organisms until they ran across something unusual.
The CSI-style investigation greatly expanded our general knowledge of honeybees. First, it showed that all samples (CCD and healthy) had eight different bacteria that had been described in two previous studies from other parts of the world. These findings strongly suggest that those bacteria may be symbionts, perhaps serving an essential role in bee biology such as aiding in digestion. We also found two nosema species, two other fungi and several bee viruses. But one bee virus stood out, as it had never been identified in the U.S.: the Israeli acute paralysis virus, or IAPV.
Scientists are still trying to figure out what’s causing CCD, or Colony Collapse Disorder, a plague that’s killing off millions of bee across the United States. Among the possible culprits are a virus, increased vulnerability to disease due to breeding, overwork (hives of bees are trucked around the country for months to pollinate crops), increased exposure to all kinds of insecticides, and perhaps even all of the above.
Whatever the cause, Aaron Hirsh says, the way to keep our crops pollinated could be simple: restore habitats for wild bees near crops that need to be pollinated.
As the swift expansion of feral honeybees across the Americas shows, they are not especially picky about their habitat; most anything outside of parking lot or vast monoculture will do. And for native bees, habitat could be restored to suit the needs of whichever species are exceptionally good pollinators of local crops. Bumblebees, for instance, are the best pollinators of Maine blueberries, whereas blue orchard bees work well for California almonds.
Hirsh’s idea is reminiscent of Michael Pollan’s proposals for decreasing the present monoculture in American agriculture outlined in his recent books.
Update: See also Beekeeping Backwards. (thx, david)
Langstroth’s crucial insight — “I could scarcely refrain from shouting ‘Eureka!’ in the open streets,” he wrote of the moment of revelation — was the concept of “bee space.” He realized that while honeybees will seal up passageways that are either too large or too small, they will leave open passages that are just the right size to allow a bee to pass through comfortably. Langstroth determined that if frames were placed at this “bee-space” interval of three-eighths of an inch, bees would build honeycomb that could be lifted from the hive, rather than, as was the practice up to that point, sliced or hacked out of it. He patented L. L. Langstroth’s Movable Comb Hive in 1852. Today’s version consists of a number of rectangular boxes-the number is supposed to grow during the season-open at the top and at the bottom. Each box is equipped with inner lips from which frames can be hung, like folders in a filing drawer, and each frame comes with special tabs to preserve bee space.
So says Elizabeth Kolbert in an article about colony-collapse disorder, a bee disease that’s wreaking havoc on beehives and food production around the US. Bee space! I’m unsure whether similar research has been done to determine the proper “human space”, although the placement of houses in a suburb, tables in a restaurant, blankets at the beach, or social space in elevators might provide some clues as to the proper measurement.
But returning to the bees, a coalition of scientists working on the problem has found a correlation between bee deaths and Israeli acute paralysis virus. An infusion of bees from Australia in 2004 may also have contributed to the disorder’s development. Full details are available on EurekAlert.
Honeybee populations across the US are falling due to a mysterious disease. “Almond crops are immediately vulnerable because they rely on honeybee pollination at this time of year. And the insect decline could potentially affect other crops later in the year, such as apples and blueberries.”