(Beyond Pesticides, March 1, 2007)
In 24 states throughout the country, beekeepers have been shocked to find that bees have been inexplicably disappearing at an alarming rate, according to an article in the New York Times last week. This loss of honeybees threatens not only beekeeper livelihoods but also the production of numerous crops, including California almonds, one of the nation’s most profitable crops. Although the reasons for the honeybee disappearances are unknown, pesticides may be one of the culprits.
“I have never seen anything like it,” David Bradshaw, a California beekeeper, said. “Box after box after box are just empty. There’s nobody home.” Last month he discovered that half of his 100 million bees were missing. Beekeepers have fought regional bee crises before, but this is the first national affliction. Bees are flying off in search of pollen and nectar and simply never returning to their colonies. And nobody knows why. Researchers say the bees are presumably dying in the fields, perhaps becoming exhausted or simply disoriented and eventually falling victim to the cold.
As researchers scramble to find answers to the syndrome they have decided to call “colony collapse disorder,” growers are becoming openly nervous about the capability of the commercial bee industry to meet the growing demand for bees to pollinate dozens of crops, from almonds to avocados to kiwis.
A Cornell University study has estimated that honeybees annually pollinate more than $14 billion worth of seeds and crops in the United States, mostly fruits, vegetables and nuts. “Every third bite we consume in our diet is dependent on a honeybee to pollinate that food,” said Zac Browning, vice president of the American Beekeeping Federation. The sudden mysterious losses in honeybee populations highlight the critical link that honeybees play in the long chain that gets fruit and vegetables to supermarkets and dinner tables across the country.
The bee losses are ranging from 30 to 60 percent on the West Coast, with some beekeepers on the East Coast and in Texas reporting losses of more than 70 percent; beekeepers consider a loss of up to 20 percent in the offseason to be normal.
Along with recent stresses on the bees themselves and an industry increasingly consolidating smaller operations, some fear these losses may force a breaking point for even large beekeepers. Once the domain of hobbyists with a handful of backyard hives, beekeeping has become increasingly commercial. Over the last two decades, the number of beehives, now estimated by the U.S. Department of Agriculture to be 2.4 million, has dropped by a quarter and the number of beekeepers by half.
“There are less beekeepers, less bees, yet more crops to pollinate,” Mr. Browning said. “While this sounds sweet for the bee business, with so much added loss and expense due to disease, pests and higher equipment costs, profitability is actually falling.”
Some 15 worried beekeepers convened in Florida this month to brainstorm with researchers how to cope with the extensive bee losses. Investigators are exploring a range of theories, including viruses, pesticides, a fungus and poor bee nutrition. Mites have also damaged bee colonies, and the insecticides used to try to kill mites are harming the ability of queen bees to spawn as many worker bees. The queens are living half as long as they did just a few years ago.
Researchers are also concerned that the willingness of beekeepers to truck their colonies from coast to coast could be adding to bees stress, helping to spread viruses and mites and otherwise accelerating whatever is afflicting them.
The news of honeybee losses comes amidst a recent trend of declining pollinator populations. An October 2006 report by the National Research council found that long-term population trends for some North American pollinators including bees, birds, bats are “demonstrably downward.”
The issue of protecting pollinators from pesticides and other environmental hazards has been heating up recently. In a landmark decision, the Minnesota Supreme Court ruled that landowners who spray pesticides on tree groves can be held liable for damages to beekeepers neighboring apiaries (Anderson, et al. v. International Paper, March 2005). The case was brought by three beekeepers who raise bees for honey and sale. This ruling sets a standard that could have dramatic ramifications for pesticide use across the country. For more information on this issue, see “The Minnesota Honey Bee Battle” printed in the Spring 2006 issue of Pesticides and You.
According to Ohio State University, over 75 commonly used pesticides are highly or moderately toxic to bees. The following pesticides are highly toxic to bees: 2,4-D (Weed-B-Gone), abamectin (Zephyr), acephate (Orthene), azinphos-methyl (Guthion), bifenthrin (Capture), carbaryl (Sevin), carbosulfan (Advantage), chlormephos (Dotan), chlorpyrifos (Lorsban, Dursban), cyfluthrin (Baythroid), d-phenothrin (Sumithrin), demeton-s-methyl (Metasystox (i), (50-% Premix), diazinon (Spectracide), dichlorvos (DDVP), dicrotophos (Bibrin), dimethoate (Cygon, De-Fend), esfenvalerate (Asana XL), ethion (tech), (Ethanox), etrimfos (Ekamet), fenitrothion (Sumithion), fenpropathrin (Farmatox), fensulfothion (Dasanit), fenthion (Baytex), fenvalerate (DMSO), (Belmark), flucythrinate (Pay-Off), fonofos (Dyfonate), heptachlor (Fennotox), lindane (Lindane), malathion (Malathion 50, Malathion ULV), methamidophos (Monitor, Tamaron), methidathion (Supracide), methiocarb (Mesurol), methyl parathion (Penncap-M), mevinphos (Phosdrin), monocrotophos (Azodrin), naled (Dibrom), omethoate (Folimat), oxydemethon-methyl (Metasystox-R), oxydisulfoton (Disyston S), parathion (Bladan), permethrin (Ambush, Pounce), phosmet (Imidan), phosphamidon (Dimecron), propoxur (Baygon), pyrazophos (Afugan), resmethrin (Chrysron), tetrachlorvinphos (Gardona), and tralomethrin (Scout X-TRA). The following are moderately toxic: Acetochlor (Acenit), Aclonifen (Challenge), allethrin (Pynamin), alphacypermethrin (Fastac), ametryn(Evik), bromopropylate (Acarol), cinmethylin (Argold), crotoxyphos (Ciodrin, Decrotox), DCPA (Dacthal), diphenamid (Dymid), disulfoton (DiSyston, Ekanon), endosulfan (Thiodan), endrin (Hexadrin), ethoprop (Mocap), flufenoxuron (Cascade), fluvalinate (tau-fluvalinate), (Mavrik, Spur), formetanate hydrochloride (Carzol), mancozeb (Manzate, Dithane, Fore), methanearsonic acid (MAA), neburon (Granurex, Propuron), pebulate (Tillam), phorate (Geomet, Thimet), pirimiphos-methyl (Acetellic), sethoxydim (Poast), sulfosate (Touchdown), terbufos (Counter), thiocyclam hydrogen oxalate (Evisect), thiodicarb (Larvin, Nivral), and triforine (Denarin, Funginex).
The U.S. Senate (S.Res. 580) and the U.S. Department of Agriculture has designated June 24-30, 2007, as National Pollinator Week. The Pollinator Partnership offers resources, as well as a listing of Pollinator Week events happening across the country for those who want to be involved.