Decline of the Honeybee

More than 25 percent of the country's honeybee population has disappeared over the last several winters - tens of billions of bees. In as little as two days, hives go from healthy and active to dead and gone, and nobody knows why. While honeybees are best known for providing us with that golden, sweet viscous fluid called honey, they also provide another invaluable service; they pollinate fruits, vegetables, legumes, and other types of food-producing plants. Honeybees are responsible for $15 billion in U.S. agricultural crops each year. Imagine—one out of every three bites of food an average American eats is directly attributed to honeybee pollination. Consequently, their disappearance poses a serious risk to our natural food supply.

People have many theories on the cause of the bee disappearances, everything from genetically modified crops to “the rapture,” but researchers say the losses are caused by Colony Collapse Disorder or CCD. When a hive experiences CCD, the honeybees mysteriously leave their hive and die, leading ultimately to death of the colony. First noticed in late 2006 in North America, CCD symptoms have been reported by more than 35 states across the U.S. and in many other countries. Large bee losses are not unheard of. The first published record of a similar disorder appeared in 1869 and has been occurring for over 100 years. However, researchers think they are dealing with something new, or at least something previously unidentified.

Researchers aren’t sure exactly what causes CCD, but believe there may be many factors contributing to the problem, including viruses, mites, chemical exposure and poor nutrition. One factor that has been identified with CCD is a virus known as Israeli Acute Paralysis Virus (IAPV), which has been found in nearly all hives affected by CCD. A possible scenario is that CCD is triggered by various stress factors in bees infected with IAPV. Research is currently underway to test this hypothesis.

Bee colonies have been under stress in recent years as more beekeepers have been forced to ship trucks full of bees across the country in search of pollination work. These bees may also suffer from a diet that includes artificial supplements, concoctions similar to energy drinks and power bars. In several states, suburban sprawl has limited the bees’ natural forage areas.

Jeff Pettis, a U.S. Department of Agriculture researcher, has been tracking the bee die off. "We know some things that are contributing, but we can't point to a single factor as a cause," Pettis said. Pettis, along with Diana Cox-Foster, an entomologist at Pennsylvania State University, are leading a team of researchers who are searching for answers to explain CCD.

As researchers frantically search for answers, concerns also mount among public officials. Almonds, a $2-$3 billion crop, are the first to be jeopardized by the bee die-off, but apple trees along with cucumber, melon, cherry and berry crops follow shortly after. “There are so many of our crops that require pollinators,” said California Representative Dennis Cardoza. “We need an urgent call to arms to try to ascertain what is really going on here with the bees, and bring as much science as we possibly can to bear on the problem.”

The researchers have collected samples of bees from declining hives or colonies in several states and have begun bee autopsies and genetic analysis. The genetic testing being performed at Columbia University has revealed the presence of several unknown micro-organisms, as well as a fungi normally found in humans whose immune systems have been suppressed by Acquired Immune Deficiency Syndrome or cancer. This suggests that something is weakening the bees’ immune system.

Samples have also been sent to an Agriculture Department laboratory in North Carolina to screen for 117 chemicals. Of greatest interest are the systemic chemicals that are able to pass through a plant’s circulatory system and move to the new leaves or flowers, where they would come in contact with bees. One such chemical is imidacloprid, a compound commonly used in the U.S. and in Europe to treat seeds, to protect residential foundations against termites, and to keep home lawns and golf courses green. This chemical was banned by the French government in 1999 for use on sunflowers and later on corn, after French beekeepers reported large losses of their bees and complained about the use of imidacloprid, sold under the brand name Gaucho. While not killing the bees outright, the chemical was causing them to be disoriented and stay away from their hives, leading them to die of exposure to the cold. The beekeepers labeled the syndrome “mad bee disease.”

In recent years, the country’s bee population has been hurt by the varroa mite, a tiny parasitic bug which destroyed more than half of some beekeepers’ hives and devastated most wild honeybee populations. But researchers have ruled the varroa mite as a single cause for the high losses. They have also discounted the possibility that poor diet alone could be the culprit. And, because the bees are not showing symptoms typically associated with toxins, they have ruled out the possibility that the cause could be bees feeding from a commonly used genetically modified crop. The researchers did emphasize that feeding supplements produced from genetically modified crops, such as high-fructose corn syrup, need to be studied.

Scientists say the process is painstaking and that answers could be months away. “Clearly there is an urgency to solve this,” Dr. Cox-Foster said. “We are trying to move as quickly as we can.”