Where Are All the Honey Bees?

This spring, dismay is widespread among nomadic beekeepers who crisscross the United States with beehives in tow to support the pollination of such crops as almonds in the Central Valley of California, or widely-grown forage like alfalfa.

When the beekeepers opened their hives to check on the well-being of the colony housed in each hive, they discovered a frightening number of the hives empty of adult bees with no sign of the usual pests such as wax moths or hive beetles.

Sometimes a queen remained in the hive, with a tiny court.

Usually the hive still held honey and bee bread.

Honey is evaporated flower nectar, reduced from nectar brought back to the hive by worker bees. The nectar is stored in cells of the honeycomb. Worker bees speed up evaporation of water from the nectar by flapping their wings. Once the amount of water drops to 18%, the bees are happy and cap off the cell until the honey is needed for food.

Bee bread is a mixture of honey and pollen, fed to larva that will grow into workers or drones. To grow into a queen bee, a larva must be fed royal jelly, which mixes pollen with a higher percentage of honey and "mandibular-gland secretions" -- bee spit.

Some beekeepers have lost few colonies. Other beekeepers report losses as high as 90% of their hives.

Loss of bee colonies isn't new -- beekeepers frequently see colonies die off.

Alarm bells are ringing this year because of the size of the loss, and how far-reaching it is.

European beekeepers are seeing a similar collapse in honey bee colonies. (Populations isolated by distance or oceans are as yet not effected. For instance, New Zealand has not seen a problem.)

Even stay-at-home beekeepers in the United States are now reporting losses, many of more than half their colonies.

As yet, no one knows the cause. After study, researchers have ruled out several possible causes. It's not artificial feeding, antibiotics or mite poisons, the use the bees were put to (that is, pollination of crops or honey production), or the source of queen bees.

Researchers think that there may be more than one cause. They are now checking for contamination of the wax, food stores or the bees themselves. Perhaps some unknown disease agent or parasite is making the adult bees sick, or a lack of proper food making them weak. Stress from some unknown cause may play a part, as might lack of genetic diversity in the current honey bee population.

No reports have been received of a similar drop-off in colonies of Africanized honey bees (Apis mellifera scutellata Lepeletier).

Honey bees are not the only natural pollinators. Bumblebees and paper wasps, even hummingbirds, also serve as natural pollinators. (Carpenter bees, in turns out, take nectar but don't help much with pollination.) However, these alternative pollinators are not as easily tamed as the European honey bee. Some lead solitary lives rather than living in colonies, others defend their nests too strongly. None combine all the good points -- a placid disposition, ease of upkeep, crop pollination, production of abundant honey and wax -- of the European honey bee.

Additional Resources:

C.E.H. Wiedel. Collected Fact Sheets & Photographs on Insects. URL: (http://www.cehwiedel.com/factualreports/Fauna/Insect/)

Colony Collapse Disorder Working Group. Associated Content. URL: (http://www.ento.psu.edu/MAAREC/pressReleases/ColonyCollapseDisorderWG.html)

Honey Bee Genome Sequencing Consortium. Associated Content. URL: (http://www.hgsc.bcm.tmc.edu/projects/honeybee/)