May 7 (Bloomberg) -- Global honeybee supplies are tightening from food needs that are rapidly outpacing growth in the number of insects, with diseases such as Colony Collapse Disorder a lesser factor, according to a study in the journal Current Biology.

Production of crops dependent on commercial bees worldwide has increased sixfold over the past 50 years, while pollinator numbers gained only 45 percent, the researchers, including Lawrence Harder from Canada’s University of Calgary, wrote in the study, which was released today.

Honeybees have seen their populations fall in some areas, including the U.S., largely because more honey is being imported. At the same time, the insects are in more demand because of increases in crops such as almonds, mangos and plums, which may experience shortages in the future, the researchers said.

A supply problem is a concern, “because the cultivation of pollinator-dependent crops is growing several times faster, which is unsustainable,” Harder wrote in an e-mail.

Possible solutions include creating self-pollinating versions of what are now bee-dependent crops, reducing human demand for certain foods, and developing other bee species as commercial pollinators, he said.

Companies that use pollinated crops in their products, including General Mills Inc. and Clorox Co. have been concerned about bee loss in the wake of Colony Collapse Disorder, which has killed billions of U.S. and European bees since 2006. Honeybees pollinate about $15 billion of U.S. crops. Their absence could create $75 billion in economic losses, then- Agriculture Secretary Mike Johanns said in 2007.

Colony Collapse Disorder

Colony Collapse and other diseases, while devastating to beekeepers, have less to do with U.S. bee losses than economic trends, according to the study. The maladies have not stopped an increase in worldwide bee numbers that was only interrupted by the dissolution of the Soviet Union in the early 1990s, which prompted a decline in beekeeping in Eastern Bloc nations.

“American beekeepers are leaving the industry largely because honey is being produced at lower cost elsewhere,” Harder wrote in his e-mail.

A greater long-term challenge to bee supplies is rising cultivation of high-value crops such as guavas, cashew nuts and papayas, according to the researchers. As more people eat more of those foods, stress on honeybee populations increase, they said.

Not Surprised

The overall increase in honeybee numbers is not surprising, given the rise of honey production in China, Argentina, Canada and other places that once had fewer bees, said Dennis vanEngelsdorp, the president of the Apiary Inspectors of America in Harrisburg, Pennsylvania. Losses anywhere remain a “grave concern,” because of the expense beekeepers face when their colonies die, he said.

Bees are essential to keep pollinator-dependent crops healthy. Fruit-pollinated products are found in items such as Haagen-Dazs ice cream from General Mills. Lip balm made by Burt’s Bees Inc., a unit of Clorox Co., contains wax from the honeycombs of beehives.

Marcelo Aizen from the Universidad Nacional del Comahue in Buenos Aires was co-author of the study with Harder.

To contact the reporter on this story: Alan Bjerga in Washington at abjerga@bloomberg.net

Last Updated: May 7, 2009 12:02 EDT