Blue orchard bees seen as a supplement to honeybees in almonds

By TIM HEARDEN

Capital Press

CHICO, Calif. -- Scientists are determining whether native blue orchard bees can be an effective alternative to honey bees in pollinating almonds and other crops.

The bees -- Osmia lignaria -- are known for being efficient pollinators of fruit trees, are easy to manage and rarely sting, according to the USDA's Agricultural Research Service.

As colony collapse disorder and other challenges have driven up the cost of renting honeybee hives for almond production, the scientists are eying the blue orchard bee as a supplement.

A project funded by the Almond Board of California placed bee boxes in almond orchards near Chico and Turlock, Calif., and is beginning to show results, said Sara Goldman Smith, a research associate for the University of California's integrated pest management program.

"What we were hoping to do is create some guidelines so that people who've never even heard of these bees" can use them, Goldman Smith told almond growers at a Chico seminar on Monday, Dec. 7.

By 2012, the ARS expects almond-bearing acreage in California to top 800,000, a sharp increase from the 680,000 acres of almonds farmed in 2004. The increase has helped drive up the price of honeybees from about $50 per hive in 2003 to as much as $170 per hive this year, the agency reports.

Data from the University of California study will complement the work of the USDA's Bee Biology and Systematics Laboratory in Logan, Utah, which has been gathering information about the blue orchard bee for about 40 years, researcher Glen Trostle said.

The bee proved beneficial to a cherry orchard in Utah, facilitating annual yield increases during a study from 1998 to 2003, Trostle said.

Blue orchard bees, or BOBs, have some advantages over honeybees, said Jim Cane, a research entomologist at the Logan lab. BOBs can forage in cooler weather, meaning they can pollinate early varieties of almonds, he said. Also, they're more efficient than honeybees at carrying pollen, he said.

However, the bees can't be left alone, Cane said. For one thing, while honeybees are migratory, blue orchard bees' nests have to be fixed in place for a season, so the bees must be given supplemental forage before and after the almond bloom, he said.

Also, the blue orchard bee lays about 30 eggs in a season, so population increases are slow. That means a grower or beekeeper needs to start with a large population and prevent losses, he said.

Cane recommended that people considering using the bees first become familiar with them by putting a nest close by and seeing how they behave.

Online

ARS blue orchard bee page: www.ars.usda.gov/Research/docs.htm?docid=18333