For Tiptop Bee Health, Not All Pollens Are Created Equal

Hardworking honey bees might need the farmer's help to get a varied diet containing all the proteins, vitamins, minerals, fats and carbohydrates necessary for good bee health.

Nectar supplies carbohydrates, or sugars. Pollen supplies everything else. But sunflower pollen, one of the familiar honey bee's favorite foods, doesn't provide enough protein, according to tests by Agricultural Research Service scientists.

High crop yields depend on having healthy, effective pollinators, but bees that work only in sunflower fields are likely to become undernourished. As they lose strength, they may not do a good job in that crop or in other crops they are "hired" to pollinate later on.

Sunflower growers can help bees get the mix of nutrients they need by planting small areas of other crops such as canola, also known as rape, near sunflower fields. Or they can let weeds and wildflowers grow along field edges, beside ditches or among rock outcroppings.

Honey bees that pollinate only one greenhouse crop run a similar risk of nutrient deficiency. As a preventive measure, beekeepers can place protein supplements or high-protein pollen patties in the hive.

ARS scientists fed sunflower, sesame and canola pollen to about 125 European honeybees housed in indoor cages at the Carl Hayden Bee Research Center in Tucson, Ariz. Bees fed canola pollen lived 48 to 65 percent longer than those fed sesame or sunflower pollens. Justin O. Schmidt, in charge of the study, chose those crops because their planted acreages are increasing.

Scientific contact: Justin O. Schmidt, ARS Carl Hayden Bee Research Center, Tucson, Ariz., phone (520) 670-6481, ext. 109, fax (520) 670-6493, jschmidt@ccit.arizona.edu.