An Alternative to Honey Bees for Pollination
The IssueManaging bees for pollination is becoming more difficult as beekeepers face challenges from the Africanized honey bee, the Red Imported Fire Ant, Varroa and tracheal mites and several other pests and diseases. Colony strength, winter survival and restrictions on movement of bees in to and out of the state all affect the economics of beekeeping. Growers who rely on honey bees for pollination are concerned about future availability of bees as well as increasing costs for pollination.
Leafcutter bees are used for pollination on certain crops in Canada and the Pacific Northwest, but they had not been used in California due to their higher cost and more intensive management requirements. If leafcutter bees could be used to pollinate several commodities in this area, there would be greater incentive to establish the necessary infrastructure, the cost would go down, custom pollinators might become involved and more growers could take advantage of the leafcutter bee's superior pollinating activity on certain crops.
What Has ANR Done?Leafcutter bee pollination was evaluated in alfalfa seed, almonds, boysenberries, kiwis, squash, strawberries and melons. In addition to pollination ability, bee survival and reproduction were evaluated. Alfalfa seed, strawberries and melons were the most promising crops for leafcutter bee pollination. Subsequent research helped determine best management practices for leafcutter bee pollination in these crops.Beekeepers and growers were informed at meetings, field days, and in newsletters.
Leafcutter bees are an alternative to honey bees for pollinationAlfalfa seed growers achieved significantly higher yields when leafcutter bees were used alone or in combination with honey bees for pollination. Growers were able to set seed in difficult areas of the field more easily, and the pollination period was reduced because of this bee's efficiency. Strategies have been developed to maximize bee survival and pollination effectiveness. Several companies now provide custom leafcutter bee pollination for seed growers in California.
Leafcutter bees can successfully pollinate melons, but are no better than honey bees. The life cycle of the leafcutter bee is well matched to the bloom period of melons, and they can survive and reproduce under commercial production conditions. If honey bees become more expensive due to reduced availability, leafcutter bees may provide a suitable alternative. Research is under way to develop strategies to improve the effectiveness of leafcutter bee pollination in melons.
Strawberry growers do not currently pay for custom pollination. However, as the industry becomes more sophisticated and may have to compete for limited market share, leafcutter bee pollination may provide the quality and yield advantage that pays for itself.
Supporting Unit: Fresno CountyShannon Mueller, UCCE, 1720 S. Maple Avenue, Fresno, CA 93702 559-456-7261