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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Publications at this Location » Publication #262356
Title: Foraging range of honey bees, Apis mellifera, in alfalfa seed production fields

Author
item Hagler, James
item MUELLER, SHANNON - University Of California - Cooperative Extension Service
item TEUBER, LARRY - University Of California
item Machtley, Scott
item DEYNZE, ALLEN - University Of California

Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2011
Publication Date: 11/2/2011
Citation: Hagler, J.R., Mueller, S., Teuber, L.R., Machtley, S.A., Deynze, A.V. 2011. Foraging range of honey bees, Apis mellifera, in alfalfa seed production fields. Journal of Insect Science. 11:144.

Interpretive Summary: Alfalfa is one of the most important crops grown in the US that requires bee pollination for seed production. The introduction of herbicide-resistant Roundup Ready® alfalfa in 2005 represented the commercialization of the first genetically engineered alfalfa variety. While herbicide-tolerant alfalfa varieties have advantages in terms of weed control, they could pose a problem for the alfalfa seed industry if the gene is unintentionally moved by pollinators from transgenic to nearby non-transgenic alfalfa fields. Knowledge of bee foraging behavior and the extent of pollen-mediated gene flow between alfalfa seed production fields are needed to minimize adventitious presence of the modified gene in non-genetically engineered alfalfa fields. Our goal was to quantify bee dispersal patterns throughout a commercial alfalfa seed production area that contained Roundup Ready and conventional alfalfa. To accomplish this goal, honey bee self-marking devices loaded with various distinct powders were placed at the entrances of 112 honey bee hives located in nine apiaries within a 15.2 km2 study area. The bees exiting the hives in each apiary were uniquely marked so that the apiary of origin and the distance traveled by the field-collected bees could be pinpointed. The distances traveled by marked bees ranged from 45 to 5,983 m. On average, marked bees were recovered about 800 m from their apiary of origin and the recovery rate of marked bees decreased exponentially as the distance from the apiary increased. Ultimately these data will be correlated with seed harvest data to identify the extent of pollen-mediated gene flow from Roundup Ready to conventional alfalfa.

Technical Abstract: A study was conducted in 2006 and 2007 designed to examine the foraging range of honey bees, Apis mellifera (Hymenoptera: Apidae) in a 15.2 km2 area dominated by a 128.9 ha glyphosate-resistant Roundup Ready® alfalfa seed production field and several non-Roundup Ready seed production fields (totaling 122.2 ha). Each year honey bee self-marking devices were placed on 112 selected honey bee colonies originating from nine different apiary locations. The bees exiting the hives in each apiary were uniquely marked so that the apiary of origin and the distance traveled by the marked (field-collected) bees could be pinpointed. Honey bee self-marking devices were installed on 14.4 and 11.2% of the total hives located within the research area in 2006 and 2007, respectively. The frequency of field-collected bees possessing a distinct mark was similar, averaging 14.0% in 2006 and 12.6% in 2007. A grand total of 12,266 bees were collected from the various alfalfa fields on seven sampling dates over the course of the study. The distances traveled by marked bees ranged from a minimum of 45 m to a maximum of 5,983 m. On average, marked bees were recovered about 800 m from their apiary of origin and the recovery rate of marked bees decreased exponentially as the distance from the apiary of origin increased. Ultimately these data will be correlated with seed harvest data to identify the extent of pollen-mediated gene flow from Roundup Ready to conventional alfalfa.