Author
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TARPY, DAVID - North Carolina State University |
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Pettis, Jeffery |
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VANENGELSDORP, DENNIS - University Of Maryland |
Submitted to: Naturwissenschaften
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/22/2013 Publication Date: 8/1/2013 Citation: Tarpy, D.R., Pettis, J.S., Vanengelsdorp, D. 2013. Genetic diversity affects colony survivorship in commercial honey bee colonies. Naturwissenschaften. 100(8): 723-728. Interpretive Summary: Honey bee queens mate with a high number of males (an average of 12 males) thus increasing the diversity of the genetic makeup of workers within a colony. This diversity has been shown to give significant adaptive advantages that result in increased colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequency of queens and the genetic diversity within a colony in three commercial operations to determine a connection between colony health and productivity, particularly the likelihood of queen replacement and colony survival in intensively managed beehives. We found that average number drones to be 13.6±6.76, which is not significantly different between colonies that replaced their queens and those that did not. However, colonies with less genetic diversity were almost three times more likely to die by the end of the study when compared with colonies with more genetic diversity. This suggests that there are important benefits to queens with higher number of mates in managed honey bees, although the exact mechanisms that make up these benefits are not fully understood. This information adds to our understanding of why colonies may die and will be used by beekeepers to improve colony survival. Technical Abstract: Honey bee (Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency (me) of this population of honey bee queens to be 13.6±6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with me=7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with me>7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated. |