Skip to content



Media Contacts:
Dr. David Tarpy,
Matt Shipman, News Services

June 17, 2013

Researchers Find Genetic Diversity Key to Survival of Honey Bee Colonies


When it comes to honey bees, more mates is better. A new study from North Carolina State University, the University of Maryland and the U.S. Department of Agriculture (USDA) shows that genetic diversity is key to survival in honey bee colonies – meaning a colony is less likely to survive if its queen has had a limited number of mates.

“We wanted to determine whether a colony’s genetic diversity has an impact on its survival, and what that impact may be,” says Dr. David Tarpy, an associate professor of entomology at North Carolina State University and lead author of a paper describing the study. “We knew genetic diversity affected survival under controlled conditions, but wanted to see if it held true in the real world. And, if so, how much diversity is needed to significantly improve a colony’s odds of surviving.”

Tarpy took genetic samples from 80 commercial colonies of honey bees (Apis mellifera) in the eastern United States to assess each colony’s genetic diversity, which reflects the number of males a colony’s queen has mated with. The more mates a queen has had, the higher the genetic diversity in the colony. The researchers then tracked the health of the colonies on an almost monthly basis over the course of 10 months – which is a full working “season” for commercial bee colonies.

The researchers found that colonies where the queen had mated at least seven times were 2.86 times more likely to survive the 10-month working season. Specifically, 48 percent of colonies with queens who had mated at least seven times were still alive at the end of the season. Only 17 percent of the less genetically diverse colonies survived. “48 percent survival is still an alarmingly low survival rate, but it’s far better than 17 percent,” Tarpy says.

“This study confirms that genetic diversity is enormously important in honey bee populations,” Tarpy says. “And it also offers some guidance to beekeepers about breeding strategies that will help their colonies survive.”

The paper, “Genetic diversity affects colony survivorship in commercial honey bee colonies,” was published online this month in the journal Naturwissenschaften. Co-authors of the study are Dr. Dennis vanEngelsdorp of the University of Maryland and Dr. Jeffery Pettis of USDA. The work was supported by the USDA Cooperative State Research, Education and Extension Service, the USDA Agricultural Research Service, the North Carolina Department of Agriculture and Consumer Services and the National Honey Board.


Note to Editors: The study abstract follows.

“Genetic diversity affects colony survivorship in commercial honey bee colonies”

Authors: David R. Tarpy, North Carolina State University; Dennis vanEnglesdorp, University of Maryland; and Jeffery S. Pettis, USDA-ARS Bee Research Laboratory

Published: June 2013, Naturwissenschaften

DOI: 10.1007/s00114-013-1065-y

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 (m e ) 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 e  ≤ 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 withe  > 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.

David R. Tarpy
Associate Professor and Extension Apiculturist
Department of Entomology, Campus Box 7613
North Carolina State University
Raleigh, NC  27695-7613


  • Swarms
    • Still a chance of colonies swarming this month
      • Check for swarm cells weekly
      • Inspect for other signs of swarm preparation
    • Combine weak colonies with those showing signs of swarm preparation
  • Honey flow
    • Continue to add honey supers of drawn comb when needed
    • Keep doing until honey flow ends
      • No need to add honey supers once the flow is over
    • Removed capped honey after about June 15th
      • Removed two weeks after honey flow ends
  • Honey extraction
    • Extract honey within four days after removing from colony
      • Store in warm 90° F, dust-free, screened room
    • Store in a freezer if you are not going to extract within a four day time frame
    • Save wax cappings
      • Bees can reuse
      • Make candles
      • Sell for credit to some supply companies
  • Inspect hive
    • Bi-weekly check on health of queen and strength of colony
    • Monitor hive activities


  • Prepare to move bees if pollinating other crops
    • Maximize summer honey flow
  • No need to feed
    • Gathering plenty of nectar and pollen when foraging
    • Provide water
      • Use a shallow pan with rocks in it
        • Bees will stand on rocks to drink so they don’t fall in
        • Bird baths also work well so bees don’t get in pet’s water dish or neighbor’s pool
  • Create more colonies by splitting those large and strong enough
    • Use some created queen cells to produce viable queens for the split colonies

Four Oaks is determined to put a honey bee ordinance in effect at the next meeting (June 10, 2013 @ 7:30pm). The one they presented at the last meeting was very stringent.  It would have to have all landowners within 450 ft. radius agree to allow anyone to keep bees.

As Dr. Ambrose recommended, they may go and modify Cary's.  Sherry (town clerk) called me and said Cary's allows from 1 to max of 3 hives per lot, based on the size of the lot.  When I Googled Cary's honeybee ordinance, the ordinance it came up with was 2 hive to 8 hive maximum - and that's what Charles Heatherly said Cary went with.

So, I believe they will present the 1-3 hive range at the June 10th town council meeting. It is an open forum for public comment, so anyone (even people in another town and county) may speak for or against the ordinance and for no ordinance.

So, if anyone would like to show up at the Four Oaks town meeting, they are welcome to show up and speak, or just show up.It is at 304 N. Main Street, Four Oaks, NC on June 10, 2013 @ 7:30 pm. If people would like more information, they can email me at alhildreth@embarqmail.,com

-- Al Hildreth

June 8- Saturday 9am - 1pm

Swarm Out Session:

Queen Rearing Demo with Rick Coor of Spring Bank Bee Farm

- Hosted by Tom & Kim Underhill of Big Oak Apiary of Raleigh, of John 15:5 Farm located at 2633 Branch Road in Raleigh, NC 27610

- Rick will be here in Raleigh, demonstrating techniques of Queen Rearing, grafting, processing, and all the steps in between required to raise your own quality queens.

- Rick is a pillar of the Bee Keeping Community and has invaluable knowledge to share. Rick believes and lives by paying it forward. He makes all efforts to help, mentor and assist bee keepers of all levels to further their bee keeping education, techniques, and experiences.

-Cost: $10.00 per person – with the proceeds to be donated to Dr. Tarpy’s Bee Research Lab.

- Register by emailing Tom & Kim Underhill:

- Cash only please