Promiscuity Increases Genetic Diversity Among Honey Bees, Keeps Colony Healthy

For honey bees, promiscuity leads to genetic diversity which determines the survivability of the colony, according to a new study.

The study was conducted by researchers from North Carolina State University, the University of Maryland and the U.S. Department of Agriculture (USDA), who found that fewer queen bees lead to collapse of the colony.

Previous research has shown that genetic diversity can help honey bees fight-off pests, pathogens and parasites. Promiscuity has also helped certain species of bees avoid inbreeding.

Researchers obtained samples from 80 commercial colonies of honey bees (Apis mellifera) for the study. They then assessed the genetic diversity of each colony. The study showed that higher number of mates for the queen resulted in higher genetic diversity. The researchers then looked at each colony's health during a "full working season" which is a busy time for the honey bees.

"We wanted to determine whether a colony's genetic diversity has an impact on its survival, and what that impact may be. 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," said Dr. David Tarpy, an associate professor of entomology at North Carolina State University and lead author of the present study.

The study showed that the chances of surviving the 10-month long working season was 2.86 times higher for colonies where the queen had mated at least seven times. About 48 percent of the colonies that had queens that mated several times survived the working season when compared to 17 percent of the colonies where the queen had mated fewer times.

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

The study paper, "Genetic diversity affects colony survivorship in commercial honey bee colonies," is published the journal Naturwissenschaften.