Promiscuity in Bees

Beekeeper Jan TenBruggencate. Photo by Anne E. O’Malley

It may not work well in human society, but promiscuity is important in bees. Not promiscuity itself, actually, but rather, the genetic diversity robustness it helps create.

For Kaua’i, the only Hawaiian island that has not yet been infested with key bee predators like the varroa mite and the small hive beetle, diversity may be key to survival. Globally, these pollinators and honey-producers face the mysterious Colony Collapse Disorder, and some researchers are convinced the hives may benefit from genetic improvements in bee populations.

A new study on bees highlights the value of diversity. Researchers from Wellesley College and Indiana University, Bloomington, with the Netherlands Organisation for Applied Scientific Research, compared hives whose queens had mated once with hives whose queens had mated 15 times.

“What we observed in our work was that there was less likelihood of potentially pathogenic (disease-causing) bacteria showing up in genetically diverse honey bee colonies compared to genetically uniform colonies,” said co-author Irene Newton, quoted in Science Daily.

The research was printed in the online journal PloS ONE, under the title, “Characterization of the Active Microbiotas Associated with Honey Bees Reveals Healthier and Broader Communities when Colonies are Genetically Diverse.”

“It is our first insight into a means by which colony health could be improved by diversity,” said co-author Heather Matilla, quoted in Science Codex. “It shows one of the many ways that the function of a honey bee colony is enhanced when a queen mates promiscuously, which is an unusual behavior for social insects.”

But this isn’t the only research with a similar conclusion: Tunisian researchers A. Arbia and B. Babbay, of the Institut de la Recherche Veterinaire de Tunisie, note in a 2011 paper that genetic resistance is preferable to using antibiotics, fungicides, chemical mite control and other approaches to keep bees healthy and parasite-free.

“Several problems associated with this extended use of antibiotics and pesticides is leading to both short-term impacts on beekeepers and long-term effects on the ability of bees to evolve resistance toward their pathogens and favor the spread of more virulent pathogen strains,” they wrote in a Journal of Entomology paper, “Management Strategies of Honey Bee Diseases.”

In yet another bee study, this one published in 2007 in the Proceedings of the Royal Society/Biological Sciences researchers sprayed the deadly disease American foulbrood, on hives with queens that had mated once, and on hives that had numerous matings. They found that the promiscuous queens’ hives survived the disease better. (American foulbrood in the late 1930s killed off much of the territory’s honey industry.)

Authors Thomas Seeley and David Tarpy, in their article Queen promiscuity lowers disease within honeybee colonies wrote: “We found that, on average, colonies headed by multiple-drone inseminated queens had markedly lower disease intensity and higher colony strength at the end of the summer relative to colonies headed by single-drone inseminated queens.”

Their conclusion was that “loose” behavior by queens is actually an adaptation that makes for stronger hives.

Jan TenBruggencate, a beekeeper for less than a year, is an author and the former science writer for The Honolulu Advertiser. He operates a communications company, Island Strategy LLC. He serves on the board of the Kaua’i Island Utility Cooperative and on the County Charter Review Commission.