To bee or not to bee

A new study has found that the mystery behind queen honeybees extreme promiscuity serves the purpose of producing more productive colonies. Cornell researchers Tom Seeley and Heather Mattila have found that queen honeybees mate with dozens of males in order to produce genetically diverse colonies that are far more productive and lasting than genetically uniform colonies produced by monogamous queens.

"An intriguing trait of honeybee species worldwide is that each honeybee queen mates with an extraordinarily high number of males," the authors said. In every honeybee species, say the researchers, queens mate with numerous males. For example, the European honeybee, the common species in North America, mates with six to 20 mates on average, while the giant honeybee in Asia has a reported record of 102 mates.

To study the reasons for honeybees’ promiscuity, the Cornell biologist inseminated 12 queens with sperm from 15 drones, a different set for each, and nine additional queens with sperm from a single drone, but a different one in each case. They then prompted the hives to swarm in early June to form new colonies.

"After only two weeks of building new nests, the genetically diverse colonies constructed 30 percent more comb, stored 39 percent more food and maintained foraging levels that were 27 to 78 percent higher than genetically uniform colonies," said Mattila.

By the end of the summer, the genetically varied colonies had five times more bees, eight times more reproductive males and heavier average body weights, mostly because of larger amounts of stored food. By winter’s end, 25 percent of the genetically diverse colonies survived to their one-year. But all of the genetically uniform hives starved to death.

"These differences are noteworthy considering colonies had similarly sized worker populations when they were first formed. Undoubtedly, our results reveal enormous benefits of genetic diversity for the productivity of honeybee colonies," Mattila said. — ANI

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