Among bees, the looser win

Queen bees need many, varied partners, researchers say

RALEIGH -- In the pitiless world of honeybees, it pays to be a floozy.

Research at N.C. State University shows that the happiest, most productive bee colonies are ruled by queens with roving eyes and a taste for insect whoopee.

For a beekeeper, this means that a honey harvest's success can be tied to the variety and number of the queen's partners.

It also spells good news for bee health in a perilous time for the insects. Nationally, colonies are getting wiped out by a mysterious collapse, and North Carolina has seen hives hit hard by parasitic mites.

The NCSU study shows a link between queen quality and healthy colonies. But in a larger sense, the professors' work spells validation for promiscuity in at least one corner of the animal kingdom.

The queen bee is born into a world that closely resembles the British monarchy circa 1600.

One question -- who shall be queen? -- dominates bee life, with workers always ready to kill off an unproductive monarch.

A queen gives off pheromones that block the urge to kill and create new queens, said Christina Grozinger, professor of insect genomics and co-author of the study.

The idea that spawned the study suggested that the more partners the queen had, and the more variety in her mates, the more compelling the pheromone.

So to the test, which took about two years in an artificial bee colony at Lake Wheeler.

Half of about 60 bees in the study got a microliter of semen from a single drone. The others got 10 times as much from 10 times as many.

Inseminating the bees was a specialty of David Tarpy, assistant professor of entomology and co-author of the study. To do it, the bees were knocked out using carbon dioxide and probed with a tiny needle. "You have to maneuver it in there and kind of wiggle it until it's in the right position," Grozinger said.

The results: Queens with multiple mates drew crowds that were 1 1/2 times as large. So if a single-mate queen drew 10 bees, a more libertine bee attracted 15.

The results repeated themselves when the researchers placed an extract from the bees' pheromone glands on a slide. Pheromones with variety proved most popular, evidence of the queen's history.

"You'd think the bee would want control no matter what and not let on how many times she mated," Grozinger said. "But she does. The workers seem to know that it's better."

The upshot is better bee colonies, said Freddie-Jeanne Richard, a postdoctoral research associate in the Department of Entomology, also involved in the study.

Fighting mites

A pair of parasitic mites have caused the number of managed hives in North Carolina to drop from 180,000 to 100,000 since the mid-1980s.

Beekeepers complain that their queens last just a year, Richard said. But with happy workers not bent on regicide, they can last three. And if a queen mates more freely, she has a better chance at picking up mite-resistant traits that neighboring bees could carry.

It's hard for a beekeeper to know a queen's mating history in advance, said Charles Heatherly, president of the N.C. Beekeepers Association. But if a colony starts drawing all manner of bees, both black and yellow, it's a good chance there's some variety in the queen's mix.

To really select a queen with a good history, Grozinger said, you'd need to inseminate her.

It's the kind of science that can draw giggles from the professors whose work appeared this month in the online science journal PLoS One. Talking about their work, it was hard for them not to notice parallels to the human world.

The scarlet letter of the insect kingdom isn't A, it would seem.

It's B.