Why Male Honeybees Try to Blind Their Queens

You don't casually date a queen.

Most male honeybees only get one shot at it. And she doesn't have time for dinner.

So what does a humble drone do to make sure she always remembers him? Wear his best pin-striped suit? A bouquet of pollen-rich daisies?

Researchers at the University of California, Riverside, suggest he brings something a little darker to the party: a toxin that makes her go blind.

In a paper published in the journal eLife, scientists describe how honeybees are so keen to be the queen's one-and-only, they try to incapacitate her with toxins in their semen.

The goal isn't so much to impress the queen, but rather to ensure that the bee wins the sexual arms race over his many rivals. A drone's chances of packing the winning semen are greatly diminished by every other bee she mates with.

For the queen, the blindness is only temporary — lasting anywhere from 24 to 48 hours. But it may be just long enough to keep her from flying. And if she can't fly, good luck getting to the other dates on her busy schedule.

"The male bees want to ensure their genes are among those that get passed on by discouraging the queen from mating with additional males," Boris Baer, the study's lead author, notes in a press release sent to MNN. "She can't fly if she can't see properly."

No, that doesn't sound particularly gracious. But then again, honeybees aren't expected to survive the hookup.

In fact, if they score, they're dead. But that doesn't stop as many as 40 drones from trying to mate with her — all in mid-air, during what's called a "nuptial" fight.

Male bees scramble to hook up with the queen bee. And she rips their hearts out. Or rather, their endophallus. That's the part of every male honeybee that's inserted in the queen and, well, you know ... the birds and the bees and all that.

The thing is, the climax is so forceful, the torrent of semen ruptures the endophallus, leaving the tip inside the queen — and the male bee is presumably in shock over how the date could have gone so terribly wrong.

It doesn't last long. The queen's nuptial flight leaves a trail of withered, endophallus-less corpses behind.

Indeed, the queen is a busy bee — which may be why drone semen is such a heady cocktail.

That bodily fluid is engineered to slow her down, maximizing the chances of one particular bee's genes prevailing. To that end, the researchers identified a couple of proteins in the drone's bodily fluids. One of them attacks the sperm of other males, aiming to undermine the efforts of other suitors. The other protein, described for the first time in the study, goes to work on the queen's brain, affecting her vision.

To test its potency, researchers dosed a group of queens with bee semen. A second group of queens was given a saline solution. When they tracked the movement of all the queens, the scientists noted the semen-addled queens were much likelier to get lost on their way back to the hive.

What's more, electrodes attached to the brains of queens suggested the bee semen had compromised their sensitivity to light.

It's hard to blame a doomed drone for wanting his lineage to carry on. But as callous as the queen may seem, she's only looking out for the colony. More mates means more semen — she can pack away as much as 6 million sperm, keeping them fresh for as long as seven years.

That adds up to around 1.7 million buzzing baby bees in her lifetime. And, some day, many of them will also get a chance to date a queen.

They, too, will do everything they can to make a lasting impression — and perhaps even be king for a day.