In the media buzz about bee losses, a lot of proposals have been floated about how to replace natural pollinators, come the beepocalypse. Robotic bees seem like a fairly simple proposition; fly the robot around to flowers, collect pollen, transfer pollen, done. Just one problem: Some plants don't give it up that easily.

Pollen is plant sperm, and bees and plants have evolved a complex sexual surrogacy over their millions of years of evolution together. Some plants lure pollinators in with a nectar cocktail, and then dump pollen on them as a price for free drinks. Some have flower parts that are only accessible with a long tongue. And some plants require stimulation before they will release their load of pollen.

Buzz-pollinated flowers wait until a bee comes along and vibrates at just the right frequency, in just the right spot, and bang! Out comes the pollen in a spew. Potatoes, tomatoes, eggplants, and peppers; pumpkins, zucchinis, blueberries and cranberries: these food plants are examples of crops that require buzz pollination.

Original Video by Karl Ford, UMN.

When a bee sonicates, she basically dumps the clutch on her wings to put them in neutral, and revs up her wing muscles. This produces a vibrating vroom up to 400 Hz, or 24,000 vibrations per minute. It creates a distinct buzzy sound, which is sometimes interpreted as the bee being "angry." Nope, she's just working hard to convince the flower to expel its pollen.

Original Video by Karl Ford, UMN.

It seems a bit counterintuitive for a flower to evolve a pollen chastity belt that can only be opened by bees capable of vibrating at a specific frequency. If you need bees to serve as your sperm courier, why not just toss pollen around freely to everyone?

Restricting sperm to just specialized pollinators that can hit their Bee-spot encourages a kind of flower monogamy. Buzz pollinated flowers don't discharge all their pollen in a big gush; they only release about 20% of their total pollen in each burst. That encourages bees to make multiple visits to flowers of the same type. That means more cross-pollination, less inbreeding, and more fruit and seeds for the plant.

Honey bees are incapable of buzz pollination, which makes them ineffective pollinators. What we need is more native bumble bees and solitary bees. Many of these species co-evolved with the ancestors of our crop plants to specialize on just a few fruits and vegetables.

A Solution to the Pollination Problem Is at Hand

The best solution, of course, would be to preserve the bees we have. But we do already have a way to pollinate without bees. Tomatoes grown in greenhouses are walled off from their usual pollinators, so farmers developed a way to solve the no-bees problem. We don't need fancy mini-drones; we need robo-vibrators.

Vibrators are very effective bee-substitutes for plants that need buzz pollination. It's fairly detailed work though; in one trial it took 11.75 hours to pollinate 640 tomato plants with a vibrator, slightly over 1 minute per plant. The increase in fruit yield is usually well worth the time and effort, though.

Louisiana Agriculture , published by the Louisiana State University AgCenter.

Vibrators are sometimes used on crops that normally wind pollinate to increase their fruit set. In the words of the Date Palm and Tropical Fruits Research Institute of Iran: "The results are excellent and the pollen goes everywhere."

You can buy a plant vibrator for home use called an electric bee; it's cleverly designed to bring forth the pollen in a spurt. Some come with a handy plant-jizz collector, so you don't pull an Onan and spill your (future) seed on the ground.

Veggie Bee Patent Application US 2013/0305600 A1

The VeggieBee is adjustable for intensity; its range is 29,000-44,000 vibrations per minute, very similar to a bumble bee. As a comparison, a Hitachi Magic Wand, one of the most intense "personal massage" devices available, provides 6,000 vibrations per minute. I hope you now have more respect for just how much buzz a bumble bee can generate.

You can also choose to make your own; most electric toothbrushes have enough buzz to coax out pollen. Tuning forks also work. Or, you know, you could just duct-tape your ex-girlfriend's vibrator to a grill brush and use that.

This story has a happy ending; more and more farmers are learning to value and encourage native bees around their farms. You can take part in a citizen science project to help bumble bees, the best of the buzz pollinators. There is also a free book available as a download on bumble bee conservation, if you want to learn more.

De Luca and Marin. 2013. What's the ‘buzz’ about? The ecology and evolutionary significance of buzz-pollination. Current Opinion in Plant Biology 16(4). dx.doi.org/10.1016/j.pbi.2013.05.002

Floral sonication by bees: Mesosomal vibration by Bombus and Xylocopa, but not Apis (Hymenoptera: Apidae), ejects pollen from poricidal anthers.

Journal of the Kansas Entomological Society. Volume 76, Issue 2, April 2003, Pages 295-305