A bumblebee worker damaging a plant leaf. Photo: Hannier Pulido, De Moraes and Mescher Laboratories

For tens of millions of years, bees and flowers have evolved together. Flowering provides bees with food, and pollination gives plants a means of reproduction.

What's new: Bumblebee workers appear to be able to control that synchronized symbiosis by damaging the leaves of plants, according to a new study in the journal Science.

What they did: In a set of experiments in the lab and outside, Foteini Pashalidou, Harriet Lambert and their colleagues at ETH Zürich found pollen-starved B. terrestris bees bit holes in leaves, but well-fed bees did not.

  • In another experiment, they placed bees deprived of pollen in mesh cages with either tomato or black mustard plants. They found the speed of flowering increased (one month ahead of schedule for tomatoes and two weeks for black mustard plants).

It's unclear how bees learned this biting behavior and why plants respond by flowering.

  • The researchers compared bites by bees and those made with razors, and they found the damage from bees sped flowering up more than that done mechanically.
  • One possibility is that as bees bite the plant, they inject chemicals that speed up flowering.
"If so, scientists might realize a horticulturist’s dream by deciphering the molecular pathways through which flowering can be accelerated by a full month."
— Lars Chittka of Queen Mary University of London wrote in an accompanying paper

The big picture: Climate change is threatening the timing of the relationship between plants and bees, and it risks starving bees that are emerging early from hibernation.

  • Bee-inflicted damage may provide resilience to the important relationship between flowering and pollination that is under threat, the authors write.

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Sgt. Jonathan Mattingly, the Louisville officer who led the botched police raid that caused the death of Breonna Taylor, said the No. 1 thing he wishes he had done differently is either served a "no-knock" warrant or given five to 10 seconds before entering the apartment: "Breonna Taylor would be alive, 100 percent."

Driving the news: Mattingly, who spoke to ABC News and Louisville's Courier Journal for his public interview, was shot in the leg in the initial moments of the March 13 raid. Mattingly did not face any charges after Kentucky Attorney General Daniel Cameron said he and another officer were "justified" in returning fire to protect themselves against Taylor's boyfriend.

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The Justice Department fired the starter pistol on what's likely to be a years-long legal siege of Big Tech by the U.S. government when it filed a major antitrust suit Tuesday against Google.

The big picture: Once a generation, it seems, federal regulators decide to take on a dominant tech company. Two decades ago, Microsoft was the target; two decades before that, IBM.

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If the impasse between House Speaker Nancy Pelosi and the White House on a new stimulus deal is supposed to be a crisis, you wouldn't know it from the stock market, where prices continue to rise.

  • That's been in no small part because U.S. economic data has held up remarkably well in recent months thanks to the $2 trillion CARES Act and Americans' unusual ability to save during the crisis.