As bee populations dwindle, drone pollinators’ use studied

Remote-controlled device could play key role in crops.

One day, gardeners might not just hear the buzz of bees among their flowers, but the whirr of robots, too. Scientists in Japan say they’ve managed to turn an unassuming drone into a remote-controlled pollinator by attaching horsehairs coated with a special, sticky gel to its underbelly.

The system, described in the journal Chem, is nowhere near ready to be sent to agricultural fields, but it could help pave the way to developing automated pollination techniques at a time when bee colonies are suffering precipitous declines.

In flowering plants, sex often involves a threesome. Flowers looking to get the pollen from their male parts into another bloom’s female parts need an envoy to carry it from one to the other. Those third players are animals known as pollinators — a diverse group of critters that includes bees, butterflies, birds and bats, among others.

Animal pollinators are needed for the reproduction of 90 percent of flowering plants and one-third of human food crops, according to the U.S. Department of Agriculture’s Natural Resources Conservation Service. Chief among those are bees — but many bee populations in the United States have been in steep decline in recent decades, likely due to a combination of factors, including agricultural chemicals, invasive species and climate change.

Just last month, the rusty patched bumblebee became the first wild bee in the United States to be listed as an endangered species, although the Trump administration put a halt on that designation.

Thus, the decline of bees isn’t just worrisome because it could disrupt ecosystems, but also because it could disrupt agriculture and the economy. People have been trying to come up with replacement techniques, the study authors say, but none of them are especially effective yet — and some might do more harm than good.

“One pollination technique requires the physical transfer of pollen with an artist’s brush or cotton swab from male to female flowers,” the authors wrote. “Unfortunately, this requires much time and effort. Another approach uses a spray machine, such as a gun barrel and pneumatic ejector. However, this machine pollination has a low pollination success rate because it is likely to cause severe denaturing of pollens and flower pistils as a result of strong mechanical contact as the pollens bursts out of the machine.”

Scientists have thought about using drones, but scientists haven’t figured out how to make free-flying robot insects that can rely on their own power source without being attached to a wire.

“It’s very tough work,” said senior author Eijiro Miyako, a chemist at the National Institute of Advanced Industrial Science and Technology in Japan.

Miyako’s particular contribution to the field involves a gel, one he’d considered a mistake 10 years before.