Pollinating flowers with drones
In a beehive, the female worker bees are the ones that fly out to gather pollen and nectar—transferring pollen from one flower to another in the process—while the main job of the male drones is to romance the queen. But in Eijiro Miyako’s lab at the Nanomaterials Research Institute in Japan, another kind of drone is being readied for fieldwork. By adding sticky fibers to the underside of a flying robot, Miyako and his group have shown that such drones can act as artificial pollinators (Chem 2017, DOI: 10.1016/j.chempr.2017.01.008).
A decade ago, Miyako developed an ionic-liquid gel for use in batteries and other electrochemical applications. But it didn’t perform better than conventional ionic-liquid gels, so he put it away and forgot about it. When he found it again two years ago, he accidentally dropped the material on the floor and noticed how well it picked up dust. “TV programs about the pollination crisis, honeybee decline, and cutting-edge robotics also emotionally motivated me,” he tells Newscripts. He realized that his gel could find a new life as a semipermanent adhesive, perfect for picking up and transferring pollen.
Miyako and his colleagues coated horsehair fibers from a paintbrush with the gel and attached a patch of the fibers to a palm-size, wirelessly controllable drone. Then they ran tests on lilies, flying the robot to one flower’s stamen to pick up pollen, then maneuvering to another flower’s pistil to brush on the grains. Using fluorescent microscopy, they confirmed that the pollen did indeed get transferred. The next day, they even saw the formation of fibrous pollen tubes, indicating successful fertilization.
Honeybees are vital to agriculture as pollinators; could drones provide an alternative? Miyako admits that with the cost of commercial drones at $100 each and the strong operator skills required, it would be costly to do wide-scale pollination this way. “It was very hard work to control the robotic pollinators to precisely hit onto the target sites,” he says. However, he’s optimistic that the cost of drones will come down and artificial intelligence could make the process more efficient. For the time being, though, bees probably don’t need to worry about robots taking their jobs.
A honeybee whoop-de-do
Robotic drones also can’t compete with honeybees when it comes to modes of communication. Researchers at Nottingham Trent University have now deciphered one bit of the complex language of these social insects. They’ve found that bees produce a small vibrational pulse, which sounds like a “whoop” to human ears, when they’re startled. The sound had been observed before but had been interpreted as a begging call or a stop signal. The Nottingham researchers found that bees produced the sound in many circumstances, often when they bumped into each other (PLOS One 2017, DOI: 10.1371/journal.pone.0171162). In a crowded hive, it probably doesn’t hurt to be polite.