Better than honey? Bees flock to sunlight-induced fluorescence.
Science sometimes finds a way of presenting valuable information when no one is looking.
Oregon State entomologist Sujaya Rao was conducting research on the “Pest Beetle” affecting many cranberry and blueberry fields when she was struck by an unusual occurrence in her pest traps. They were full of wild bees. But only the blue traps. Curious, Rao tested several different shades of blue pest traps. One particular shade of blue attracted scores of wild bees, while nearly identical blue traps attracted none. What did the bees see?
Rao, housed in the College of Agricultural Sciences Department of Crop and Soil Science, connected with Oksana Ostroverhova in the Physics Department to better understand the optical properties of bee traps. But Ostroverhova's expertise lies in electronic, optical and non-linear optical properties of organic materials; she was new to the study of “bee vision.” However, Ostroverhova’s skill in testing optical properties of materials was well-matched to Rao’s expertise in testing how formulas work in the field.
“I believe in interdisciplinary research,” said Ostroverhova. “If you bring expertise from multiple areas, that will bring innovation. I’m always on the lookout for opportunities like this. Whether working with optical properties or solar cells, it’s the same science, just a different application.”
Bees have ultraviolet, blue and green photoreceptors in their eyes to help them locate food in landscapes that continuously change. The researchers tested the visual response among multiple species of wild bees using a bee-attractive, fluorescent blue plastic trap as a model for analyzing visual cues in nature.
If successful, the impacts to the economy and agriculture would be tremendous. Bees perform about 80 percent of all pollination worldwide, which is essential to fruits, nuts and vegetables. The rapid decline of bee colonies around the world is well known—bees are dying from a variety of factors from pesticides, drought, habitat destruction, nutrition deficit, air pollution, global warming and more.
Although collaborating since 2008, Rao and Ostroverhova just published their findings that revealed the extraordinary bee attraction can be attributed exclusively to stimulation of the bee’s photoreceptor. Preliminary feedback has been overwhelmingly positive: reviewers called the discovery “highly innovative, high impact research” that promises significant advances in science for society.
Elated, the pair submitted funding proposals for $150,000 to NSF’s Small Business Technology Transfer Program and the U.S. Dept. of Agriculture’s Small Business Innovation Research program. Initial funding would enable the researchers to launch the next phase of their study: how to incorporate a blue dye into a formula that would stimulate the blue photoreceptor in bees, attracting them to fertile clover fields during periods of pollination. If funded, the research would commence in the spring.
Bound by limited resources and a desire to be good stewards of the environment, Rao and Ostroverhova will test their theories using a food-grade blue dye that’s fluorescent under sunlight and a low-impact substance. In contrast, a blue laser would require supplying substantial power to remote clover fields.
Another surprise for Rao and Ostroverhova: they found species of wild bees that were not known to Oregon. Proving once again that serendipity is one of science's strongest allies.