Researchers hope dye will attract bumblebees

CORVALLIS, Ore. – Oregon State University researchers hope that a fluorescent dye can attract more native bumblebees to farm fields to replace declining honeybees and boost the numbers of an insect essential to agriculture.

Bumblebees see in the ultraviolet spectrum, just beyond the light visible to humans.

Oregon State entomologist Sujaya Rao and other researchers learned recently that native bumblebees – which have nearly disappeared since the 1990s – are attracted to the blue fluorescent dye.

“Something about that blue is acting like a magnet,” Rao said.

The discovery, made last summer, could help boost bumblebee numbers and enable local farmers to rely more on the native insects as pollinators.

Honeybees are typically used in agriculture. But that species of bee is dying off because of a mysterious ailment known as colony collapse disorder, and the price of remaining honeybee hives is skyrocketing.

Increasing the bumblebee population might mitigate some of the impacts for the agricultural industry.

Rao said one way to do that is to attract the insects to flowering crops, which will result in more food for hives and more eggs laid by queens.

The fluorescent blue dye could lure bumblebees to the right areas at the right time of the year.

Honeybees, which have been domesticated, aren’t attracted to the fluorescent blue traps.

The Willamette Valley’s native bumblebee, which used to be the dominant native bee species, has nearly disappeared since the 1990s.

In 2006, three of the bumblebees were trapped and spotted for the first time in years in Oregon. In 2007, three more were caught, out of thousands that make their way into traps. None have been caught so far this year.

Planting more flowers also could increase the local bumblebee population.

“All year long, we need lots of flowers,” Rao said.