Two groups want the Environmental Protection Agency to take action to protect bees from pesticides. Scientists think toxic substances play a role in bee deaths. New research at UC San Diego shows at least one type of pesticide may be a factor.
It's simple: We need bees to pollinate fruits, nuts and vegetables. Without them, no crops. But the bees started disappearing about four years ago.
Some commercial beekeepers in San Diego have already lost bees.
Researchers said it is possible a combination of mites, a new virus and pesticides are killing bees.
The Environmental Protection Agency evaluates the effects of pesticides on honey bees. But two groups want the EPA to include bumble bees and other crop-pollinating bee species.
UC San Diego researcher James Nieh agrees. He said continuing research points to pesticides.
"Right now we know through many prominent studies that globally there is a decline in overall pollinators," Nieh said. "Not only bees, but actually many other types of animals."
Nieh said his latest research shows a certain type of pesticide may reduce bees' interest in pollinating.
He and graduate student Daren Eiri are studying a specific neonicotinoid pesticide called imidacloprid and its effect on honeybees.
"What it does apparently when fed in very small dosages to bees it actually changes the bees' preference for the kinds of nectar that the bee would forage at," said Nieh.
Think of it as a change in the bees' sweet tooth.
"So that formerly bees that would accept more dilute, less sweet nectar, now will accept only very sweet nectar," Nieh said.
Nieh said most nectar in the environment is not super sweet. So, if bees reject natural nectar, it decreases the food coming into hives and may hurt the health of bee colonies.
"And it's possible that certain crops, and I believe almond flowers are one of them, that don't provide very sweet nectar and may not be perceived as very rewarding to the bees, those could be very disproportionately affected if the bees are not going to them because they're not satisfied with the sugar levels that are there," Nieh said.
The U.S. Department of Agriculture statistics show California produces 80 percent of the world's almonds.
"Almonds are 99 percent dependent upon the honey bees in February to pollinate their trees," said San Diego beekeeper Alan Mikolich. "Without the bees they get no crop."
The United States could lose $15 billion worth of crops, including California almonds, without bees to pollinate them.
