Thirty-six percent of the country's commercial bee colonies have been lost this year. That's a record decline — and nobody knows why the bees are disappearing. The collapse of the commercial bee industry was the subject of a congressional hearing Thursday, as farmers, bee keepers and food producers implored Congress to spend more money on research into the case of the disappearing bees.Bees started disappearing in 2006. Last year there was a 31 percent decline in commercial bee colonies. At the hearing Thursday both Haagen-Dazs, the ice cream maker, and North Carolina's Burt's Bees asked Congress for help in discovering the malady that affects the nation's bees. "Pollinators are an essential part of our business," Haagen-Dazs brand manager Katty Pien said.The Farm Bill (passed over a presidential veto) authorizes spending on bee research but sets aside no specific money for the work.