Feb. 7 (Bloomberg) -- A malady that has killed billions of bees since 2006, threatening about $15 billion in pollinated crops, is devastating hives again, according to the U.S. Department of Agriculture's top honeybee researcher.

The effects of the renewed onset of Colony Collapse Disorder won't become apparent until month's end, when California almond growers begin to assess the quality of crop pollination, said Jeffery Pettis, research leader of the USDA's bee laboratory in Beltsville, Maryland. Tests of bee colonies are showing a nationwide recurrence of the disorder, he said.

``We're still losing a great number of bees, and we still don't know why,'' Pettis said yesterday in a telephone interview. ``We're still trying to find patterns.''

The disorder, characterized by mass disappearances or deaths of bees with devastated immune systems, affected about a quarter of all U.S. hive keepers in 2006 and 2007.

A virus that causes bee paralysis was identified as a potential contributor to hive collapse in September. Pesticides and the way the insects are handled also are being studied for their possible roles.

Left unchecked, honeybee losses may affect the availability and price of crops such as almonds, the USDA has said. A bee shortage may harm production of other pollinated crops such as blueberries and pumpkins, lowering profits at companies from Dole Food Co., the world's largest fresh-produce seller, to Hershey Co., maker of Almond Joy candy bars, and Blue Diamond Growers, the world's largest tree-nut processing and marketing company.

Imported Bees

Almonds were the ninth-biggest U.S. crop in value in 2006 at about $2 billion. The trees bearing the nuts require the services of most domestic commercial hives, as beekeepers truck their colonies around the country for growers. Farmers have also imported bees from Australia since 2005 to replenish supplies.

Anecdotal reports from growers indicate sufficient numbers of bees this year, said Marsha Venable, spokeswoman for the Almond Board of California in Modesto. The USDA's first report on this year's almond crop is set for release in May.

The effects of the malady may not be as severe this year as last because beekeepers are taking better care of their insects to maintain colony health, said Jerry Bromenshenk, chief executive officer of Bee Alert Technology Inc. in Missoula, Montana. The company identified the bee disorder in 35 states and one Canadian province last year.

Arizona Affected

Still, the disorder appears to be widespread. Bromenshenk, who also studies bees as a professor at the University of Montana, said he's received reports of the condition appearing in Arizona, a state not identified in his survey last year. Some beekeepers are less hesitant to talk about hive loss this year because of last year's intense media attention to the malady.

``It's hard to get a handle on how severe it is,'' he said. ``Our general impression is that the same states are getting hit and the severity levels are similar as last year, but it varies from beekeeper to beekeeper. Ones who were hit hard last year aren't having problems, and some who got through it before are seeing heavy losses this year.''

To contact the reporter on this story: Alan Bjerga in Washington at abjerga@bloomberg.net.

Last Updated: February 7, 2008 10:08 EST