Pesticides may be shrinking bee population

WASHINGTON -- A common class of pesticide is causing problems for honeybees and bumblebees, species already in trouble, two studies suggest.

But the findings don't explain all the reasons behind a long-running bee decline, and other experts found one of the studies less than convincing.

The new research suggests the chemicals used in the pesticide, designed to attack the central nervous system of insects, reduces the weight and number of queens in bumblebee hives. The pesticides also cause honeybees to become disoriented and fail to return to their hives, the researchers concluded.

The two studies were published online yesterday in the journal Science.

Just last week activists filed a petition with more than a million signatures asking the government to ban the class of pesticides called neonicotinoids. The Environmental Protection Agency said it is re-evaluating the chemicals.

For more than a decade, pollinators of all types have been in decline, mostly because of habitat loss and perhaps some pesticide use. In the past five years, a new mysterious honeybee problem, colony collapse disorder, has further attacked hives. But over the last couple of years, that problem has been observed a bit less, said Jeff Pettis, lead bee researcher at the Department of Agriculture's lab in Beltsville, Md. -- AP