Mr. Rexroad said the cause of the sudden loss of bees is not clear. The number of honey bees already had fallen before the colony collapse disorder began.

• 雷洛先生说，引起蜜蜂忽然失踪的原因尚没明确，但很多蜜蜂在正常的“群体崩溃紊乱”之前就失踪了。