Deaths of bees over the past couple of years that have been blamed on mites or poor management might actually have been from the mystery ailment which is striking down millions of bees now.

Some beekeepers believe they might have had this for three or four years.

The mystery ailment has been called Fall Dwindle Disease by some, others are referring to it as Colony Collapse Disorder (CCD). The essential point is that in 24 US states bees are dying.

Scientists at Penn State, the University of Montana and the US Department of Agriculture are among the quickly growing group of researchers and industry officials trying to solve the mystery.

CCD is the latest, and most serious, die-off of honey bee colonies across the US. It is characterized by, sudden colony death with a lack of adult bees in front of the dead-outs. Honey and bee bread are usually present and there is often evidence of recent brood rearing.

A recent analysis of dissected bees turned up an alarmingly high number of foreign fungi, bacteria and other organisms and weakened immune systems.

Researchers are also looking into the effect pesticides might be having on bees.

Among the clues being assembled by researchers:

* Although the bodies of dead bees often are littered around a hive, sometimes carried out of the hive by worker bees, no bee remains are typically found around colonies struck by the mystery ailment. Scientists assume these bees have flown away from the hive before dying.

* From the outside, a stricken colony may appear normal, with bees leaving and entering. But when beekeepers look inside the hive box, they find few mature bees taking care of the younger, developing bees.

* Normally, a weakened bee colony would be immediately overrun by bees from other colonies or by pests going after the hive's honey. That's not the case with the stricken colonies, which might not be touched for at least two weeks.