In the survey, a hive loss was attributed to colony collapse if varroa or other mites were ruled out as a cause; few
dead bees were
found in a hive, a sign that they fled; a queen
bee and food reserves were both seemingly normal pre-collapse; and food reserves were left alone after fleeing.
In fact, another study published earlier this year in PLoS ONE,
found that
dead bees in Indiana, which had perished from Colony Collapse Disorder, had several different neonicotinoid pesticides in their systems.