Honeybee hive collapse mystery rooted in hive size

I haven't seen work done on critical give size, so even though this doesn't address the decline of bees, it helps us understand what the critical point is where there will be collapse... "Scientists are working to understand a baffling but vitally important puzzle: What is causing the decline of honeybees? A new mathematical model demonstrates vulnerability of hives with too few bees. The model indicates that any or all suspected environmental factors, alone or in combination, could lead to hive collapse by destabilizing a hive's adult bee population."