I'm not sure I captured this fairly above. There seem to be three primary drivers to the collapse:
- Parasites from Australian bees (impacting them like smallpox did the indians when europeans came to north america)
- Pesticides which impact the nervous system and cause difficulty learning/remembering where the hive is
- Malnutrition (since the bees are feeding on single crops for weeks at a time, instead of many different plants and flowers, they are malnourished, and are experiencing something akin to scurvy)
All of these factors are making them more vulnerable to disease and illness. These diseases and illnesses were never such a factor in the past, but when afflicting bees all at the same time, their effects are cumulative.
