It's refreshing to see such care taken to avoid conflating correlation with causation. Even when faced with such a complex system, you can chip away at the mystery if you apply some discipline.

Although I am a little curious about some of the less-mainstream theories: "Other hypotheses were untestable at best, such as claims that the bees were being abducted by aliens." With our pride, we always _assumed_ the aliens would _naturally_ want to abduct us!