It looks like there are still more studies needed if we really want to understand what is going on here.
The treated bees were about two to three times more likely to die while away from their nests, and the researchers said this was probably because the pesticide interfered with the bees' homing systems, so they couldn't find their way home.
That seems like quite the leap in logic, but I don't have the actual study in front of me. That pesticide harms bees sounds like a REALLY obvious conclusion, I kinda like bees and what they do for us.
"It takes all sorts of in & out-door schooling to get adapted to my kind of fooling" - R. Frost