Wow. I've been interested in this, but those two articles are rather useless. I agree with your assessment: tell the bees to stop using cell phones.

EM radiation might be an interesting lead, but certainly doesn't seem like it's time to say that it's the fault of cell phones. That's like saying if you impant a cell phone in my brain, and I die, it's because of cell phone radiation.

preaching to the choir, here, I know....

However, maybe they can follow this lead into the real culprit. Unusual magnetic fluctuations from the sun? Power lines? something...