Yikes!  We were looking at our beehive the other day and there were several, like 30 bees walking around with deformed wings.  It was sad, really.  The wings were either short or just twigs, and the bees were just wandering around looking sad that they were kicked out of the hive, but had nowhere else to go.  We rushed to the internet and found that it is probably a virus called DMV that is spread via the "Varroa mite".  Those pesky mites.  I hate them.  We purchased a 21-day treatment of Formic acid that comes in the form of a "pad" that goes on the top of the frames.  Hopefully in 3 weeks they'll be all gone and our bees will by flying again.