Theres been several things in the news over the years, showing an impact on bees. I remember talk of die-offs while growing up (before the mites became apparent), around the farming circles and bee keepers in the area I grew up in. Theres alot of variables that can affect a cycle, as some of the other posters have indicated.
The Purdue Bee Hive
It seems to be a combination of things occuring, pesticides, mites, and disease combining for a slow weakening and eventual death of a population. I wouldnt discount genetics and honey bee stocks/breeding being a partial factor.
What is overlooked is the native bee populations, which have shown a strong resistance to the mite/disease troubles that occur with the imported/domestic honey bees. Native bees do not produce the honey like domestics (euro/asian types) do. They dont have hives, (except the bumble bee) and they have different habitat needs.
Can Wild Bees Take Sting From Honeybee Decline?
Wild Bees
The Vanishing (part 3)
I know in my own yard / area during flowering, to wander around and look at all the types of bees and flys pollenating, is amazing. Add to that the many types of spiders that use the flowers as bait. Wow. There is just so much going on each day. Sometimes people dont take enough time wandering about looking at the little things surrounding those fruits/vegetables/flowers do they?