As we all know, our honeybees are having a terrible time, and while there are many factors to consider, the one that is most critical is the use of systemic pesticides. Systemic basically means that the active insect killing agent is within the plant itself. Therefore the flowers and the pollen are toxic to the bees.
Here's an excerpt of a great article that you should totally check out:
Of particular concern is a group of pesticides, chemically similar to nicotine, called neonicotinoids (neonics for short), and one in particular called clothianidin. Instead of being sprayed, neonics are used to treat seeds, so that they’re absorbed by the plant’s vascular system, and then end up attacking the central nervous systems of bees that come to collect pollen. Virtually all of today’s genetically engineered Bt corn is treated with neonics. The chemical industry alleges that bees don’t like to collect corn pollen, but new research shows that not only do bees indeed forage in corn, but they also have multiple other routes of exposure to neonics.
Here's the link to the rest of the article:
Let me know what you think!