Researchers around the world have reported that bees' navigational abilities are hampered and their immune systems break down after exposure. Combine neonicotinoid exposure with treating bees for parasitic mites and they can't remember associations between flower scents and food rewards.
The article states that from 2000 to 2011, total U.S. honey production fell one-third from 221 million to 148 million pounds while the three most common neonicotinoid pesticides (imidacloprid, thiamethoxan and clothianidin) grew from about 280,000 pounds to more than 4.5 million pounds. In frustration, some commercial beekeepers are no longer renting their hives out to farmers.
Thanks to author Patrick J.Kiger for his excellent research.