Nicotinyl pesticides, containing clothianidin, thiametoxam and imidacloprid, used to coat plant seeds, are released into the lymph as a permanent insecticide inside the plant. But after just sucking dew from maize leaves that absorbed neonicotinoids, disoriented bees can't find their way to the apiary. Massive numbers of bees get lost and die.
Neonicotinoid use has been strictly limited in France since the 1990s, when neonicotinoids were implicated in a mass die-off of the bee population. It is believed by some to account for worker bees' neglecting to provide food for eggs and larvae, and for a breakdown of the bees' navigational abilities, possibly leading to what has become generally known as Colony Collapse Disorder.