An insecticide is suspected of causing a colony collapse disorder that has killed millions of honeybees worldwide and up to half of the 2.5 million colonies in the United States. The chief suspect, say many scientists, is imidacloprid, the most commonly used insecticide on the planet. The potent chemical can be sprayed on plants or *coated on seeds*, which then release the insecticide through the plants as they grow.

Research has shown that in sublethal doses imidacloprid and other neonicotinoids can impair honeybees' memory and learning, as well as their motor activity and navigation. Recent studies have reported "anomalous flying behavior'' in imidacloprid-treated bees, in which the workaholic insects simply fall to the grass or appear unable to fly toward the hive. Mark Longstroth, Michigan State University Extension's district educator for fruit in southwestern Michigan. Longstroth hasn't reviewed data on how imidacloprid is suspected to affect the honeybees, but he said implicating the chemical as the colony collapse culprit sounds plausible.

Some U.S. entomologists who recently have been analyzing dead bees have found a remarkably high number of viruses and fungal diseases in the carcasses, leading them to suspect there may be other culprits besides neonicotinoids. "When neonicotinoids are used on termites, they can't remember how to get home, they stop eating, and then the fungus takes over and kills them. That's one of the ways imidacloprid works on termites -- it makes them vulnerable to other natural organisms. So if you look at what's happening to honeybees, that's pretty scary.''
(GM Watch, 25/05/2007)