Researchers link insecticides to bee colony collapse

Scientists at Purdue University think they have identified one of the causes of honeybee death close to agricultural fields: insecticides. Science Daily reports analyses of bees found dead at hives from several apiaries in Indiana show the presence of neonicotinoid insecticides commonly used to coat corn and soybean seeds before planting. High concentrations of the insecticide were found in farm machinery talc exhaust. This is not the first study to imply a link between colony collapse disorder and insecticide use, but is the first to find conclusive evidence. (Photo: Junji Takano, Pyro-Energen)

Researcher Christian Krupke said insecticides, which are highly toxic to bees, were found in each sample of dead bees collected over a two-year period. He said live bees at collection sites were exhibiting odd behavior, including tremors, uncoordinated movement and convulsions, which are all signs of insecticide poisoning. Krupke said the corn pollen bees were taking to hives was contaminated with neonicotinoids at levels high enough to kill bees if "sufficiently consumed," but talc exhaust from machinery contained levels up to about 700,000 times the lethal dose for bees.

Researcher Greg Hunt said there is no single cause of colony collapse disorder, which is devastating bee populations. Scientists believe other factors, including parasitic mites, habitat destruction, lack of food sources and poor quality food, could all contribute.