Mystery of why one third of bee populations vanish every year could be solved as scientists find link with corn insecticide

http://www.dailymail.co.uk/news/article-2116263/Mystery-populations-vanish-year-solved-scientists-link-corn-insecticide.html

By Daily Mail Reporter

PUBLISHED: 21:22 EST, 16 March 2012 | UPDATED: 23:48 EST, 16 March 2012

New research has found a link between the increase in the death of honeybees and insecticides used to coat corn seeds.

Since seed coating with neonicotinoid insecticides was introduced in the late 1990s, European beekeepers have reported severe colony losses in the period of corn sowing, according to an article in the journal Environmental Science & Technology.

Beekeepers from the US, where one-third of honeybee hives disappear each year, to China have also experienced mass deaths in recent years.

Research: A new study has found a link between the increase in the death of honeybees and insecticides used to coat corn seeds

But the reasons behind colony collapse disorder have remained relatively unexplained until now.

The study entitled ‘Assessment of the Environmental Exposure of Honeybees to Particulate Matter Containing Neonicotinoid Insecticides Coming from Corn Coated Seeds,’  says neonicotinoid insecticides ‘are among the most widely used in the world, popular because they kill insects by paralyzing nerves but have lower toxicity for other animals.’

But, when this particular kind of insecticide was used around the time of corn planting in spring, beekeepers immediately observed an increase in die-offs.

Scientists thought this might be due to particles of insecticide made airborne by the drilling machines used for planting, which suck the seeds in, and then spray them with insecticide to create a coating before they are planted in the ground.

History: Since seed coating with neonicotinoid insecticides was introduced in the late 1990s, European beekeepers have reported severe colony losses in the period of corn sowing

In an effort to make the pneumatic drilling method safer, the scientists tested different types of insecticide coatings and seeding methods.

They found, however, that all of the variations in seed coatings using neonicotinoid insecticides killed honeybees that flew through the emission cloud of the seeding machine.

According to the study, one machine modified with a deflector to send the insecticide-laced air downwards still caused the death of more than 200 bees foraging in the field.

‘Experimental results show that the environmental release of particles containing neonicotinoids can produce high exposure levels for bees, with lethal effects compatible with colony losses phenomena observed by beekeepers,’ the researchers, led by Andrea Tapparo from the University of Padua, in northern Italy, said.
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