Thread: Colony collapse disorder

Bug spray killin' the bees...

Insecticides linked to honeybee die-offs
WASHINGTON, March 15,`12 (UPI) -- Die-offs of honeybees critical for pollinating food crops -- part of so-called colony collapse disorder -- is linked to an insecticide, a U.S. journal reports.

Researchers from the University of Padua in Italy writing in the journal Environmental Science & Technology say the springtime die-offs have been linked to technology used to plant corn coated with insecticides. In some parts of Europe where farmers use the technology to plant seeds coated with so-called neonicotinoid insecticides, widespread deaths of honeybees have been reported since the introduction of the technique in the late 1990s, they said.

Such 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. Scientists said they suspected the bee die-offs might be due to particles of the insecticide made airborne by the pneumatic drilling machines used for planting that forcefully suck seeds in and expel a burst of air containing high concentrations of particles of the insecticide coating.

They found that honeybees that flew through the emission cloud of the seeding machines used in mid-March to May corn planting were dying. Future work on the problem should focus on a way to prevent the seeds from fragmenting inside the pneumatic drilling machines, the researchers said.

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One contributing factor to colony collapse disorder...

Pesticides hit queen bee numbers
29 March 2012 - Pesticides are not the whole problem, but some think they could be a significant one

Some of the world's most commonly used pesticides are killing bees by damaging their ability to navigate and reducing numbers of queens, research suggests. Scientific groups in the UK and France studied the effects of neonicotinoids, which are used in more than 100 nations on farm crops and in gardens. The UK team found the pesticides caused an 85% drop in queen production. Writing in the journal Science, the groups note that bee declines in many countries are reducing crop yields. In the UK alone, pollination is calculated to be worth about £430m to the national economy.

And the US is among countries where a succession of local populations has crashed, a syndrome known as Colony Collapse Disorder. Many causes have been suggested, including diseases, parasites, reduction in the range of flowers growing wild in the countryside, pesticides, or a combination of them all. The neonicotinoids investigated in the two Science papers are used on crops such as cereals, oilseed rape and sunflowers.

Often the chemical is applied to seeds before planting. As the plant grows, the pesticide is contained in every part of it, deterring insect pests such as aphids. But it also enters the pollen and nectar, which is how it can affect bees. Dave Goulson from the UK's University of Stirling and colleagues studied the impact of the neonicotinoid imidacloprid on bumblebees. They let bees from some colonies feed on pollen and sugar water containing levels of imidacloprid typically found in the wild, while others received a natural diet. Then they placed the colonies out in the field.

'Severely compromised'

After six weeks, colonies exposed to the pesticide were lighter than the others, suggesting that workers had brought back less food to the hive. But the most dramatic effect was on queen production. The naturally-fed hives produced around 14 queens each - those exposed to the pesticide, just two. "I wouldn't say this proves neonicotinoids are the sole cause of the problems bees face," said Dr Goulson, "but it does suggest they're likely to be one of the causes, and possibly a significant one. "The use of these pesticides is so widespread that most bee colonies in areas of arable farming are likely to be exposed to them, so there is potential for them to be playing a significant role in suppression of bee populations on a pretty staggering scale."

More http://www.bbc.co.uk/news/science-environment-17535769