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St Andrews University - Insecticides and brain damage



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Neonicotinoids are a class of neuro-active insecticides chemically similar to nicotine. In the 1980s Shell and in the 1990s Bayer started work on their development. The neonicotinoid family includes acetamiprid, clothianidin, imidacloprid, nitenpyram, nithiazine, thiacloprid and thiamethoxam, of which imidacloprid is the most widely used insecticide in the world.

In the late 2000s some neonicotinoids came under increasing scrutiny over their environmental impacts. The use of neonicotinoids was linked in a range of studies to adverse ecological effects, including honey-bee colony collapse and loss of birds due to a reduction in insect populations. Several countries restricted or banned the use of certain neonicotinoids.

In the U.S., neonicotinoids are currently used on about 95 percent of corn and canola crops; the majority of cotton, sorghum, and sugar beets; and about half of all soybeans. They are also used on the vast majority of fruit and vegetable crops, including apples, cherries, peaches, oranges, berries, leafy greens, tomatoes, and potatoes. Neonicotinoids are also applied to cereal grains, rice, nuts, and wine grapes.  Imidacloprid is effective against sucking insects, some chewing insects, soil insects and is also used to control fleas on domestic animals. It is possibly the most widely used insecticide, both within the neonicotinoids and in the worldwide market. It is also applied against soil, seed, timber and animal pests as well as foliar treatments for crops including: cereals, cotton, grain, legumes, potatoes, some fruits, rice, turf and vegetables. It has a long residual activity. Imidacloprid can be added to the water used to irrigate plants. Controlled release formulations of imidacloprid take 2–10 days to release 50% of imidacloprid in water.

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St Andrews University

Researchers buzzing about new finding

Friday 06 February 2015

Researchers buzzing about new finding

Researchers at the Universities of St Andrews and Dundee have found very strong evidence that low levels of neonicotinoid insecticides have adverse effects on bumblebee colonies.  The team, which involved Professor Steve Buckland of the School of Mathematics and Statistics at St Andrews, found that neonicotinoids caused both impairment of bumblebees’ brain cells and subsequent poor performance by bee colonies, with an estimated 55 per cent reduction in live bee numbers.

His colleague in Dundee, Dr Chris Connolly, has spent several years examining the risk from neonicotinoids and other commonly used classes of pesticides on both honeybees and bumblebees.

The new research demonstrates for the first time that the low levels of neonicotinoids found in the nectar and pollen of plants is sufficient to deliver neuroactive levels to their site of action, the bee brain.

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