Why some Italian winemakers don't want to use well-known pesticides? The reason is simple: they do kill pests but they also kill bees and without bees there's no wine. And no food for people, for that matter.
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Two studies have highlighted a negative impact on bees' ability to learn when exposed to a combination of pesticides used in agriculture. The researchers found that the pesticides, used at levels shown to occur in the wild, could interfere with the learning circuits in the bee's brain. They also found that bees exposed to combined pesticides were slower to learn or completely forgot important associations between floral scent and food rewards.
The University of Dundee's Christopher Connolly and his team investigated the impact on bees' brains of two common pesticides: neonicotinoid used on crops since 1994, and coumaphos that is used in honeybee hives to kill the Varroa mite, a parasitic mite that attacks the honey bee.
The intact bees' brains were exposed to pesticides in the lab at levels predicted to occur following exposure in the wild and brain activity was recorded. They found that both types of pesticide target the same area of the bee brain involved in learning, causing a loss of function. If both pesticides were used in combination, the effect was greater.
Geraldine Wright and Sally Williamson at Newcastle University found that combinations of these same pesticides affected learning and memory in bees. Their studies show that 30% of honeybees exposed to combinations of these pesticides for four days failed to learn or performed poorly in memory tests.That means that bees that cannot learn will not be able to find food and that has profound implications for honeybee colony survival.
That in turn has huge consequences: honeybees are responsible for fertilizing plants and that is a process essential for maintaining our food supply. So, it's simple: no bees, no food. Time to think a bit about that and find another way to fight against pests because we are in fact fighting against the key element in our food chain. ■
Residents in coastal North Carolina and Virginia braced for potential flooding after Tropical Storm Ophelia made landfall near a North Carolina barrier island on Saturday morning, bringing rain, damaging winds and dangerous surges of water.