Pesticides Turn Bumblebees Into Poor Pollinators (acs.org)
MTorrice writes about a new study that suggests neonicotinoids, one of the most widely used insecticides in the world, turn bumblebees into poor pollinators, leading to lower yields of apples and other plants. Chemical & Engineering News reports: "Neonicotinoid pesticides have been blamed for declines in bee populations worldwide. The chemicals don't kill bees, instead neonicotinoids impair the insects' abilities to learn, navigate, forage for nectar, and reproduce, according to studies published over the past several years. Now, researchers report that bees exposed to the pesticides also become less effective pollinators for crops. The study is the first to demonstrate that neonicotinoids can decrease the quality of a food crop by affecting bee pollination. About 30% of our food comes from crops, including fruits, nuts, seeds, and oils, that depend on insect pollinators, according to Dara A. Stanley of Royal Holloway, University of London, who led the new study. 'Basically,' she says, 'you can't have a balanced diet without insect pollination.'"
Because neonicotinoids are among the safest overall pesticides that have ever been developed. They very effectively target insects, but have very minor effects on mammals. The LD50 of Safari is over 2000 mg/kg of body weight in rats. They're rated category III by the EPA, which means 'slightly toxic and/or slightly irritating.'
The big problem is with bees. Neonics are supposedly 150X more lethal to bees than to any other insect genera.
The EU has already banned neonics (possibly because population density is higher and bees may be more shared than in the US); the US is dragging their feet.
John