Legion Troll
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Many species of wild bees, butterflies and other critters that pollinate plants are shrinking toward extinction, and the world needs to do something about it before our food supply suffers, a new United Nations scientific report warns.
The 20,000 or so species of pollinators are key to hundreds of billions of dollars' worth of crops each year — from fruits and vegetables to coffee and chocolate. Yet 2 out of 5 species of invertebrate pollinators, such as bees and butterflies, are on the path toward extinction, said the first-of-its-kind report. Pollinators with backbones, such as hummingbirds and bats, are only slightly better off, with 1 in 6 species facing extinction.
And it's not just honeybees. In some aspects they're doing better than many of their wild counterparts, like the bumblebee, despite dramatic long-term declines in the United States and a mysterious disorder that has waned.
The report doesn't point to a single villain. Among the culprits: the way farming has changed so there's not enough diversity and wild flowers for pollinators to use as food; pesticide use, including a controversial one, neonicotinoid, that attacks the nervous system; habitat loss; disease, parasites and pathogens.
The report,which draws from many scientific studies, is the result of more than two years of work by scientists across the globe.
"The variety and multiplicity of threats to pollinators and pollination generate risks to people and livelihoods," the report stated. "These risks are largely driven by changes in land cover and agricultural management systems, including pesticide use."
One of the biggest problems, especially in the United States, is that giant swaths of farmland are devoted to just one crop, and wildflowers are disappearing.
There are both general and specific problems with some pesticide use, according to the report.
"Pesticides, particularly insecticides, have been demonstrated to have a broad range of lethal and sub-lethal effects on pollinators in controlled experimental conditions," the report said. More study is needed on the effects on pollinators in the wild. Herbicides kill off weeds, which are useful for wild pollinators, the report added.
The story of honeybees is a bit mixed. Globally over the last 50 years, the number of managed honeybee hives — ones where humans keep them either as a hobbyists or as professional pollinators — has increased, but it has dropped in North America and Europe, where there is the most data, the report said.
The number of managed hives in the United States was 5.5 million in 1961 and dropped to a low of 2.5 million in 2012, when colony collapse disorder was causing increased worries. The number of hives is now back up slightly, to 2.7 million.
http://mashable.com/2016/02/27/bees-butterflies-extinct-world-food-crops-un/#zjrlRz3c9EqS