Pesticides Threaten Birds and Bees Alike, Study Says

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Courtesy of Phys.org:

Neurotoxic pesticides blamed for the world’s bee collapse are also harming butterflies, worms, fish and birds, said a scientific review that called Tuesday for tighter regulation to curb their use.

Analysing two decades of reports on the topic, an international panel of 29 scientists found there was “clear evidence of harm” from use of two pesticide types, neonicotinoids and fipronil.

And the evidence was “sufficient to trigger regulatory action”.

“We are witnessing a threat to the productivity of our natural and farmed environment,” said Jean-Marc Bonmatin of France’s National Centre for Scientific Research, co-author of the report entitled the Worldwide Integrated Assessment.

Far from protecting food production, these nerve-targeting insecticides known as neonics were “imperilling the pollinators, habitat engineers and natural pest controllers at the heart of a functioning ecosystem.”

The four-year assessment was carried out by The Task Force on Systemic Pesticides, which advises the International Union for Conservation of Nature, the world’s watchdog on species loss.

Neonics are widely used insecticides whose effects can be instant and lethal, or chronic. Exposure can impair smell and memory in some species, curb procreation, reduce foraging, cause flight difficulties and increase disease susceptibility.

Used for insect pest management in farming, but also in pet flea control, they have been fingered in the recent decline in bees—crucial pollinators of human food crops—in Europe, the Americas and Asia.

The latest study says these pesticides, absorbed by plants, are also harming other insect pollinators, fish and birds as they leach into soil and water.

The most affected species were terrestrial invertebrates such as earthworms, which are crucial soil-enrichers, said a press statement. Continue reading

Honeybees abandoning hives and dying due to insecticide use, research finds

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Scientists found bees from six of the 12 neonicotinoid-treated colonies had left their hives and died. Photograph: Rex Features

Courtesy of Damian Carrington @ The Guardian:

The mysterious vanishing of honeybees from hives can be directly linked to insectcide use, according to new research from Harvard University. The scientists showed that exposure to two neonicotinoids, the world’s most widely used class of insecticide, lead to half the colonies studied dying, while none of the untreated colonies saw their bees disappear.

“We demonstrated that neonicotinoids are highly likely to be responsible for triggering ‘colony collapse disorder’ in honeybee hives that were healthy prior to the arrival of winter,” said Chensheng Lu, an expert on environmental exposure biology at Harvard School of Public Health and who led the work.

The loss of honeybees in many countries in the last decade has caused widespread concern because about three-quarters of the world’s food crops require pollination. The decline has been linked to loss of habitat, disease and pesticide use. In December 2013, the European Union banned the use of three neonicotinoids for two years.

In the new Harvard study, published in the Bulletin of Insectology, the scientists studied the health of 18 bee colonies in three locations in central Massachusetts from October 2012 till April 2013. At each location, two colonies were treated with realistic doses of imidacloprid, two with clothianidin, and two were untreated control hives.

“Bees from six of the 12 neonicotinoid-treated colonies had abandoned their hives and were eventually dead with symptoms resembling CCD,” the team wrote. “However, we observed a complete opposite phenomenon in the control colonies.” Only one control colony was lost, the result of infection by the parasitic fungus Nosema and in this case the dead bees remained in the hive.

Previously, scientists had suggested that neonicotinoids can lead to CCD by damaging the immune systems of bees, making them more vulnerable to parasites and disease. However, the new research undermines this theory by finding that all the colonies had near-identical levels of pathogen infestation. Continue reading