A comprehensive federal government study published in the US says the devastation of American honeybee colonies is the result of a complex stew of factors, including pesticides, parasites, poor nutrition and a lack of genetic diversity.
The report has been published in the same week as European officials took steps toward banning a class of pesticides known as neonicotinoids, derived from nicotine, that they consider a critical factor in the mass deaths of bees there.
Agcarm, the New Zealand organisation which represents manufacturers and distributors of crop protection and animal health products, challenged the evidence in support of the European Union curbs.
Officials in the United States Department of Agriculture, the Environmental Protection Agency and others involved in the bee study agreed there was not enough evidence to support a ban on one group of pesticides, and that the costs of such action might exceed the benefits.
According to the New York Times (here), the US report does not place more weight on one factor over another.
It recommends a range of actions and further research.
Millions of bees have been dying since 2006 in a phenomenon known as colony collapse disorder. The cause or causes have been the subject of much study and speculation.
But what should be done?
“At E.P.A. we let science drive the outcome of decision making,” said Jim Jones, the agency’s acting assistant administrator for chemical safety and pollution prevention. “There are non-trivial costs to society if we get this wrong. There are meaningful benefits from these pesticides to farmers and to consumers, as well as for affordable food.”
May R. Berenbaum, head of the department of entomology at the University of Illinois at Urbana-Champaign and a participant in the study, said that examination of dead bees had found residues of more than 100 chemicals, insecticides and pesticides, including some used to control parasites in bee hives.
Like Mr. Jones, she rejected the idea of an immediate ban on the use of neonicotinoids or any other single pesticide.
“It’s not a simple matter of just removing pesticides,” she said in a conference call for reporters Thursday. “It is difficult to predict the effect of removing one of 100 different contaminants.”
“There is no quick fix,” she said. “Patching one hole in a boat that leaks everywhere is not going to keep it from sinking.”
The parasitic mite Varroa destructor, which has infested NZ beehives only in recent years, is one of the most fatal afflictions in bee colonies and is thought to be responsible for numerous die-offs.
Another factor is the planting of vast areas in a single crop such as corn, limiting the forage supplies for bees.
Zac Browning, a fourth-generation commercial beekeeper who operates more than 20,000 hives for honey production and pollination in California, Idaho and North Dakota, said the solution to the bee crisis will require a broad approach and many players.
He said that the supply of bees is falling short of the need, citing difficulty rounding up enough bees to pollinate the winter almond crop in California and blueberry bushes in Maine this spring.
“We’re on the brink,” he said. “I don’t know if we’ve crossed that threshold yet, but we’re getting there fast.”
NZ Federated Farmers this week said it believes enough research will be available within two years to scientifically inform decision-making in this country on the future use of a class of pesticides restricted in Europe to protect bees.
Federated Farmers said New Zealand’s less restrictive but cautious approach than Europe was appropriate, until a scientific consensus was reached.
Vice-president Dr William Rolleston said concerns had been raised before that the neonicotinoids could harm bees, and as result seed coating was regularly monitored in New Zealand to avoid the potential for dust production during sowing. The neonicotinoid family was mainly used on crops and as a seed treatment in New Zealand.
“While you could say New Zealand is taking a less restrictive approach, in our view, we will be better informed by research being undertaken in Europe. (This is) something we expect within the next two years, when the EU reviews the partial restriction it is imposing.”
Rolleston said bee health was central to pastoral agriculture, and horticultural industries and correct applications for all insecticides and foliage sprays was needed.