No Correlation Between Neonicotinoids and Hive Losses

CLAIM: Outbreaks of CCD since the introduction of neonicotinoids indicate that these pesticides are a key cause of CCD.

REALITY: There is no correlation between neonicotinoids and hive losses related to CCD or other causes.

Environmentalists and many government officials have singled out crop protection chemicals called neonicotinoids as the potential cause of CCD. For example, Greenpeace claims that “neonicotinoids might just be the prime culprit in the honeybee plague known as Colony Collapse Disorder (CCD)” based largely on a single, flawed Harvard University study. As a result of such claims, the European Union has even placed a temporary ban on the use of these chemicals based on largely speculative science about their possible link to CCD. But the data do not support such definitive claims or actions.

Neonicotinoids are a class of pesticide products that enhance a plant’s ability to fight off pests. Specific chemicals include acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam. They are “systemic” treatments because they become part of the plant, making it unattractive to pests that chew on the plants. Neonicotinoids may be sprayed on the plants, applied on the ground near the plant’s roots, or applied to seeds. But the overwhelming majority of uses are applications in which seeds are treated with the pesticide before planting, a practice that avoids broad environmental exposure.

Systemic pesticides have the benefit of limited environmental impact because little enters into the environment, especially when seeds are treated. However, minuscule amounts of the chemicals may appear in the pollen and nectar of these plants, and the question then is whether these levels have an impact on honeybees and other non-target insects.

If neonicotinoids were a cause of CCD, we would expect to see at least some correlation between their use and CCD, but no such pattern has been observed since their introduction in the 1990s. France banned Imidacloprid in 1999 and, along with Germany, banned clothianidin in 2008, yet those bans did not prevent the emergence of CCD in both of those nations.

In Europe during 2013-2014, hives survived well in many areas where neonicotinoids were used. See the map for this distribution of losses from the recent EU survey on hive survival. Ironically, Greek beekeepers complained in 2013 that the chemicals were wreaking havoc, yet Greece actually had a lower than acceptable hive loss that year. This situation underscores the fact that some beekeepers and environmental activists are jumping the gun, blaming neonicotinoids for colony collapse disorder even in regions and years where evidence of a problem is not at all clear.

Conversely, in many places where these chemicals are used widely, such as in Australia, CCD is not a problem. A 2014 Australian government report states: “Australian honeybee populations are not in decline, despite the increased use of this group of insecticides in agriculture and horticulture since the mid-1990s.” Similarly, in Canada, one beekeeper explains:

[T]here are colonies in Ontario and Quebec that are exposed to neonics on both corn and soy, with zero problems. And look at Western Canada. On the Prairies, 70 percent of Canada’s colonies forage canola without issue. We are even exposed to corn and soy, and except for four beekeepers in Manitoba in 2013, there have been no issues there either.


Copy Protected by Chetan's WP-Copyprotect.