Landmark report shows clear link between neonicotinoids and mass bee deaths

Insecticide could be causing damage to many other species and habitats as well

By Kundan Pandey
Published: Wednesday 25 June 2014


A new global study has linked the mass deaths of pollinating insects like bees with a group of pesticides and calls for their phase out or at least significant reduction.

The “Worldwide Integrated Assessment” carried out by a group of scientists says neonicotinoid insecticides and fipronil harm invertebrates. It reviewed 800 studies covering birds, animals, soil, water and bees and concluded that the pesticides pose a major threat to a wide range of invertebrate species in soil, including earthworms. Neonicotinoids were introduced in the early 1990s as replacement to older, more damaging chemicals.

The analysis published in Environment Science and Pollution Research (ESPR) included all available literature, and found that there is clear evidence of harm to bees.

Authors of the analysis, David Gibbons, associated with RSPB Centre of Conservation Science, UK, Christy Morrissey from department of Biology, University of Saskatchewan, Canada and Pierre Mineau from Pierre Mineau Consulting, Canada, concluded that neonicotinoid and fipronil insecticides can exert their impact on vertebrates either directly, through their overt toxicity, or indirectly, for example, by reducing their food supply.

The direct impact may take place through ingestion of the formulated product like bird eating seeds coated with insecticides or through uptake via skin following a spray. They affect organisms indirectly also. For example, birds may be affected because of reduction of their insect preys. The insecticides may also be harming the bees by weakening their immune system and making them prone to infectious diseases.
The species most affected by the insecticides, says the study, are terrestrial invertebrates such as earthworms which are exposed at high levels of the toxins through soil, plants and water.  The next most affected group is insect pollinators such as bees and butterflies which are exposed to high contamination through air and plants and medium exposure levels through water, according to the analysis.

Call for ban
Following the assessment, the Bee Coalition has urged UK government to take the report into account during the upcoming National Pollinator Strategy for England, expected in autumn 2014.

Vanessa Amaral-Rogers of Buglife, a member of the Bee Coalition and one of the scientists behind the report, said, “The evidence is clear that neonicotinoids are harming our pollinating insects and could be causing damage to many other species and habitats. Regulators must take a much more precautionary approach to pesticide authorizations.”

Another Bee Coalition member, Paul de Zylva  said that the widespread use of neonicotinoid seed treatments is not compatible with sustainable farming.  “Pesticides should be used only when they are really needed, not as an ‘insurance’ against possible pest damage.  We need to see a wholesale shift to more bee-friendly ways of farming,” he said.

The Bee Coalition formed in 2012 when the UK’s main environmental groups joined forces to call for a ban on neonicotinoid pesticides that are toxic to bees and pollinators.

Research: Multiple routes of pesticide exposure for honey bees living near agricultural fields

Feature: Pollinators – key for agro biodiversity conservation

Report: Global honey bee colony disorders and other threats to insect pollinators

Research: Iridovirus and Microsporidian linked to honey bee colony decline

Research: Sub-lethal effects of pesticide residues in brood comb on worker honey bee (Apis mellifera) development and longevity

Research: Interactions between Nosema microspores and a neonicotinoid weaken honeybees (Apis mellifera)

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