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Fifth report links neonicotinoid pesticides to bee decline

23/10/2012 06:48:27

Bees forage widely and are likely to encounter more than one pesticide.

Study reveals combination of pesticides seriously harms bumblebees

October 2012. A new study reveals the combination of two pesticides widely used on agricultural fields can have damaging effects on bumblebee health and behaviour.

The Government-funded scientific report, published by Royal Holloway College, University of London as part of the Insect Pollinators Initiative is the fifth major scientific report linking harmful pesticides including a neonicotinoid to declining bee populations. Wildlife charity, Buglife - The Invertebrate Conservation Trust welcomes the new research as yet another strong piece of evidence linking bee declines to pesticides.

Matt Shardlow, Buglife Chief Executive said "This report is yet another piece of evidence linking bee declines to pesticides. It is vital that the Government takes immediate action to protect our wild pollinators such as bees, bumblebees and hoverflies by suspending the use of these harmful pesticides before it is too late".

"In the UK the current methods of testing and approving pesticides is totally insufficient and only considers lethal doses of single pesticide. This study is so important because in the wild bees do forage widely and are likely to encounter more than one pesticide. Efforts need to be made to improve the pesticide regulation process to ensure proper testing of the effects on all wild pollinators are considered before licensing".

The study revealed that the bumblebees suffered impaired foraging, increased number of deaths and in some cases failed colonies when exposed to exposed to a neonictonioid and imidacloprid pesticide

Buglife is feeding into the Government's consultation on a UK Pesticides Action Plan which it has to submit to the European Commission under the Sustainable Use Directive by the end of November.

Pollination worth £17 billion to EU agriculture
Pollination by insects is worth £17 billion/yr to EU agriculture. A reduction in pollinator populations of just 5% will cost agriculture more than the £0.8 billion economic benefit of using neonicotinoids that is claimed by the pesticide companies.

85% decline in queens
The most worrying scientific paper found an 85% reduction in the number of queens produced by bumblebee nests that had been fed, for just two weeks, with field realistic levels of neonicotinoids. The strongest criticism that Defra makes of the study is that "It may be significant that the control bees consumed nectar and pollen whereas the treatment bees were given a different diet of treated pollen and sugar water." It may be significant, but it would be fanciful to think that this difference explained the 85% reduction in breeding success; it is much more probable that it was the insecticide, not the water.

Another paper showing that bees are killed by dust released when neonicotinoid treated seeds are planted is excluded from the main body of the report and apparently neutralised in an appendix by the statement that "This route of exposure will be considered as part of the new EU guidance document". This can hardly be considered to be a solution!

To counter that scientific evidence of damage and impairment to honeybees in published papers Defra refers to unpublished and unavailable honeybees studies undertaken by pesticide companies (not bumblebee studies - such studies do not exist for non-honeybee pollinators). This use of these unpublished regulatory studies is rather undermined by the statement in the report from the Government's Advisory Committee on Pesticides that "the regulatory studies were not designed with detailed statistical analysis in mind, and their power to detect statistically significant changes is not established".

Wild bees have annual lifecycles and small reductions in breeding success could trigger population declines, the Defra report presents no evidence that neonicotinoid insecticides are not killing, disabling and impairing wild bees, thereby contributing to their disappearance from the countryside.

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