Probing pesticide impacts

Probing pesticide impacts


THE European Union is going to spend two years figuring out something that is of interest to farmers, beekeepers and environmentalists alike: do neonicotinoid pesticides cause lasting damage to pollinating insects like bees?


THE European Union is going to spend two years figuring out something that is of interest to farmers, beekeepers and environmentalists alike: do neonicotinoid pesticides cause lasting damage to pollinating insects like bees?

On one level, it has to be expected that pesticides will be capable of killing bees, said Australian Honey Bee Industry Association executive director Trevor Weatherhead.

But in Australia, Mr Weatherhead reports that beekeepers haven't seen the calamitous collapse of bee colonies experienced in Europe and the United States.

In the US, some 10 million bee hives worth $2 billion have been lost in the past six years to a still-mysterious phenomenon called Colony Collapse Disorder (CCD).

Europe is experiencing a similar wipeout of pollinators.

Last week, in a quest for answers, the EU placed a two-year suspension on three classes of neonicotinoid pesticides: imidacloprid, clothianidin and thiamethoxam.

It's a suspension, not a ban, because it's complicated.

In the lab, the effect of neonicotinoids is clear. The pesticide compounds build up in the insects and hives, and gradually affect behaviour and reproductive success, eventually killing the bees.

Recent Scottish research also found that neonictonoids in combination with coumaphos damaged bees' ability to learn. After four days exposed to a combination of the chemicals, nearly a third of bees failed to learn or performed poorly in memory tests, losing their ability to forage.

But so far, these effects haven't been replicated in the field.

The EU suspension is intended to give researchers time to build on scant field research, along with the hope that the carnage being inflicted on pollinators will stop in the absence of the chemicals.

University of New England entomologist Nigel Andrew is among those who wants to see a similar suspension, for similar reasons, in Australia.

There haven't been many field trials done around the world on the effect of neonicotinoids, Dr Andrew said, partly because the number of variables make general conclusions difficult.

Even within a single species of bee, there is a big range of variation and regional adaptation. Bees' response to the environment alters with the weather or parasite pressures, and a managed hive does not have the same health profile as a feral hive.

These factors can affect how susceptible bees are to new chemicals in the environment.

Most of the research focus has been on managed hives of the honey bee, Dr Andrew added. In Australia, most on-farm pollination comes from feral hives, and from native bees and other important but unrecognised pollinators like hoverflies.

Given the largely undervalued importance of these insects, Dr Andrew thinks it is in everyone's interest to assess the risks to their health.

"It's important from a precautionary point of view that we properly test the implications of these chemicals," Dr Andrew said.

"We don't want just a moratorium on their use. That would be a waste if we don't do some good-quality research on their effects."

Trevor Weatherhead said the AHBIA is keeping a watching brief on the issue, but at present it isn't alarmed about neonicotoids because, from the Australian apiarist's perspective, there isn't reason to be.

There are some interesting anomalies in the picture, Mr Weatherhead observed.

Neonicotinoids obviously have an effect on bees, but while the US and the EU have seen catastrophic collapse of some bee populations, that has not been the case in Canada, where neonicotinoid-treated canola can fill the prairie for as far as the eye can see.

The AHBIA is waiting for the pollinator review soon to be released by the Australian Pesticides and Veterinary Medicines Authority (APVMA) before instructing affiliated researchers on the next step.

Australian registrations for the neonicotinoids suspended in the EU include:

  • Clothianidin – SHIELD

Cotton Australia has listed best management practive for growers using neonicotinoid pesticides at:

APVMA review underway

As international concern mounts about the effects of neonicotinoid pesticides on pollinator insects, the Australian Pesticides and Veterinary Medicines Authority (APVMA) has launched a deep review into the issue.

Started in August 2012, and with a draft report scheduled for release in mid-2013, the APVMA review is consolidating past research, scientific advice and the views of stakeholders in the agriculture, apiary and pharmaceutical industries to map the way forward on neonicotinoid use.

At present, the APVMA is not indicating it will favour an EU-style suspension. In an update on the review, the Authority noted:

  • a European Food Safety Authority report saying that there isn't enough data to form conclusions about the effects of neonicotinoids on pollinators. (In January, EFSA noted a large number of "data gaps" that needed to be filled before conclusions could be drawn);
  • the UK Government’s independent Expert Advisory Committee on Pesticides, which concluded that there is no evidence of neonicotinoid impacts on bees in the UK;
  • that various EU countries have put their own suspensions on neonicotinoids, some of which were subsequently lifted;
  • in-field monitoring in Europe and Canada that suggests revising stewardship practices can help minimise risks.

The story Probing pesticide impacts first appeared on Farm Online.


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