New scientific research suggests that pesticides have a lesser effect on bees than first thought. The debate took to the airwaves last week on BBC’s Radio 4, here’s the full transcript…

Charlotte Smith (Farming Today, BBC Radio 4): Insecticides may not be as bad for bees as previously thought, according to the American researcher who’d linked bee deaths with a type of insecticide, neonicitinoids. Dr Jeff Pettis from the US Agricultural Research Service now says the chemicals don’t appear to have as big an effect on bee health as he first thought. In the US honey bee numbers have fallen by a third and here too there’s been a decline in the bee population. Well as we’ll hear in a moment environmentalists and the pesticide industry disagree on the safety of neonicitinoid insecticides which are applied to seeds and so are taken up by the growing plant…

Dr Pettis first made the link between these chemicals and bee deaths after lab tests.

Dr Jeff Pettis (US Agricultural Research Service): In the lab it seemed clear there was this interaction between very low levels of one of the neonicitinoids and the pathogen. The pathogen went up when they were exposed. Surprisingly though when we went back to those colonies in the field and we had a number of replicates, ten replicate colonies of each one, and we looked at those colonies over time, ‘cause we continued to feed them the pesticide in the field, we didn’t see any change in nosema levels.

CS: So can we conclude that neonicitinoids are safe for bees?

JP: They’re safer than some of the older chemistries certainly. There’s one, one caveat to are they safer, they actually move systemically in the plant so plants, they can either treat the seed or you can treat the soil, the plant will take this up, the bees could be exposed in their pollen and nectar.

CS: Is it really that we don’t know enough about the effects of these insecticides so perhaps there’s an argument for applying the precautionary principle when it comes to using them on farms?

JP: The bulk of evidence over the past ten years in, in a variety of crops has been that bees in some cases are doing better next to crops that used to have other heavy pesticide use.

CS: Knowing what you know would you use a neonicitinoid insecticide?

JP: I might use it in place of a conventional, more conventional one that I know has higher toxicity. So in that sense yes, I think the, the prudent approach is to try to produce food using the, the best methods available. These compounds, they have replaced these more harsh chemicals that were really detrimental to bees, so it really is a balancing act.
I’m doing the research because I’m concerned, I’m highly concerned about pollinator health. But right now I think the balance has to tip in, in favour of their continued use in agriculture, mainly just because of the food production demands that we’re under.

CS: This is though something of a U turn on your original findings which linked neonicitinoids to damaging bee health.

JP: When I was asked about them a few years ago I was surprised by the level of response in, in the lab at very low levels. And with a bit of time in looking back at the colonies as a whole in the field and not seeing the same response, which I definitely would have predicted from the lab studies, it meant that things just aren’t as simple as sometimes they appear.

CS: So from your own research do you conclude that it is a good idea to use neonicitinoids or not?

JP: In light of the evidence that I have to date I would say their use on certain crops is still justified. I think we have to look almost crop by crop. I really can’t give a yes or no answer. It’s, it’s a gradient.

CS: Dr Jeff Pettis from the US Agricultural Research Service.

Listening to that are Matt Shardlow from Buglife, the invertebrate conservation trust, and Dr Julian Little who’s from Bayer Cropscience.

So Matt Shardlow this is all a balancing act.

Matt Shardlow (Buglife): One of the difficulties here is a scientific difference in how easy it is to do lab work and how easy it is to do field work and there’s an awful amount of evidence showing a range of effects in lab work where bees that are exposed to really tiny quantities of neonicitinoids, smaller than they would encounter in the field in pollen and nectar are, are massively impacted in terms of their health. The difficulty with field studies is that it’s much harder to get the information and to control the condition so that your results are scientifically valid. And Jeff Pettis’s …

Dr Julian Little (Bayer Cropscience): But that’s the reason why you have to do those field studies, because if we were just to take laboratory studies as Dr Pettis said earlier, if we’d have just taken the responses from the labs then we wouldn’t have insecticides out there. It’s not surprising in the end that insects …

MS: Julian if I could just finish, as I, as I, Julian …

JL: … are affected by an insecticide (indistinct).

CS: Dr Little you’ve, you’ve made your point, let Matt Shardlow finish his.

MS: So a lot of the studies haven’t been published, they haven’t been peer reviewed. They’re often done over two days and they’re not going to show chronic effects. The work that has been published has now been scientifically reviewed by James Cresswell of Exeter University and he found that even the published work wasn’t able statistically to show the impacts that you would predict from the lab work. And we also have to consider that some of the invertebrates that we’re looking at, for instance moths and butterflies which are also pollinating insects, are orders of magnitude more sensitive to these chemicals than the bees are.

CS: But what Dr Pettis made very clear is that there is no clear yes or no answer here. It’s shades of balancing. So given that we have to feed an increasing number of people don’t we have to just accept that we manage this risk and get on with it?

MS: Well I think those are very similar arguments to the arguments that were used just a few decades ago about DDT aren’t they, you know? And it does take a bit of time for the science to come about through independent means that shows the impacts are big on wildlife and on pollinators. Only yesterday we revealed that in the UK the numbers of incidents involving mass bee deaths from neonicitinoids is on the rise. It’s gone up from nought per cent in 2008 …

Dr Julian Little: No that’s (indistinct) clearly not true and …

MS: … to twenty seven per cent last year in 2010. And when we …

CS: But that’s tiny figures you’re talking there, isn’t it? You’re talking about fifteen incidents altogether and maybe three or four of them might be linked to neonicitinoids.

JL: The idea of saying neonicitinoids, you know, if we were to suspend their use we’d see a big improvement, well that was tried in France for nearly ten years. The result, no improvement whatsoever in bee health.

CS: I’m going to have to bring this discussion to a close. Dr Little do you have any concerns that you are taking risks with something we don’t fully understand yet ‘cause we haven’t given it enough time?

JL: What’s really interesting is that all of the work that’s being done in the field suggests that if used appropriately these products do not pose a risk to insects, important insects such as the honey bee.

CS: Matt Shardlow?

Matt Shardlow: When we put together the Buglife report in 2009 summarising the evidence Bayer and others in the agriculture industry were very keen to point out that there weren’t any mass deaths of bees as a result of these neonicitinoids, but we found out that there are. So you’ve got this accumulation of laboratory studies, very, very weak field studies that aren’t conclusive and then the incoming of new information about increasing bee deaths being reported through the Government. So we think there’s a picture here of, of a chemical where the evidence is building and building that these are causing a damage to the environment and to pollinators.

CS: Matt Shardlow from Buglife and Dr Julian Little from Bayer Cropscience in a rather echoey meeting room, apologies for that. It’s a subject I’m sure we’ll be coming back to.

Last month, researchers at the University of Illinois and the U.S. Department of Agriculture released a study that is the first to identify a single cause of the colony collapse disorder that has been killing off bees across the world. Please find below a selection of articles and blog posts on the matter published since then:

• DNA clue to honey bee deaths (BBC)
• Cause of Colony Collapse Disorder Identified? (The Daily Green)
• Scientists discover virus that could explain drop in bee population

(The Times)

• Bee genome gives killer clue to colony collapse disorder (New Scientist)
• Genome Study May Have Solved Bee Colony Collapse Mystery (SustainableBusiness.com)
• Pesticides still suspect for bee problems (Green Chemicals)
• Missing Bees? More Reasons Why and How to Help (Greening Families)
• Disappearing bees are lost in translation

(Not Exactly Rocket Science)

• Bee Genome Study Reveals Cause of Colony Collapse Disorder (Environment News Service)

At the Forum for the Future of Agriculture (see previous posts below) we spoke to Luca Montaranella, who is with theLand Management and Natural Hazards Unit at the Institute for Environment and Sustainability (IES). The IES is part of the Joint Research Centre (JRC) of the European Comission, its role being to provide scientific and technical support for the conception, development, implementation and monitoring of European Union policies.

In this clip, Mr Montarenella expressed his doubt over claims made at the Forum that there was plenty more land available for cultivation of crops around the world, and spoke of his institutes’s collaboration with EFSA in an attempt to make informed science-based decisions on matters such as pesticides regulation.

Asked about their views on the revision of current legislation governing pesticides in Europe, the scientists who signed the Declaration of Ljubljana last week, had the following to say:

To view highlights from other interviews, scroll down this page to view other blog entries, or to view the full interviews visit our YouTube.com channel.

Here are some more clips from interviews recorded at the scientific workshop in Ljubljana, Slovenia, last week (see other blog entries below). Dr Ian Denholm, Rothamsted Research, UK, speaks about the need for radical steps to meet the growing demand for food in Europe, and Lise Nistrup from Aarhus Universitet, Denmark, outlines the effects of pesticides on crop yields.

The full interviews and other material are available on our YouTube.com channel

Last night, I attended a press conference following a scientists’ workshop on the impact of the proposed revision of the EU’s pesticide legislation (Directive 91/414). Ian Denholm from the Rothamsted Research institute, presenting the workshop’s conclusions, pleaded to EU legislators to involve scientists in a thorough risk-based assessment of the proposed legislation, which he said has so far not been the case. View our video clip below to hear Ian’s remarks.

Other interviews from the event are being posted to our YouTube.com channel in the coming days.

Click here to read the scientists’ “Declaration of Ljubljana” in full or here to read a press release on the event from the Agricultural Institute of Slovenia.