In the UK, we are constantly told that field studies for pesticides offer the favoured and realistic method of assessing risk of pesticides to bees. In contrast, doubt is often cast over independent laboratory studies.
On 13 September, Defra published an analysis of the results of its review of research done earlier in the year on the effects of neonicotinoid pesticides on bees. DEFRA is the UK Department For Environment, Food And Rural Affairs. It relies on various departments to conduct different aspects of services that inform and support DEFRA, and two of these departments include FERA (Food And Environment Research Agency) and CRD (Chemical Regulations Directorate).
I read the report, and it was clear there was a regular theme running through the comments that CRD made with regard to the independent scientific studies, some of which were laboratory studies. I have included them on the right.
Can you spot the recurring theme?
Well, it seems at least Bayer Cropscience would agree with CRD. They also seem very keen to suggest that what is important is ‘What’s happening in the field” as demonstrated in their response to the Pettis study (below).
So one wonders:
"just how good are regulatory field tests for pesticides, and do they protect our bees?"
Aside from the fact that some of the studies featured right, were at least partial field studies anyway, nowhere that I am aware of, do FERA/CRD/DEFRA justify:
…Afterall, their report also states:
Well, EFSA, the
European Food Standards Authority, despite various controverial influences from industry, conducted a review: Scientific Opinion on the science behind the
development of a risk assessment of Plant Protection Products on bees (Apis
mellifera, Bombus spp. and solitary bees), and they have found
many MAJOR weaknesses with the regulatory standards for the field tests for pesticides.
But this did not surprise me, having read the guidelines myself. The field test guidelines EPPO170 are devised, it appears, by a group of pesticide manufacturers and those related to the industry (e.g. providing consultancy services), as well as a sprinkling of government civil servants, such as Helen Thompson and Selwyn Wilkins of FERA.(see work of the EPPO - opens new window).
Note the quote:
"At the ICPBR- Bee Protection Group 10th Symposium (Bucharest, 2009-10-08/10.....the WGs (working groups) presented proposals for the revision of EPPO Standards, which were discussed in order to hear the expert comments and recommendations of all 79 participants and to reach a consensus."
(see pages 158 -159 - opens new window).
So who were the 79 participants? They were mostly industry related people.....
Unfortunately, I don’t have sight of a manufacturer’s regulatory field test for pesticides, but there have been scandals in the USA over Clothianidin, relating to poor standard field study data, and we know that our regulatory field study guidelines are lax.
But we do have a report written by FERA on behalf
of DEFRA. It can be found on
It is a report that was produced in reaction to the concerns following a study by Girolami et al. (This study suggested that if bees consumed guttation drops (excretions of xylem fluid) from corn treated with neonicotinoids), they would die in minutes. Indeed, bees have been found to consume guttation drops. German beekeepers even investigated this themselves). Please note that neonicotinoids are 'systemic', meaning they permeate the whole plant and leaves - they are designed this way in order to kill insects that may chew on the leaves and suck on the sap.
In the report, FERA
outline 3 different studies:
- A Swiss government field study - one that conforms to EPPO 170 standards, it appears,
- A study by Shawkti looking at guttation from plants treated with a pesticide that was NOT systemic!
treatment of the Girolami study is in contrast to their treatment of the Swiss
study which is a deeply flawed as you'll see...... but first...
FERA state, with regard to guttation:
It's unfortunate that many will be misled by FERA's summary of Girolami's study - which in itself has to be read in its ENTIRETY (and probably a couple of times) to be properly grasped.
The Swiss study was called: “Presence of Clothianidin in Hives (Monitoring)”, and the objective of this study was “Quantitatively and qualitatively establish the presence of neonicotinoids (clothianidin)”
The field study investigated clothianidin residues in guttation, pollen, honey and dead bees. This is FERA's full summary from document:
Well it's interesting. In this deeply flawed experiment, the only part that could be considered a little robust was the measuring of clothianidin in the guttation samples - of which the authors found high concentrations. FERA do not draw attention to the fact that the guttation levels are considered high - and the figures will mean little to those 'not in the know'.
And was the experiment appropriately designed to "assess risks to honeybee colonies" as FERA state above? No, but FERA omit to mention this.
There were 2 elements to the test.
- A 2 hectare field was used – this is TINY - foraging bees will fly several kilometres – EFSA state that even at only 2.5 km - a realtively short flying distance, this corresponds to a theoretical foraging area of 19.6 km2, i.e., about 2000 hectares, in contrast to the 2ha used in the study.
- Only 36% of this tiny field was sown with clothianidin, the pesticide that was the subject of the study!
Given that FERA keep wittering about ‘field
realistic conditions’, can anyone let me know of any modern agricultural crop
field, where not only is the field itself tiny, but only about a third of it is
actually sown with the crop? Because I
don’t know of such a field! There is no criticism by FERA of the study with this regard. And please remember that field studies fail to take account of bees not returning to the hive (perhaps due to death or disorientation, for example).
So what they are saying is, 74% of this tiny field had no clothianidin at all - the very substance they were testing for!
Well, to be fair, the EPPO 170 guidelines state the field should be at least 1 ha in size, but they don’t stipulate it has to be sown completely with the pesticide being tested. It turns out that what was treated with clothianidin in reality, were 8 rows of corn, that were by the side of wildflower strips, close to apple trees and dandelions.
The rest of the field was sown with:
The author does not state what proportion of the field was treated
each with Mesorol, Gaucho and Cruiser.
The study does not even refer to these other pesticides later – so we
don’t know anything further about residues of other neonicotinoids. FERA do not draw attention to this point either.
Anyway, colonies with 20,000 bees each were installed by the side of the clothianidin treated field (with just 8 treated corn rows by the side of wildflower strips). 6 colonies of bees were used on this tiny field – 3 on each side – in reality, these colonies must have been close together – a regulatory field trial fault also identified by EFSA.
- 4 colonies from the sample of 6 (2 from each side) were used for monitoring of dead bees collected in traps at the hive. Pollen and honey samples were collected from the remaining 2 hives and were analysed for residues of clothianidin. In the case of the honey, the samples were taken 3-5 weeks before and after planting the corn.
- The trial began 17th April – the seeds were sown April 23rd. The trial lasted ONLY 50 days from April 23rd (where April 23rd = 0 in the summary table). 50 days (also includes the time taken for the corn seedlings to appear) is certainly insufficient time to see:
- even if the field conditions had been sufficiently realistic to gather robust data (taking into account that Bayer CropScience in their leaflet “The Secret Life Of Termites” (which are colony insects like honey bees) refer to a time period of 3 months to kill a colony).
- Guttation was collected 14 times and analysed in the lab for clothianidin.
The second field test was only 200m to 300m from the first field test. The field was surrounded by wildflowers, dandelions, clover. The bee colonies were placed on either side of the 1 hectare field in a meadow, onto which a strip was built (what size?) and upon which, seeds treated with Poncho (clothianidin) were sown using a mechanical seeder. 3 honey bee colonies were placed on either side of the meadow 16 days before planting time. During this time, the bees would have been busy foraging elsewhere, building stocks in the hive. The rest of the field study is of the same standard of ‘science’ (if you can call it that) as above. Clothianidin residues were measured, with predicable results.
The authors find "no significant mortality" of bees (although disorientation effects and deaths of bees outside of the hive due to poisoning would not of course, be recorded with this flawed field study in any case). They find, however, 10 dead bees per day (in a bumble colony, losses of 10 bees per day would be devastating, since a colony may typically only consist of about 160 bumblebees).
They do not detect residues of clothianidin in pollen and honey, with the exception of one sample of pollen (probably because the bees were foraging on flowers flowers they prefer). But they do detect contamination in ONE sample. The authors state this is likely to be caused by increased exposure to clothianidin of the dandelions close by, due to frequent use of the field for trials. That's an interesting admission, that could have several implications:
........but since during their unrealistic experiment they haven’t found any clothianidin residues in dead bees, honey or pollen during the time period the corn was guttating, the authors conclude this must mean the guttation doesn’t pose a threat. But they advise that if water is of limited availability to the bees, then beekeepers should engage in good beekeeping practice, by supplying water in the beehive.
Could some-one also ask them to do the same for the wild bees and invertebrates at risk as well, please?
Within their discussion they refer to bee poisoning cases in
Germany, and state that no such observations have been recorded in this
experiment. Could that be because the
German situation reflected reality, where as this unrealistic Swiss Government study
does not? I suspect this is the case.
FERA go on to summarise a further study by Shawki et al (2006). It should be noted that this study does not add any weight at all to the notion that guttation from crops treated with systemic insecticides, is not harmful to bees. Nor does it support in any way, the findings of the Swiss study above. The fact that the crops were treated with a non-systemic insecticide seems highly relevant. This is not explained by FERA, nor is it properly explained why guttation results would be so different from those in the other studies. As such, FERA are omitting important information that will potentially mislead the reader of this report.
FERA refer to the unrealistic Swiss study again (right), to cast doubt on other evidence suggesting that guttation could be highly toxic for bees.
So they used an unrealistic and dodgy study in Switzerland to cast doubt on the credible, independent data on guttation..........)
And so what can we conclude from all this? How about....
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“Due to the artificiality of the test design and dosing regime, there are uncertainties regarding the risk in a more realistic field exposure situation”.
“The key question for this study is how far it illuminates the likely real situation at field level - are the exposure and the resulting effects seen under normal conditions?”
“The following points require consideration in trying to interpret this study: whether factors such as exposure are in line with field situations”.
“The key issue is how this relates to potential exposure under field conditions – i.e. will bees be exposed to this level of pesticide under field conditions?”
“There is no information regarding the relevance of the concentrations given to the bees – i.e. were the levels appropriate and/or realistic?”
"It is unclear as to the relevance of the concentrations tested and hence whether the results can be extrapolated to the field situation”.
“the issue of detoxification and the relevance of diet should be considered under realistic field conditions.”
“the next logical step would be to employ this methodology at the field scale to see if the effects observed in this study were replicated under field conditions”.
“As regards the effects seen, it is important to note that they need to be related to what is likely to be encountered either in the hive (i.e. were the rates used realistic in terms of exposure to tau-fluvalinate) or in the field (i.e. were the rates used realistic in terms of what a worker honey bee is likely to encounter in the field.)”