Insects and Insecticides

Written evidence submitted by the Advisory Committee on Pesticides

Executive summary

· The Advisory Committee on Pesticides (ACP) is a statutory independent scientific advisory committee. Members are appointed following open competition and advise Ministers on matters relating to the control of pests and particularly on the approvals of pesticides in the UK. There are clear arrangements in place to manage any potential conflicts of interest to ensure that the advice we provide is independent.

· Effective risk management for pesticides is dependent upon a good understanding of a number of important factors including: the properties of the substance, the way it is applied, the type of exposure experienced in practice, and the dose actually received.

· Risk assessments supporting current UK approvals for neonicotinoids are based on a standard regulatory package defined at EU level. These assessments have proved to be acceptable in relation to the authorised uses of these products in line with the standard requirements. We recognise that the standard requirements do not include some of the specific sub-lethal effects suggested by recent academic studies. However, satisfactory data have been supplied for neonicotinoids based on field studies in honey bees, which indicate that in practice there is no difference between colonies foraging in treated and untreated crops over several years of exposure and considering a number of important end points associated with bee colony sustainability. In addition, surveillance data have not highlighted specific problems occurring in the UK. This is why at present we have not advised any regulatory action.

· Recent academic research, which is being closely monitored by the ACP, has suggested possible effects on bee behaviour which are outwith those measured by the defined regulatory package. Also, behavioural effects have been detected in bumble bees, although risks to bumble bees are not currently assessed by regulatory studies and few data on them are available.

· However, such studies have not established convincingly that the exposures employed experimentally are likely to occur in nature.

· Further field-based work has been commissioned by Defra. Findings are expected early in the New Year and will provide better information on what exposures are actually occurring, and what the effects are in practice on bumble bees. Bumble bees are not currently routinely tested in regulatory studies.

· Should the field data on bumble bees indicate a significant risk that requires managing, we will consider carefully what the appropriate steps should be, and will provide advice to government that is supported by a more secure weight of evidence than exists at present. If use of neonicotinoids were to be restricted, this could result in greater usage of other insecticides known also to be hazardous to bees. Advice will therefore need to reflect risks to bees that could arise from the available alternatives.

· There is currently no evidence of harm to human health in either UK surveillance or the published literature following use of neonicotinoid insecticides in accordance with UK approvals.

· It is clear to us that appropriate risk management based on good scientific data is the way forward in this very complex situation and that important information is expected shortly.

· The ACP is not complacent about the current situation. We will consider any new information as it arises and are keeping the situation under close review.

1. The Advisory Committee on Pesticides (ACP)

1.1 At the outset it might be helpful to provide a little background about the ACP and its work. The ACP is a statutory independent advisory committee. Membership is drawn largely (but not entirely) from academia and members’ skills reflect the range of expertise necessary to consider the scientific evaluation of studies supporting applications for approval of pesticides. We also have two lay members. Current membership is listed on our website and is attached as Annex 1.

1.2 Appointments are made following open competition and follow the requirements of the Office of the Commissioner for Public Appointments (OCPA). All of our members are independent and are required to declare any interests they might have in the pesticides industry, both on an annual basis and ahead of discussion of each issue we consider. As you are probably aware, university departments are required to seek funding from a variety of sources for their research programmes. Typically some funding comes from government, research councils, non-governmental organisations and industry. All members of the committee comply with the Nolan rules and all declare any interests they may have. The ACP has rules that govern how members might participate in discussion if they have interests to declare. These rules are published on our website here:

1.3 Members interests are recorded annually in our annual report and are also recorded in the minutes and detailed record where interests are declared on specific items discussed at our meetings. Indeed, one member, Dr Harris, has declared a personal interest during our discussions on neonicotinoids and bees as she has worked on clothianidin residues in food in the past, and consequently has played no part in the formulation of advice and has left the room for the duration of our discussions on the topic.

1.4 We have provided a short outline of our role and a summary of the approvals process in our annual report and this is attached at annex 2. Our annual reports are on our website here: .

1.5 A key consideration in evaluating all of the data submitted in support of applications for approval of pesticide active substances and their products is to determine what dose of a substance causes toxic effects, what these are and what dose causes no observed adverse effects. This ‘hazard identification’ stage of an evaluation identifies what potential effects a substance could cause. The ‘risk assessment’ stage of the evaluation calculates the exposures (doses) that are likely to occur as a result of the proposed use and then assesses the possibility of the potential effects being realised in practice (i.e. whether a dose that causes effects may be experienced when the plant protection product is actually applied to crops). The approval of plant protection products requires there to be an acceptable risk assessment as defined by the current EU legislation (Regulation 1107/2009 of the European Parliament and of the Council). The data requirements for active substances are defined in Commission Regulation 544/2011 and those for products in Commission Regulation 545/2011. Furthermore the requirements for evaluation and authorisation of plant protection products which Member States are required to follow are set out in Commission Regulation 546/2011- the ‘Uniform Principles’.

1.6 It is essential when considering information about pesticides to be aware of the material difference between hazard (the potential for harm) and risk (its likelihood), as outlined above.

1.7 It is fully accepted that the neonicotinoid insecticides (and indeed most other insecticides) are a hazard and are toxic to bees in laboratory studies at identified doses. Whether such toxicity is likely or not to arise in practice, however, will be determined by uses made of these pesticides and the extent of exposure in bees. (i.e. to what dose, if any, are they actually exposed).

2. Neonicotinoids

2.1 Imidacloprid was first authorised for use as an insecticide in the UK in 1993. Since then there have been a number of authorisations for use of insecticides containing neonicotinoids in the UK as follows:

2.2 Plant protection products:

Acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam are authorised in products for use in plant protection on a wide range of agricultural and horticultural crops in a number of formulations including seed treatments, granules, sprays etc. Products containing neonicotinoids are also available for use in the home garden.

Table 1. Initial UK approvals for the neonicotinoid insecticides in plant protection products were as follows:


ACP consideration

Initial approval date

First Use


(EU annex I listing 2004)

ACP 14 (319/2006))


Home garden soil drench based on the EU evaluation


ACP 6 (293/02)

ACP 7(311/05)

2002 beet

2005 cereal

Seed treatment for sugar/fodder beet


ACP 67 (226/93) published evaluation doc 73, ACP 18 (257/98)

ACP 237 (276/00) ACP 66(283/01)

1993 for sugar beet,

for cereals 1998, for oilseed rape 2001

Seed treatments for sugar beet, winter wheat and winter barley, oilseed rape


ACP 300 (278/00))


Foliar spray on apples


ACP 6 (319/2006))


Seed treatment on sugar beet

2.3 Biocidal products:

Imidacloprid products have been approved for control of ants, cockroaches and flies; thiacloprid wood preservatives have been authorised. Applications for use of clothianidin, thiamethoxam, acetamiprid and dinotefuran are all under consideration through the EU regulatory system for biocidal products.

2.4 There are also known to be veterinary medicine uses. Veterinary medicines are the responsibility of the Veterinary Products Committee.

2.5 This paper considers the plant protection product uses of the neonicotinoids, as these uses are more likely to result in exposure for bees.

3. The European Food Safety Authority (EFSA)

3.1 EFSA play an important role in Europe as ‘guardians’ of risk assessment for plant protection products. In addition to their important programme of peer review (of evaluation and risk assessment of all Member States’ work as ‘Rapporteurs’ evaluating data submitted in support of active substances for use in plant protection products), they also draw advice from a number of expert advisory panels with membership of experts drawn from across the EU.

3.2 Members of the Environmental Audit Committee will probably already be aware that EFSA is also currently undertaking a number of specific activities associated with the assessment of risk to bees.

The specific questions to be addressed by the Inquiry.

4. The use (or abuse) of evidence in this particular case, for setting policy and regulations on pesticides

4.1 We should stress that the ACP takes its responsibilities in providing independent advice to Ministers based on sound science very seriously. It considers the potential risks to bees and other non-target insects from the use of insecticides to be an extremely important issue. These potential risks were considered prior to all approvals for use in the UK. Furthermore, all approvals undergo regular routine review, but are also subject to review at any time should emerging data indicate a need to reconsider the risk assessment.

4.2 In this respect, potential harm to pollinating insects from neonicotinoid insecticides is an area of public and scientific concern and of intense research activity. Recent published literature indicates the possibility that there may be toxicity to honey bees and also to bumble bees considering outcomes such as bee behaviour, which are not required by the current EU regulatory assessments. The ACP has recognised the importance (and urgency) of keeping a close watching brief on this emerging science and its possible impact on current approvals for use, and has devoted considerable attention to developing concerns about risks from neonicotinoid insecticides to bees and other pollinators. Since 2008 the issue has featured in many of its meetings. Annex 3 provides a short summary of our discussions and links to the relevant parts of our website providing records of those discussions. Note that discussions were also held with the public at our open meeting in November 2011, resulting in the views from that meeting being passed to EFSA for further consideration as they develop revised guidance for regulatory testing in this area. Relevant correspondence is in Enclosure 3.

4.3 Our advice to Ministers in July 2012 (at annex 4) was based on a careful review of all of the studies available to us. These included the studies originally submitted by applicants for approval of products as well as studies in the published literature. (We understand Defra has provided detailed information on the regulatory requirements for plant protection products). We re-visited the regulatory studies on bees for thiamethoxam this year, particularly in the light of the studies by Henry et al and Whitehorn et al in 2012, which we also reviewed in detail, before providing our advice. We had previously re-considered imidacloprid bee studies in developing our advice on the ‘buglife’ report.

4.4 The regulatory data supplied by the applicants are unpublished. Regulatory data are of considerable commercial value and complex ‘data protection’ rules in the legislation govern how the data can be used in ways that protect their value. This is why the actual studies are not attached as a part of this evidence. However, the evidence can be made available to the Environmental Audit Committee on request to CRD.

4.5 In the interests of efficiency we have not included all of the work done by ACP and CRD on the neonicotinoids since the early 1990’s as the sheer volume is huge. However, if the Environmental Audit Committee wishes to see any more detail of our work we would be happy to provide it. The Environmental Audit Committee should be aware that a dossier supporting a single active substance is very extensive and in hard copy probably amounts to a stack about 1.5-2 metres high of A4 paper printed double sided.[Not published here. Deposited in the Parliamentary Archives].

4.6 As an example of an early evaluation of a neonicotinoid (1993) the published evaluation document for imidacloprid is provided as Enclosure 1. .[Not published here. Deposited in the Parliamentary Archives]. It is important to note that this was the evaluation that supported the first approval of imidacloprid in the UK. Subsequent approvals and further considerations in accordance with the EU legislation leading to EU annex I inclusion will have involved the evaluation of additional studies. (We can supply further details if required).

4.7 Our work also takes account of concerns raised by stakeholders. Our response to the ‘buglife report’ is provided as Enclosure 2, .[Not published here. Deposited in the Parliamentary Archives]. together with the paper we considered in formulating our response, and the further consideration by our Environmental Panel. We also include in Enclosure 3 an example of a response provided to a letter received directly from a stakeholder (ACP 9 (354/2012)).

4.8 The various papers we have considered at our meetings since May 2012 are at Enclosures 3 to 6 .[Not published here. Deposited in the Parliamentary Archives]. – together with the detailed record of our discussion of the papers.

4.9 We did not recommend regulatory action on neonicotinoid insecticides in July 2012 because there remained considerable uncertainty as to whether the adverse effects on bees (both bumble bees and honey bees) reported in the investigative research studies actually occur in real life field conditions. Indeed, the regulatory data made available to us included a well conducted field study using thiamethoxam indicating no difference in a range of relevant endpoints over a period of several years between honey bee hives in both treated and untreated crops. We are aware that EFSA have taken a similar stance to the ACP with respect to the current knowledge of bee safety and neonicotinoids.

4.10 We are also aware that other insecticides that could be used as alternatives to using neonicotinoids themselves pose some risks to bees, and loss of the use of neonicotinoids would be likely to result in an increase in the extent of use of some of these alternative insecticides (see below).

4.11 The ACP is not complacent about the current situation. An important part of our advice to ministers was that ‘the ACP will consider any new information as it arises and keep the situation under close review.’ We were aware in July 2012, when providing that advice, that key research likely to shed light on some of the uncertainties was expected to be reported early in 2013.

4.12 Since July, the ACP has become aware of a new report by Gill et al, published in the journal Nature on 1/11/12, which has been reviewed at the ACP’s November meeting for its potential to alter the regulatory climate. This most recent study provides additional information in suggesting a possible mechanism by which neonicotinoids may have an effect at population level. As such it reinforces the concerns already identified on the basis of the previously considered evidence, but still does not provide the clear evidence about field exposure in bumble bees from the UK situation that the Defra study (Defra project PS 2371) is designed to address. We anticipate considering initial results from this work at our January meeting and concluded that this short delay would not prevent effective regulatory action if the data indicate this is required. We noted that seed treated with neonicotinoids had already been sown this autumn, and that the much smaller proportion of spring-sown seed would already be in the supply chain for the 2013 harvest. Any regulatory action on seed treatments would thus mainly impact from the 2013 autumn sowings onwards.

4.13 In addition to considering applications for approval of active substances and plant protection products the ACP also plays an important role in developing regulatory science. For example there is considerable interest in assessing risks to both people and wildlife from mixtures of pesticides. The ACP has on several occasions discussed the issues associated with exposure to mixtures, and has concluded that joint effects are rarely more than additive in nature. For that reason, we have concluded that assessment factors routinely applied in risk assessments should generally be sufficient to account for potential mixture effects, although we do require some more specific consideration (particularly in human risk assessments) where a single product contains more than one active substance with clear potential to interact. There is also a considerable amount of development work in this area looking at the possibilities that might be afforded by probabilistic risk assessment.

5. The application of real-world – ‘field’ –data. What monitoring is there of actual – rather than recommended – levels of pesticide usage, and the extent to which that influences policy on pesticides.

5.1 There is a framework of monitoring schemes considering actual pesticide usage and its consequences for both human and environmental health. We understand that Defra has provided detailed information about the schemes.

5.2 Information from the Wildlife Incident Investigation scheme (WIIS) on bee incidents is perhaps of particular relevance to this Inquiry. Information from WIIS is included in enclosure 2 in ACP 6 (341/2010), and despite specific screening being in place, there had not been any positive detections of neonicotinoids in bees at that time.

5.3 To date we have not seen any data to suggest that UK bee populations have been in decline due to the use of insecticides, or that Colony Collapse Disorder is occurring in the UK. We are also aware that bee diseases such as varroa might be weakening bees to the point where insecticides are able to have a greater effect, but again, we have not seen any data to suggest that this is actually happening.

5.4 The various monitoring schemes feed back information to the regulatory process, often via the ACP. Where findings of monitoring suggest there is a need, these inform further action, whether that is further research to clarify mechanisms of activity recorded, or further regulatory activity.

5.6 One example of such activity is the current stewardship programme for products containing chlorpropham to identify the mechanism leading to occasional peak residues above the Maximum Residue Level (MRL) [1] in order to rectify the position. The ACP is actively monitoring this scheme involving chlorpropham, and has written to the relevant stakeholders indicating that it will take action if the current situation is not resolved to its satisfaction.

6. Any potential impacts of systemic neonicotinoid insecticides on human health.

6.1 Human risk assessment for plant protection products is completed in accordance with the Uniform Principles set out in EU legislation.

6.2 We understand that Defra has provided detailed information about the regulatory risk assessment for humans.

6.3 Given the very large margins of safety required in human risk assessment before an authorisation can be recommended, it is unlikely that use in accordance with the UK conditions of authorisation will result in any impacts on human health. However, as no experimental data are available on humans, in addition to the detailed risk assessment, the ACP also considers reports of suspected ill-health associated with pesticide exposure in the UK, and screens the published literature for reports of adverse health impacts that might be of relevance to UK pesticide use. Enclosure 7 .[Not published here. Deposited in the Parliamentary Archives].provides relevant abstracts from the published literature. None relate to approved use in the UK. Most seem to be reports of attempted suicide, mostly in developing nations. It is notable that the recovery from these events was generally within a matter of days with a relatively low level of mortality being reported. This contrasts to literature reports for some other insecticide classes which might be considered alternatives to neonicotinoids.

6.4 The three UK schemes reporting information on human health effects of pesticide exposure, National Poisons Information Service, (NPIS), Pesticides Incidents Appraisal Panel (PIAP) and Human Health Enquiry and Incidents report (HHEIS) have recorded very few reports involving a neonicotinoid insecticide. Details of the incidents reported are not included with this evidence to maintain patient confidentiality . Symptomatic reports were associated with not using the product in accordance with its authorisation. Symptoms reported as being associated with exposure to neonic o tinoid insecticides were transient and relatively minor, such as skin rashes and eye irritation .

6.5 Overall, therefore, monitoring has not identified reports of ill health in the UK associated with use of the neonicotinoid insecticides in accordance with their authorisations. We recognise that while each of the surveillance schemes has its own strengths and weaknesses, overall these schemes focus on acute ill-health and are not designed to identify long term consequences of pesticide exposure. A recent ACP working group has examined these schemes and made recommendations for future surveillance.

6.6 As with all pesticides, this position is kept under continuous review, and we expect to consider the next reports from the monitoring schemes in January 2013.

7. What alternative pest-control measures should be used, such as natural predators and plant breeding for insect-resistance, in a bid to make UK farming more insect- and bee-friendly?

7.1 The ACP is keen to see the development of sustainable approaches to pest management. This is often referred to as ‘Integrated pest management’ (IPM).

7.2 Nearly 10 years ago we published the report of a sub-group of the ACP that considered the alternatives to conventional pest control techniques in the UK. This report is on our website here. It is also available as Enclosure 8.

7.3 Since that report was produced, there have been a number of important initiatives aimed at supporting the development of sustainable agriculture in the UK. Some examples include:

· Introduction of the various levels of environmental stewardship agreements;

· Two projects considering regulatory approaches for biological pesticides (RELU and REBECCA) and an on-going review in association with the Pesticides Forum

· The UK biopesticides scheme

· A draft National Action Plan prepared for consultation (consultation closed on 22 October 2012) setting out many of the ways in which the UK supports development of sustainable approaches to the use of Plant Protection Products.

7.4 Despite these considerable efforts and developments, and the authorisation of more biological pesticides, it remains the case that effective control of important insect pests particularly in arable and some horticultural crops in the UK will continue to rely heavily upon the relatively few authorised insecticidal products for the foreseeable future. Maintaining a crop protection ‘armoury’ that includes insecticides with different modes of action is also important to minimise the risk of insecticide resistance developing in key pests.

7.7 Specialist growing techniques such as those required in organic production systems currently play an important but ‘niche market’ role in the overall agricultural production within the UK, and there are significant costs associated with these methods of production – often including lower yield. The latter is clearly of increasing importance when considering wider food security issues.

7.8 Thus, the main alternatives to use of neonicotinoids currently available to most farmers and growers are other insecticides. Annex 5 provides a short summary of acute toxicity data on honey bees for insecticides currently authorised for use on oilseed rape (OSR) as an example crop that is very attractive to bees. The data demonstrate that most of these insecticides present a potential hazard to bees. Risk management for all of these substances is therefore primarily about management of exposure, so that the risk of actual harm is limited. It is important to note that not all insecticides control the same pests, so the insecticides included in this list would not necessarily be interchangeable alternatives. Recent usage data for the neonicotinoids in the UK is at annex 6 to give a clear context to the Inquiry considerations. We understand that more detailed examination of alternatives has been provided by Defra.

7.9 It is very important that the careful scientific examination of possible impacts of the neonicotinoids is completed to ensure that an appropriate regulatory response is made to manage risk. Action on the neonicotinoids could result in greater usage of other insecticides. Both the neonicotinoids and most other insecticides have fairly low LD50 [2] values for honey bees (i.e. are toxic at low concentrations) and it would be quite difficult to identify from these data that there is a class difference in toxicity between the neonicotinoids and other classes of insecticides. We currently have virtually no data on bumble bees for other insecticides as it is not a standard regulatory requirement. The limited data we have seen e.g. in Gill et al (2012) indicate that under those experimental conditions exposure to lambda cyhalothrin alone (at a dose which is higher than is used in practice), also resulted in some significant effects on bumble bees.

Enclosures .[Not published here. Deposited in the Parliamentary Archives].

1. Published evaluation document 73 - imidacloprid

2. ACP 6 (341/2010) and ACP 6/1 (341/2010) initial consideration of the ‘buglife’ report and ACP response. Our environmental panel’s consideration of the additional points is ACP 12 (350/2012).

3. ACP 9 (354/2012) response to a stakeholder; ACP 7, 7/1, 7/2, 7/3, 7/4, 7/5, 7/6 (355/2012) papers on bees considered at meeting 355 plus the detailed record of discussion of that item at the May 2012 meeting.

4. ACP 6, 6/1, 6/2, 6/3, 6/4, 6/5, 6/6 (356/2012) and ACP 11 (356/2012) papers on bees considered at meeting 356 plus the detailed record of discussion of those items at the July 2012 meeting.

5. ACP 20, 20/1 (357/2012) additional studies on bees and detailed record of discussion at the September 2012 meeting.

6. ACP 12, 12/1, 12/2, (358/2012) additional studies on bees discussed at the November 2012 meeting and the advice just sent to Ministers.

7. Abstracts from the published literature on reported human health effects of neonicotinoids

8. ACP Report on alternatives to conventional pest control techniques in the UK

Annex 1

Current ACP membership (as at 16 November 2012)


Sadly, our current Chair, Professor Gabrielle Hawksworth passed away on 30 July 2012. She will be greatly missed by all her friends and colleagues.

Deputy Chairman

Dr Andrew Povey is Reader in molecular epidemiology at the University of Manchester. He was first appointed to the Committee in 2008 to advise on epidemiology and toxicology issues.


Professor Colin Brown is Professor in Environmental Science at the Environment Department of the University of York. This is his sixth year on the Committee.

Dr John Cocker is a Biochemist and Head of Biological Monitoring at the Health and Safety Laboratory, Buxton, Derbyshire. This is his fourth year on the Committee.

Mr Richard Davis is a retired Director of the Chemicals Regulation Directorate, who graduated in plant pathology and followed with a successful career in research in the use of pesticides in horticultural and agricultural crops and in pesticide regulation. He joined the ACP in Autumn 2011.

Ms Jennifer Dean is a Barrister, and is the ACP Committee Lay Member for consumer affairs. This is her third year on the committee

Mr Derek Finnegan is a regulatory compliance and safety specialist, with expertise in delivering technical and regulatory solutions to the food industry. He was appointed to the Committee in January 2012.

Dr Caroline Harris is Principal Scientist and Co-Director of the Centre for Chemical Regulation and Food Safety, Exponent International Ltd, Harrogate, North Yorkshire. This is her fourth year on the Committee.

Dr Martin Hare is Principal Lecturer at Harper Adams University College and Chair of its Research Degrees Standards Committee. He is an active researcher in pesticide efficacy, and joined the Committee in Autumn 2011.

Mr Philip Jackson is a self employed Health and safety Consultant, and is the ACP Lay Member for Environmental Issues. This is his third year on the Committee

Professor Ted Lock is Industrial Professor of Toxicology at the School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University. He was appointed to the Committee in January 2012.

Dr Peter Matthiessen is an independent environmental consultant in ecotoxicology, and is a former member of the Centre for Ecology and Hydrology, Lancaster Environment Centre. This is his sixth year as a Member of the Committee.

Dr Chris Morris is a Senior Lecturer in neurotoxicology at the Medical Toxicology Centre, University of Newcastle. He was appointed to the Committee in January 2012.

Professor Colin Ockleford is Professor in the Department of Medicine at Lancaster University and Visiting Professor in the Laboratory for Developmental Cell Sciences in The Department of Infection, Immunity and Inflammation at Leicester University Medical School. This is his sixth year on the Committee.

Professor Keith Palmer is Professor of Occupational Medicine at the University of Southampton, and Clinical Scientist at the MRC Lifecourse Epidemiology Unit. He is Honorary Consultant Occupational Physician at the Southampton University Hospitals NHS Trust. This is his first year on the Committee.

Dr William Parker is Director of the Horticulture Sector of the Agriculture and Horticulture Development Board. This is his fifth year as a Member of the ACP.

Professor Richard Shore is a vertebrate ecotoxicologist and Head of Site at the Centre for Ecology & Hydrology (CEH) at Lancaster. He is a senior researcher investigating the environmental impacts of contaminants, and has an Honorary Chair at Lancaster University. He joined the ACP in Autumn 2011.

Dr Andrew Smith is Director of the MRC Integrative Toxicology Training Partnership (ITTP), based at the MRC Toxicology Unit, University of Leicester. He joined the ACP in January 2012.

Dr Stephen Waring is Consultant in Acute Medicine and Toxicology, York Hospitals NHS Trust, and Honorary Senior Lecturer in Clinical Pharmacology, Hull/York Medical School. This is his fourth year on the Committee

Dr Simon Wilkinson is a staff scientist at the Medical Toxicology Centre, University of Newcastle Upon Tyne. He researches into routes of exposure to harmful chemicals, concentrating on dermal absorption and cutaneous metabolism. He joined the Committee in Autumn 2011.

Annex 2

The regulatory system

Most people agree that it is very important to control the pests,

diseases and weeds that threaten our food supplies. There are a

number of techniques to do this which are used by both professional

farmers and growers and by home gardeners. These include

techniques such as crop rotation, digging or ploughing, weeding

and the introduction of predatory insects or mites, nematodes and

parasitoids as part of integrated pest management (IPM) approaches.

Pesticides are included in these techniques for both professional

farmers and growers and home gardeners. Pesticides are substances,

preparations or organisms used to control specific pests, pathogens or

diseases or weeds. They include a wide range of different substances,

both naturally occurring and synthesised and a range of bacteria,

fungi or viruses that can be used in biological control.

Because these are products that are specifically designed to

have an effect on a living thing, pesticides, like medicines, are

subject to an extensive regulatory system and must demonstrate

that they can be used without unacceptable risks before they are

allowed to be sold.

This is a short explanation of the regulatory system currently in

place for pesticides, specifically designed for the general reader.

More detailed technical information (suitable for those seeking to

make an application for approval of a pesticide for example) is

available on the CRD website

[ ].

There is a large volume of work to do in assessing pesticides to

ensure they meet the requirements of the regulatory system. Much

of this work is now shared between the member states of the EU,

with one member state, known as the Rapporteur Member State

taking the lead responsibility for assessing the active substances

used as pesticides in the EU. An active substance can only be used

in a pesticide product anywhere in the EU if it meets the regulatory

requirements and has been approved by the member states.

The active substance in a pesticide product is the part of the

product that provides the pest control. Most products also include a

range of other substances that help to make the product suitable to

apply to protect the crops, for example the bait that will attract slugs

to eat slug pellets. These other substances are called co-formulants.

Each member state remains responsible for authorising all pesticide products to be used within their member state. This is so

that each member state can make a specific assessment of each

product taking account of differences in conditions that occur

across Europe that will affect how a pesticide can be used.

A number of government departments in the UK have a

specific interest in the authorisation of pesticides. The Department for

Environment, Food and Rural Affairs (Defra) takes the lead, with

important involvement from the Department of Health, the Food

Standards Agency, the HSE (HSE), and

the devolved authorities in Scotland, Wales and Northern Ireland.

The Chemicals Regulation Directorate (CRD) of the Health and

Safety Executive (HSE) prepares a scientific evaluation of

applications for pesticide product authorisation in the UK on behalf of

all of the departments. They also prepare evaluations of

active substances where the UK has been

asked to be the Rapporteur Member State for the EU.

The independent Advisory Committee on Pesticides provides

expert advice both to CRD and to the responsible ministers and

departments on all major issues relating to pesticides in the UK.

The scientific evaluation of a pesticide

This is a complex process involving the detailed consideration of a

huge database of scientific studies for each active substance and

pesticide product.

For the purposes of this document it is perhaps most

straightforward to outline the data that are considered and the

way in which information is used to complete the risk assessment

needed to meet the regulatory requirements for a new active

substance. Such applications must be accompanied by data

for a pesticide product as well. Details of data requirements and

evaluation times are given on the CRD website for different types

of applications for approval [].

The main components of the data package that typically would

be required for a new pesticide fall into the following seven areas.

1 Physico-chemical properties

The applicant is required to specify the chemical composition of

the product, its active substance, and any significant impurities that

it may contain. Information must also be supplied on the physicochemical

properties of the active substance, for example how soluble

it is in water or other solvents, what is its vapour pressure etc and on

methods by which it can be detected and measured, for example in

foodstuffs and water.

2 Potential toxicity in humans

Data on potential toxicity are required for the active substance,

the product as a whole, and also any important metabolites of the

active substance to which humans might be exposed. An important

objective of the toxicological assessment is to establish ‘no adverse

effect levels’ (NOAELs) for any ill-effects that might occur. A NOAEL

is the highest dose in an investigation that does not cause ill-effects.

Specific data on effects in humans is not usually available, particularly

for new active substances. However data are considered on a range

of mammalian species in studies that consider effects that might

occur over an entire lifetime and over several generations.

On the basis of these data, a decision is made as to whether

the product requires labelling as a hazard (eg irritant, harmful,

toxic) in accordance with standard international requirements.

Reference doses are also defined for use in the risk assessments.

These reference doses are carefully derived from the NOAELs of

studies relevant to the type of exposure expected, and always

include an assessment factor to take account of the fact the

studies are in animals and not in humans. Internationally these

are usually set to provide a margin of at least 100 on the key

NOAEL, assuming that average humans are at least 10 times more

sensitive than animals and that particularly sensitive humans are

up to 10 times more sensitive still. Data available from medicines

where there are comparable data available on both humans

and other mammals suggests that this is more than adequate to

take account of these uncertainties as differences in sensitivity are

more usually less than 10 in reality. The size of the assessment factor

can be increased if considered necessary due to either greater

than usual uncertainty in the data package or specific critical

irreversible effects seen in the studies.

The reference doses set are:

Acceptable daily intake (ADI)

This is the amount of a chemical which can be consumed every day

for a lifetime in the practical certainty, on the basis of all known facts,

that no harm will result. It is expressed in milligrams of the chemical per

kilogram bodyweight of the consumer.

Acute reference dose (ARfD)

The definition of the ARfD is similar to that of the ADI, but it relates to the

amount of a chemical that can be taken in at one meal or on one day.

Acceptable operator exposure level (AOEL)

This is intended to define a level of daily exposure that would not

cause adverse effects in operators who work with a pesticide regularly

over a period of days, weeks or months.

3 Dietary intake

One of the ways humans might be exposed to a pesticide is through

its presence as a residue in food. An obvious route of exposure is

residues in food from the treated crop, but residues may also occur

in other foods by indirect routes. For example, they might arise in the

meat, milk or eggs of animals that have been fed on a treated crop,

or from crops grown subsequently to a treated crop if the pesticide is

particularly long-lasting in the environment.

Furthermore, the particular product that is being evaluated

may not be the only source of the pesticide in the diet. The same

chemical may also be a constituent of other products that are

already on the market in the UK or in other countries from which

we import food.

In assessing the risks from residues of a pesticide in foods,

therefore, it is necessary to identify and take account of all

foodstuffs in which significant residues might occur, including those

resulting from the use of other products that contain the same

active substance.

To check whether the proposed use of a pesticide might cause

unacceptable long-term dietary exposures, an estimate is made

of the maximum intake that an individual would be expected to

incur over a prolonged period. This is based on the distribution of

measured residues of the pesticide in foods derived (directly or

indirectly) from treated crops, and data on the national patterns

of consumption for different foods from official surveys, as now

commissioned by the Food Standards Agency. These surveys

provide specific data on both special diets and variations in diet

with age.

The long-term dietary exposure to a pesticide, calculated in

this way, is compared with the acceptable daily intake (ADI). If

the ADI is exceeded, the proposed use of the pesticide will not be

acceptable. The effect of any over-estimation of potential dietary

intakes is to err on the side of safety.

Separate calculations are carried out for dietary exposures in

infants and children, and other consumer groups, to check that

the exposure will be acceptable. Also, if the pesticide has toxic

effects that could arise from a single dose, an estimate is made of

the maximum dietary exposure that could occur in a single day

or from a large portion of that food and this is compared with the

acute reference dose (ARfD). If the ARfD is exceeded, again the

proposed use will be unacceptable.

Finally, if the use of a pesticide produces significant

concentrations of toxic metabolites in food (ie substances formed

by its chemical degradation in plants or animals), the acceptability

of exposure to each of these metabolites is also assessed.

4 Exposures to operators, other workers, bystanders and residents

The other circumstance in which human exposure to pesticides

commonly occurs is in the course of their application or through

contact with crops or other materials that have been treated with

them. For example, an operator might be exposed when mixing or

applying a pesticide; a passer-by or neighbour might be exposed

inadvertently to droplets that drift when a pesticide is being sprayed;

and a worker harvesting a crop that has been treated might handle

foliage that is coated with residues of a pesticide.

Estimating the profile of exposure in operators, other workers

and bystanders is complex and must take into account many

factors. These include:

· the physical form of the pesticide (eg liquid or granules);

· the way in which it is used (eg sprayed with a vehicle-mounted

· boom sprayer or painted with a brush);

· the circumstances in which exposure occurs (eg during mixing

· and application or through contact with a treated surface);

· the use of any personal protective equipment such as gloves or

· a face mask;

· the extent to which the pesticide penetrates the skin;

· patterns of use (including frequency and duration).

The highest exposures in this group are experienced by operators

(people actually applying the pesticide). Sometimes, acceptable

operator exposure (ie exposure at or below the AOEL) can only be

achieved through the use of personal protective equipment such

as gloves, coveralls and face-masks. This may be satisfactory for

professional operators but amateurs cannot always be expected to

have the knowledge that is required to select and use the appropriate

forms of protective equipment. Therefore, amateur uses of pesticides

are not generally authorised where exposures would be acceptable

only with the use of specialised personal protective equipment.

It is important to note, however, that exposure can be controlled

by means other than protective clothing; for example, use of suitable

packaging for products can reduce the exposure of users.

Authorisations are not allowed if estimated exposure of bystanders,

neighbours or workers handling the treated crop is above the

AOEL (and of course it is always assumed these people do not use

protective equipment).

5 Environmental fate and behaviour

In order to assess the potential impact of a pesticide on the

environment, it is necessary to establish what happens to it once it

has been applied – where it gets to; how fast it is degraded and by

what mechanisms; and whether any of its degradation products

might occur at levels sufficient to pose a risk. In particular, information

is needed about the concentrations of the pesticide and any relevant

breakdown products that will occur in soil, water and air, and the

persistence of such pollution.

Predicted environmental concentrations (PECs) are derived,

and are used to assess:

· exposure of non-target species in soil and water;

· possible contamination of groundwater;

· the potential for effects on, or residues in, following crops.

The distribution and breakdown of pesticides in the environment

depends on many factors including the physical and chemical

properties of the pesticide, the climatic conditions following use and

the pattern of usage.

The rate of breakdown of a pesticide is usually summarised by

a half-life value, which represents the time it takes for half of the

pesticide to degrade. The ease with which a pesticide can be

washed out of the soil is usually termed its mobility and a general

impression of this can be gained from a Koc value (organic

carbon sorption coefficient), which gives a measure of how well

the pesticide adsorbs (sticks) to soil.

The mobility and degradation of a specific pesticide can

vary in different soils and can also be influenced by rainfall and


The application rate, frequency of application and overall

pattern of usage can all affect the concentrations of the pesticide

present in the environment, and must be taken into account.

6 Ecotoxicology

The other major determinant of a pesticide’s environmental impact is

its toxicity to wildlife.

The environmental risk assessment focuses upon possible effects

of the pesticide on a range of non-target organisms including:

birds, wild mammals, fish, aquatic invertebrates and plants, insects

(including bees) and other non-target arthropods, earthworms and

soil micro-organisms and non-target plant species.

Acceptable exposure is determined in line with the relevant EU

guidance. For many species this involves comparison of the dose

causing no effects in experiments with the relevant predicted

environmental concentration to form a toxicity:exposure ratio.

If the risk assessment suggests the exposure will cause an

unacceptable risk, a range of possible measures can be

considered to reduce the exposure. One example of such a

‘risk mitigation measure’ is a no-spray buffer zone around water

courses to reduce the amount of spray that might drift onto

surface water. If practical risk mitigation measures cannot be

devised, the product will not be authorised.

7 Efficacy and risk to following crops

Consideration of product efficacy is an integral part of the risk

assessment process. Authorisation of a pesticide is only recommended if

there are discernible benefits from the application of that pesticide.

Data must be available to demonstrate the efficacy of the pesticide

against target organisms when it is used in accordance with the label

instructions. Data are also required to demonstrate that the dose

recommended is the minimum necessary to achieve the desired effect.

In addition, the application of pesticides (especially herbicides)

to a crop may pose a risk to the crop itself or to immediately

adjacent or following crops. Studies are required to examine this.

Like resistance to medicines, resistance to pesticides is also

a widespread problem that limits the effectiveness of many

pesticides and reduces the options for controlling a range of target

organisms. The risk of resistance development is considered for

each pesticide. Where there is evidence or information to suggest

that the development of resistance is likely, a management

strategy designed to minimise the likelihood of resistance or cross resistance

developing in target species is required.

The role of the ACP

A draft evaluation covering all of these aspects is prepared by CRD.

They then pass this to other government departments and to the ACP

for specific advice on the evaluation and whether a product containing

the new active substance can be considered for authorisation in the UK.

The ACP consider these evaluations in great detail, and often require

further studies to clarify aspects of the evaluation. Some examples of this

work are outlined in the ACP’s annual reports. Only when the ACP are

content the product can be used without unacceptable risks do they

advise ministers an authorisation can be granted.

Ministers take note of the ACP’s advice, and only once all

government departments are in agreement that authorisation is

acceptable can an authorisation be issued for the agreed use in

the UK.

Subsequent requests for authorisations of products containing

an approved active substance might require new data in only some of

the seven areas above, but all changes, including administrative

changes such as a change in the name of the company holding

the authorisation, or additions to the crops treated must be specifically


How are authorisations kept up to date?

All pesticides are subject to review at any time if data come to

light that suggest that the risk assessments need significant revision,

and there is a regular review programme in Europe to ensure that

all data are kept up to date and that information is generated to

meet new requirements that apply as scientific knowledge and

understanding increases.

Changes to data requirements occur as scientific knowledge and understanding develops. These are usually updated at the routine review rather than each new data requirement being applied straight away across all currently authorised products. This helps to ensure the work load is more evenly spread, both in the laboratories generating the data, and in the regulatory processes.

Impact of changing EU legislation

During 2009 new EU legislation on pesticides was agreed. The

Sustainable Use Directive (2009/128/EC) sets out a number of ways

in which aspects of pesticide use may be managed in future. A

new Plant Protection Products Regulation (EC 1107/2009) was

also agreed. This has replaced Directive 91/414/EEC. The

Regulation introduces some new aspects to pesticide regulation in

the UK. Examples of these include additional restrictions relating to

‘hazardous’ substances, requirements to consider the substitution

of more hazardous products with less hazardous ones, and a more

collaborative approach to pesticide regulation by introducing the

idea of ‘zonal’ approvals involving groups of member states.

Annex 3

The ACP and its environmental panel has reviewed both the risk assessment approach and the emerging data regularly since 2008 as follows:

Environmental Panel reports.

1) Environmental panel 103 (Oct 2008) notified of ‘restrictions on the use of neonicotinoids pesticides in Germany, Italy and Slovenia’

2) Environmental panel 104 (April 2009) a general update on honeybees outlined R&D responses to concerns about neonicotinoids and possible exposure via guttation and dust created at seed drilling. A new EPPO risk assessment scheme for systemic pesticides was considered.

3) Environmental panel 105 (Oct 2009) update on general EU view on risk to bees from guttation. CRD indicated it was reviewing the Buglife report.

4) Environmental Panel 106 (March 2010) ACP had referred specific questions on the buglife report

5) Environmental Panel 107 (Oct 2010) consideration of issues raised by ACP from the buglife report; new EPPO risk assessment scheme for systemic pesticide; R&D on Guttation; WIIS data on bees; USA data on pesticide residues in beehives.

6) Environmental panel 108 (Feb 2011) panel views on the buglife report to go to ACP; SETAC workshop and OECD bees initiative;

7) Environmental panel 111 (Oct 2012) bees update and papers to consider.

(Notes from these meetings not yet on the web because minutes for 108 were only agreed at the Oct 2012 meeting due to a special meeting focusing on aquatic mesocosms that not all members attended and cancellation of a panel meeting. However the buglife report and papers were also considered at the ACP, so the overall view of the ACP is already published.)


Environmental panel activity is reported back to the ACP. Specific links given here are to additional discussion at the ACP only rather than to each report from the panel.

ACP Links given for individual meetings are to detailed records but shorter minutes drafted to be more accessible to lay readers in line with the Code of Practice for Scientific Advisory Committees are also available here:

1) Meeting 337 (May 2009) Section 16.1 The investigation of the German incident; guttation droplets as a route of exposure for other non-target arthropods; tiered approach to risk assessment for bees; decline in pollinating insects and R&D commissioned.

2) Meeting 340: ACP notified that research on guttation as a potential route of exposure had been commissioned section 9.2

3) Meeting 341 (January 2010) section14. The ACP written response to the buglife report that had been delivered between meetings was referred to the environmental panel for consideration of the additional points raised by the ACP response.

4) Meeting 350 (July 2011) section 10 report from the environmental panel on the further work on non-target arthropods they had taken forward following the buglife report

5) Annual open meeting 2011 discussion on bees formed one of the workshop streams. Conclusions were sent to EFSA.

6) Meeting 355 (May 2012) section 6 discussion of the current concerns about potential risk to bees and consideration of published research.

7) Meeting 356 (July 2012) section 6 Further consideration of data, questions raised by Defra SAC and work underway in the UK and by EFSA. Advice provided for Ministers following this meeting.

8) Meeting 357 (Sept 2012) record not yet published as confirmed at the November meeting. Latest published studies provided.

9) Meeting 358 (November 2012) record not yet drafted. Further published research considered and further advice provided.

Annex 4


Overall, the ACP were agreed that the current risk assessments are secure and have concluded that there is no justification to take regulatory action at present. Furthermore, there is no evidence as yet of neonicotinoid impacts on bees in the UK. However, the ACP will consider any new information as it arises and keep the situation under close review. An explanation of the work leading to this advice is set out below.

1. The ACP has examined in detail the recent publications in the scientific literature. They identified a number of points at a first discussion of this topic at the May 2012 meeting which have now been followed up.

2. Members have carefully reconsidered the data (including an examination of the raw data) supporting the current authorisations for thiomethoxam products in the light of findings from recent published data (specifically the paper by Henry et al) and EFSA discussions. The field studies submitted by the applicants are fully compliant with current regulatory guidance and additionally cover some aspects not required by the current guidance (e.g. over-wintering). In line with current guidance the regulatory studies were not designed with detailed statistical analysis in mind, and their power to detect statistically significant changes is not established. Also, they would not show some of the specific sub-lethal effects suggested by academic studies, such as disorientation over distances. However hives exposed to treated crops did not show any gross effects on a wide range of important endpoints when compared to control hives exposed to untreated crops.

3. While noting there were some questions concerning aspects of the two published studies (by Henry et al and Whitehorn et al), the ACP cannot discount their findings. The Committee believe these studies provide interesting information that should be considered in the development of future regulatory guidance. Some further research is merited in the light of these papers and others to clarify the findings and their relevance to the UK field situation. The ACP is pleased to note that relevant work is already underway.

4. This further work will need time to be completed. In particular the ACP is aware that the study on bumble bees (Defra project PS 2371) is currently in its field phase and it is expected results will be reported in March 2013. The ACP has asked for preliminary information to be made available as soon as possible following the field phase this autumn/winter. The study examining residues in honey bees (Defra project PS2370) to assist in the interpretation of the relationship between pesticides residues and disease in bees is also expected to report in March 2013. A preliminary examination of bee health statistics following the introduction of the neonicotinoids is expected to become available later this summer. Finally the EFSA work re-evaluating all of the neonicotinoid insecticides in the light of the latest research and the development of the revised guidance on assessing risk to bees are both due by the end of this year. The ACP will keep this work and its potential impact on authorisations under review

5. The ACP also identified a number of other possible areas for research into the possible impacts of neonicotinoid insecticides. These include some work on bee toxicokinetics to examine factors related to dose and exposure period, a true field study looking at disorientation (while recognising the very real practical difficulties might make this impossible to do). The ACP also asked their Environmental Panel to look at work on guttation as a potential source of exposure to other non-target arthropods.

6. Although the ACP has considered thiamethoxam in detail, the Committee agreed that the conclusions reached can be applied broadly to the authorisations of other neonicotinoid insecticides because:

· The acute toxicity of thiamethoxam, clothianidin and imidacloprid are all of a similar order of magnitude, with similar extent of use. Acetamiprid and thiacloprid are significantly less acutely toxic and are used on a significantly smaller area.

· The chemical properties of all of the neonicotinoid insecticides are very similar and the mode of insecticidal action is identical for them all.

Annex 5

Insecticide active substances: Bee toxicity data

Non-neonic otinoid s on Oilseed Rape (OSR)





acute oral µg/bee

acute contact µg/bee

other data





tunnel and field




cage and field test




NTA field study considering recovery from effects




field tunnel and cage studies. Repellent effect

Lambda cyhalothrin



field study repellent effect. Short term foraging suppressant




tent and tunnel tests. Formulated product lower tox




cage field and tunnel; repellent, early mortality and no accumulation of reserves but not impact on brood





field studies





cage test











acute oral µg/bee

acute contact µg/bee

other data

Neonic otinoid s on OSR







tunnel and extended lab

Clothianidin *



field studies




cage tests and field tests




tent and tunnel tests




semi-field and field tests

*Clothianidin data presented here are taken from the EU evaluation and there is a slight difference in values compared to the values originally considered by the ACP in the UK evaluation. UK values were acute oral 24 hour LD50 0.00394 µg/bee and acute contact 24hour LD50 0.04697µg/bee.

N.B. the higher the toxicity to bees, the lower the 'µg/bee' figure

'Oral' is toxicity that occurs following ingestion of the pesticide and is particularly relevant when considering potential exposures via food and drink for example.

'Contact' is measured following application directly to the back of a bee and is particularly relevant when considering potential exposures such as from spray drift for example.

Annex 6

Detailed neonicotinoid usage information

1. Arable crops

Around 5 million hectares of crops received a seed treatment overall, which is similar to the foliar insecticide treatment area. All figures used are area grown and area treated as a percentage of the area grown. Information on the potential yield losses for cereals and OSR have been taken from HGCA fact sheet ‘Pest management in cereals and oilseed rape’, and ‘Controlling aphids and virus diseases in cereals and oilseed rape’. Supplementary information was also taken from the HGCA research review ‘Pesticide availability for cereals and oilseed rape following revision of Directive 91/414: effects of losses and new research priorities’.

1.1 Wheatapproximately 2 million ha grown

Approximately 2 million ha of wheat is grown, 96% of which received a seed treatment, with 4% remaining untreated. (The usage data does not separate spring wheat from winter wheat). Approximately 36% of the crop grown from home-saved seed. The most common seed treatments highlighted in the usage survey report are:

24% received prothioconazole (fungicide)

22% received a neonic/fungicide mix treatment (Clothianidin/prothioconazole)

13% prochloraz (fungicide)

12% silthiofam (fungicide)

8% Fluoxastrobin/prothioconazole (fungicides)

5% clothianidin

3.4% of seed was treated with imidacloprid (2008 data)

30% of the crop was grown from seed treated with a neonicotinoid. Neonicotinoid seed treatments are used to:

a) Control pests such as wireworm and slugs, to assist crop establishment and

b) for the control of aphids in autumn sowings, to reduce/control the potential spread of BYDV (grain aphid and bird cherry-oat aphid). Losses from BYDV may be up to 2.5 t/ha when conditions favour aphid population development. The use of seed treatments provides around 6 weeks protection and reduces the subsequent number (or need) for follow up foliar sprays (currently only pyrethroids available). The number of foliar sprays will depend on how mild the autumn/winter conditions are. NB the pyrethroid tefluthrin is also approved for this use, but was not used in sufficient numbers to be reported in the usage survey. (Treatment for spring sown crops is ineffective because the crop is growing quickly at this point). Cultural control methods are important to reduce the ability for ‘green bridge’ transmission (aphid movement) through the crop.

Neonicotinoid foliar sprays did not appear to be a major component of foliar insecticides used in wheat in the 2010 report. Although some crops received a treatment with acetamiprid or thiacloprid it is not possible to report the area treated. In 2008, 0.1% of wheat received a foliar treatment of thiacloprid. NB the foliar approved use is for a ‘reduction in orange blossom midge’. Neonicotinoids would not be the product of choice as, for example, chlorpyrifos is more effective

1.2 Barleywinter (382,531 ha grown) and spring (538,632 ha grown)

Total – 921,163 ha

As described above, seed treatments are used for BYDV control, which is particularly important in barley where it is considered the major disease. Evidence suggests yield losses in winter barley could be 2% (HGCA review).

No neonicotinoid seed treatments listed is listed in the main body of the 2010 survey report, however more complete data available in the report shows 7.4% of winter barley receiving a seed treatment of Clothianidin (either as a straight or in mixture with a fungicide) and less than 1% for spring barley.

Other survey data from 2008 shows 4.8% of winter barley receiving a seed treatment of Clothianidin and 3.7% of winter barley receiving a seed treatment of imidacloprid.

Neonicotinoid sprays do not appear to be a major component of foliar insecticides according to the survey data. (Again they may not be the product of choice).

1.3 Oats – 228,730 ha grown

36% received prothioconazole fungicide

26% - prochloraz/triticonazole fungicide

14% - Clothianidin/prothioconazole neonic insecticide/fungicide

8% fludioxonil

4% - Clothianidin neonic insecticide

A total of 18% of oats received a neonic seed treatment.

1.4 Oilseed Rape – 641, 562 ha grown (97% of which is winter sown)

Less than 1% untreated

22% grown from home-saved seed

Seed treatments

37% received fludioxonil/metalaxyl-M/thiamethoxam

21% - Beta-cyfluthrin/imidacloprid

18% - Beta-cyfluthrin/Clothianidin

16% - prochloraz/thiram

8% - thiram

A total of 76% of oilseed rape received a neonicotinoid seed treatment

Neonicotinoid seed treatments are used to assist in crop establishment and again for the control of Myzus persicae. Seed treatments provide protection for 4-6 weeks, follow up foliar (pyrethroid) sprays may be necessary. The main impact is again as a virus vector of turnip yellows virus in autumn, with yield decreases of 30% in the most susceptible autumn sown seedlings.

Neonicotinoid sprays were not listed in the 2010 report and the 2008 data showed 1% of the OSR area receiving treatment with thiacloprid. However, the approveduse is against pollen beetle – where pyrethroids are also approved and would be product of choice because cheaper. Where pyrethroid resistance has developed then thiacloprid or acetamiprid may be used. More recently flonicamid and pymetrozine have also been approved to give other MOA options where pyrethroid resistance is prevalent. As part of resistance management and to slow down its occurrence, there has been various research refining the pollen beetle thresholds and providing advice emphasising the need only to spray when the threshold is reached. (There was evidence that a significant amount of pyrethroid use occurred even in years when the thresholds weren’t reached.

More recently, thiacloprid has also been approved as a foliar spray against Myzus, so use may increase in future years. This is seen as in response to an increasing problem of Myzus, which historically has not reached levels justifying treatment.

For any foliar use, the UK has implemented a statutory restriction of only 1 foliar spray of any neonicotinoid containing product per crop, so usage will always be limited.

HGCA review notes that pests of OSR can have a greater impact on yields than cereal pests. Actual figures on yield losses (rather than from experimental work) were stated to be limited, but levels around 1-6% losses were estimated.

1.5 Linseed – 43, 838 ha grown

8% grown from home-saved seed

50% - prochloraz

50% - Beta-cyfluthrin/imidacloprid

A total of 50% of linseed received a neonic seed treatment according to the 2010 report.

In 2008, 77% of linseed received a seed treatment of imidacloprid.

1.6 Seed Potato – 17, 440 ha grown

It is considered that this should be more accurately defined as potatoes grown for seed as opposed to a seed treatment for potato tubers.

5% of the crop was grown from home-saved seed.

According to the main body of the 2010 report, 41% of the seed potato area received a neonic foliar spray (thiacloprid).

In 2008, 3% of the potato seed crop received a foliar treatment with acetamiprid and 96% with thiacloprid and 13.4% with thiamethoxam.

Foliar sprays are a critical use for potatoes grown for seed because of the need to keep the seed potatoes free of virus – the main transmitter again being Myzus persicae. Multiple foliar applications will be made over the course of the season. There are four MOA available as foliar sprays: pyrethroids, neoncotinoids, pymetrozine and flonicamid. However, producers of seed potatoes use pyrethroids as the product of choice because of its perceived repellent effects. Virus transmission can take place within minutes of aphids starting to feed, so this is seen as a valuable trait. There is significant widespread resistance to pyrethroids, so alternation with other MOA is essential. From the usage data, neonicotinoids are the other principle foliar spray that will be used as part of the overall treatment programme. CRD imposed a maximum of two foliar applications on potato grown for seed,

Foliar applications are also made on ware potatoes, although aphid populations rarely reach significantly damaging levels through direct feeding. Typically only 2 applications may be required, and for this reason CRD imposed a restriction of 1 foliar application on ware potatoes.

Figures taken from the British Potato Council Research report (2009) ‘Pesticide availability for potatoes following revision of Directive 91/414/EEC: Impact assessments and identification of research priorities’ estimated losses (£Million) of 3.2-7.9 for fresh and processed potatoes, and 16.6 for seed potatoes if Myzus persicae was untreated.

1.7 Sugar beet – 118,494 ha grown

No home-saved seed due to the structure of the sugar beet market.

33% received hymexazol

33% thiram

13% thiamethoxam

12% Tefluthrin

7% Beta-cyfluthrin/Clothianidin

A total of 20% of sugar beet seed received a neonicotinoid seed treatment according to the 2010 report.

According to the 2008 data, 53% of the sugar beet received a seed treatment of Clothianidin, 7% with a seed treatment of imidacloprid and 11 % with a seed treatment of thiamethoxam.. This makes a total of 71% of sugar beet seed received a neonicotinoid seed treatment according to the 2008 data.

(According to BBRO Brooms barn, over 70% seed was neonic treated in 2012).

Neonicotinoids are particularly important for crop establishment, by controlling a range of soil pests, and then providing protection against aphids – particularly again Myzus, because it transmits virus yellows. There is no viable foliar option – the only approved product is pirimicarb and resistance to this is widespread (to the point where approval holder no longer recommends it). No neonicotinoid foliar sprays are approved on sugar beet – however twice in the last 5 years CRD has issued an emergency approval for the foliar use of thiacloprid to control aphids where (for various environmental reasons) the neonicotinoid seed treatments did not provide the usual length of control. There are pyrethroid-only seed treatments, but these do not include a claim for aphid control (only soil pests), and it would appear from the usage data to not be widely used.

The British Beet Research Organisation (BBRO) website puts usage of neonicotinoid seed treatments at over 90%, and notes that their effectiveness has reduced the need for further treatments. However, it was also noted that reliance on neonicotinoids alone, combined with the exposure Myzus receives on other crops, means that resistance risk is developing.

1.8 Maize

Used as a seed treatment for soil pests to aid crop establishment and subsequent frit fly infestations. Data from 2009 PUS survey indicate 5% was treated with clothianidin, 2% with imidacloprid, and 0.3% with thiamethoxam – a total of 7.3% ha. Around 160,360 ha were grown.

2. Horticultural uses

Neonicotinoids are also authorised in a wide range of horticultural crops either through on-label uses or off-label (EAMU/SOLA), across vegetable, fruit and ornamental uses. They are used as foliar sprays predominantly, although there are soil incorporation treatments (ornamentals). Whilst the ha treated is small compared to arable crops, they can still represent very important chemical control options, particularly in niche crops. Data from the PUS (2011) and more detailed information on uses and alternatives is available from the ADAS report (funded by DEFRA) on ‘Impact of changing pesticide availability on horticulture’ have been used to illustrate some key uses:

114% (i.e > 1 spray) of protected chrysanthemums (2007) and 61% of iceberg lettuce (2007) being treated with acetamiprid;

96% of mustard (2007) receiving a seed treatment of imidacloprid;

94% of nut trees (2008) receiving a foliar application of thiacloprid

Brassicas are also a major use – for aphid control - only 2007 data available for thiacloprid, but for some of these crops around 50% will have been treated. (around 26,000 ha Brassicas in 2008). This figure is likely to have risen since then, again due to resistance issues with pyrethroids and pirimicarb. Alternatives on Brassicas are pymetrozine, spirotetremat, and indoxacarb.

Carrots: around 12,000 ha grown, and 1/3 treated with thiacloprid for aphids (willow-carrot). Pirimicarb is available as an alternative.

Lettuce: 5877 ha grown, around 1200 treated with thiamethoxam, thiacloprid or acetamiprid for aphid control, including the currant-lettuce aphid. Alternatives to which there is no resistance are spirotetremat and pymetrozine.

Apple, plum: thiacloprid and flonicamid are used for aphid control.

Blackcurrant: sawfly - thiacloprid or chlorpyrifos

Raspberry – raspberry beetle, capsids, sawfly – thiacloprid and a range of other actives

Strawberry – capsids are controlled by thiacloprid or bifenthrin, biological control agents are an important component of IPM.

Hardy nursery stock – thiacloprid can be used for aphid control, but where IPM practised other actives are used with a shorter persistence to avoid impacts on predators e.g. pirimicarb, pymetrozine, permethrins. It is more widely used for thrips control (larvae), particularly because of resistance in alternatives such as pyrethroids, abamectin and spinosad.

Protected ornamentals – thiacloprid is used for control of aphids, with pymetrozine and pyrethroids as alternatives. It is also used for thrip control, along with spinosad and abamectin.

21 November 2012

[1] Maximum Residue Level (MRL): The maximum concentration of a pesticide residue (expressed as mg/kg)

[1] legally permitted in or on food commodities and animal feeds. MRLs are based on good agricultural practice

[1] data and residues in foods derived from commodities that comply with the respective MRLs are intended to be

[1] toxicologically acceptable.

[2] LD50 the theoretical lethal dose for 50 per cent of a group of animals


Prepared 3rd December 2012