House of Commons - Pollinators and Pesticides - Environmental Audit Committee

Pollinators and Pesticides - Environmental Audit Committee Contents

1 Introduction

Our inquiry

1. In recent years, approximately two thirds of species of wild insect pollinators have experienced population decline in the UK, while managed honeybees have experienced unusually high mortality rates, an impaired ability to pollinate crops, decreased fecundity, increased susceptibility to disease and the loss of hives.[1] Emerging scientific evidence on the possible influence on those trends, which have been replicated across Europe, of neonicotinoid pesticides has driven a discussion about the appropriate response by Governments and regulators.[2] That discussion has resulted in a range of regulatory actions across Europe, where French, German, Italian and Slovenian authorities have variously suspended the use of certain neonicotinoid insecticides on particular crops.[3]

2. Several research studies were published in 2012 on the impact of neonicotinoids on bees, notably Henry et al (A common pesticide decreases foraging success and survival in honeybees), Whitehorn et al (Neonicotinoid pesticide reduces bumblebee colony growth and queen production) and Gill et al (Combined pesticide exposure severely affects individual and colony-level traits in bees). In September 2012, Defra published Neonicotinoid insecticides and bees: The state of the science and the regulatory response, which included its review of the Henry and Whitehorn research. It concluded that those studies did not justify changing the regulations and announced that it would undertake further research itself.

3. In May 2012, the European Food Safety Authority (EFSA) published a Scientific Opinion on the risk assessment of pesticides in relation to bees, which identified a need for a more comprehensive risk assessment for bees and recommended the introduction of a higher level of scrutiny in interpreting field studies on the impact of pesticides. Those higher standards of environmental protection and of scrutiny of field studies are yet to be agreed by EU Member States and are currently out for consultation.[4] The European Commission also tasked EFSA to produce a new risk assessment for neonicotinoids, which was published in January 2013 in the course of our inquiry.

4. Against that background of continuing scientific research on the possible effects of neonicotinoids on pollinators and discussion about the appropriate regulatory response, we decided to undertake an inquiry on what the approach in the UK should be and on how the Government should seek to shape policy making and regulation in the EU. The timing of this inquiry reflects not only the current debate in the UK and Europe—EU Member States voted on a proposal to implement a temporary moratorium on the use of certain neonicotinoids in particular circumstances on 15 March 2013—but seeks to contribute to the ongoing discussion about the relationship between science and politics and the application of the precautionary principle.

5. The relationship between insects and insecticides also relates to a wider recent debate about sustainable food. In our May 2012 Report, Sustainable Food, we highlighted the links between food production research, food production and consumers' options and behaviours, and examined in particular the environmental impacts of producing food, the appropriate role of developing new food production techniques and the role of biotechnology.[5]

6. We took oral evidence from NGOs, scientists, the Advisory Committee on Pesticides (ACP), pesticide manufacturers Bayer CropScience and Syngenta, Defra officials, the Defra Minister Lord de Mauley, EFSA and agronomists. We also took written evidence from a range of people who are concerned about the plight of bees and other pollinators, and about the potential environmental impacts of pesticides on the environment more generally. We are grateful to them all.

7. In our inquiry, we focused primarily on neonicotinoids, rather than other pesticides, and their effects on pollinators rather than other potential environmental impacts. Accordingly, although we took evidence on potential impacts on human health (Annex), these were not a feature of our inquiry. We examined the pesticides approval system (Part 2), risk assessment, risk management and the precautionary principle (Part 3), and what more needs to be done to support pollinators in the UK (Part 4).

Insect pollinator populations

8. Thousands of insect species contribute to pollination in the UK, including bees, hoverflies, butterflies, carrion flies, beetles, midges and moths. The relative contribution of different insect species in providing pollination services has not been systematically assessed in the UK. Several characteristics of bees, such as their size, hairiness and foraging behaviour, suggest that they pollinate flowers more efficiently than other insects. UK bees include the honeybee, about 20 bumblebee species and more than 200 solitary bee species. Honeybees are intensively managed, whereas bumblebees and solitary bees are wild and unmanaged.

9. Honeybees are often cited as the most important crop pollinators, but the role of wild bees is becoming increasingly apparent to researchers. Honeybees are a practical solution to pollinating intensively farmed crops, because they can be reliably managed to be available when crops are in bloom, but wild bees may be more effective on particular crops. In apple orchards, for example, research indicates that 600 solitary bees can pollinate as well as two hives containing 30,000 honeybees.[6] A study of British oilseed rape fields found that bumblebees were twice as abundant as honeybees, and wild bees may also act synergistically with managed bees to increase pollination and crop yield.[7] It is difficult meaningfully to measure the UK's honeybee population, because it is largely a function of the number of hives maintained by beekeepers.[8]

10. Attention has recently been drawn to pollinator health by the unusually high mortality rates of managed honeybees in the USA and Europe.[9] Similar trends in other countries have contributed to claims of a global pollination crisis, although the data are limited for species other than honeybees. The decline in the well-being of honeybees has been linked to a range of factors including pests and diseases such as the Varroa mite, poor nutrition, urbanisation, agricultural intensification, habitat degradation, poor husbandry by beekeepers and climate change, as well as to pesticides and the misapplication of pesticides.[10]

11. In the UK, the overall abundance of wild pollinators has decreased in the countryside since the 1970s, and certain species have declined dramatically.[11] Buglife told us:

As a rule of thumb, two-thirds of the species of pollinator are declining. Where we have the data, that is the situation—two-thirds are declining. So, 66% of larger moth species in the countryside, including things like the Hedge Rustic, are declining. Most of the bumblebees are declining and six species have declined by at least 80% in recent years. Where change is detectable in the data, 66% of hoverflies are declining, 71% of butterfly species are declining.[12]

Similarly, Dr Lynn Dicks of Cambridge University pointed out:

It looks like about two thirds to three quarters of species are declining, and a good proportion of those species are declining by more than 30% every 10 years. So, for moths, two thirds of species are declining and 21% have declined by more than 30% in 10 years and that is of the widespread common species. For butterflies, it is a similar picture: 72% of the species are declining and more than half of them have declined in their distribution.[13]

12. Wild pollinator species conduct 90% of pollination in the UK.[14] Buglife told us that "70 Government scientists are researching the health and populations of honeybees and part of one person is looking at the health of wild bees."[15] Dr Dicks made the same point:

Defra does have a bee unit that has quite a lot of staff, so they are spending quite a bit of money on monitoring bees. It is a very good monitoring scheme; there is quite a lot of scientific investigation into honeybees, and it is only for honeybees almost entirely. So there is money; it is just somebody has decided and continues to decide that we are only interested in looking at honeybees.[16]

Professor Dave Goulson of Stirling University highlighted the limited data that are available to policy makers and regulators on wild bees and other pollinators:

For bumblebees, we don't have numbers, so we can't tell you what the population is or how it's changed in the last 10 years or 100 years. Sadly, all we can do is look at range declines. What we can say is of the 25 UK bumblebee species, two or three—it's a moot point as to whether it's two or three—have gone extinct and probably 10 species have undergone very large range decline.[17]

13. The available evidence indicates that wild insect pollinators, such as hoverflies, moths, midges, butterflies and wild bees, are experiencing serious population declines, but there is insufficient data to be precise about the extent of such declines due to inadequate monitoring. Defra must introduce a national monitoring programme to generate and monitor population data on a broad range of wild insect pollinator species to inform policy making.

Neonicotinoids and UK agriculture

14. The Food and Environment Research Agency (FERA) Pesticide Usage Survey found that the total amount of agricultural land treated with pesticides in 2011 (5,974,000 hectares) was similar to the area treated in 1991 (5,991,000 hectares). Over that period, the total weight of pesticides applied more than halved, falling from 1,024,000 kg to 437,000 kg, due to improvements in the effectiveness of active ingredients and in application technology.[18] That decrease encompassed a significant drop in the use of pesticide sprays (from 965,000 kg in 1991 to 356,000 kg in 2011) and a smaller increase in use of systemic seed treatments (from 58,000 kg to 81,000 kg).[19]

15. The range of active ingredients available to farmers in the EU has decreased significantly in the past 20 years. This decrease was driven by the introduction in 1993 of EU Directive 91/414, which developed the regulatory framework for pesticide registration. The number of active ingredients available for use in the EU fell from some 900 in 2001 to approximately 230 in 2009.[20]

16. Five neonicotinoids are currently approved for professional use in the UK, namely acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam (TMX). Dr James Cresswell of Exeter University told us how those substances fall into two groups:

These five chemicals fall into two groups based on their chemical structure. You have thiamethoxam, imidacloprid and clothianidin in one group. You have acetamiprid and thiacloprid in the other group. That second group are probably one to two orders of magnitude less toxic than the other three, so immediately you cannot put all neonicotinoids under one label on how they will behave. In our lab, even among the three—imidacloprid, thiamethoxam, clothianidin—we are finding small but biologically interesting qualitative differences in how bees respond to those different chemicals. So some generalisation is possible, but in the details not so.[21]

17. Neonicotinoids are widely used in the UK on oilseed rape, cereals, maize, sugar beet and crops grown in glasshouses.[22] Neonicotinoids are often applied as seed treatments, which involves coating seed with a neonicotinoid insecticide in a warehouse. They are systemic, so following seed treatment, the neonicotinoid is absorbed and transported throughout the plant, which improves pest control efficiency and limits the requirement to apply subsequent foliar sprays.

18. FERA records the extent of the use of all pesticides in the UK (Figure 1).[23] The FERA data show the relatively smaller scale of thiacloprid and acetamiprid use compared with imidacloprid, clothianidin and TMX. The ACP told us that "the use of imidacloprid in the UK is declining very rapidly indeed. It is being replaced by another neonic, clothianidin."[24] Bayer CropScience also stated that the application of imidacloprid is declining "very rapidly indeed".[25] The FERA data partially confirm those observations, although imidacloprid was still applied to some 190,000 hectares of crops in 2011.

Figure 1