What is it that has caused this action? The background is that Insect pollinator numbers in general are known to be in long-term decline, and this is currently the subject of intensive research. A linked issue is ‘colony collapse disorder’ (CCD) which has affected many honey bee populations in North America, but has not yet been recorded in the UK. Concerns have been raised that the use of neonicotinoid products may be contributing to pollinator decline by having harmful effects on honey bee and (more recently) bumble bee populations. This is because the systemic nature of the seed treatment products (thiamethoxam, clothianidin and imidacloprid) in particular means that very low doses can pass through the plant and be found in pollen and nectar when crops flower. Bees feeding on flowering crops carry pollen and nectar back to the colony, where the insecticides residues may have subtle effects on brood and queen production; some research has also suggested that foraging bees can become disorientated by low doses of neonicotinoids. The extent to which this may happen in the natural environment against a background of a number of other factors such as Varroa mite infestations that may also affect bee health, is unclear and is the subject of further research . These subtle ‘sub-lethal’ effects need to be distinguished from some acute bee death incidences in Europe in recent years (in Germany and France) which were linked to excessive dust from neonicotinoid seed treatments contaminating flowering plants in field margins during the drilling of maize. This type of situation has not arisen in the UK, and is unlikely to due to different agronomic approaches to maize production here compared with elsewhere in Europe.
The recently published academic research on the effects of neonicotinoids on bees had already raised the question of whether restrictions should be placed on neonicotinoid use in the UK, particularly as some specific restrictions are already in place on neonicotinoid usage in some other European countries, notably France, Germany, Italy and Slovenia, on the basis of similar evidence. These recent studies and the existing evidence have been assessed by the Chemicals Regulation Directorate (CRD) of HSE; bee experts in Defra’s Food and Environment Research Agency (Fera); Defra’s Science Advisory Council; and the independent expert Advisory Committee on Pesticides (ACP). Parallel work has also been done by the European Food Safety Authority (EFSA) who have recently issued reports on thiamethoxam, clothianidin and imidacloprid. In September, Defra issued a document which summarised their position. In essence, the decision was that although there was sufficient evidence to show that bees could be exposed to low doses of neonicotinoids, there was no evidence, as yet, of actual field effects. However, further studies are underway to try and close that knowledge gap, and early analyses of these data will be reviewed by the regulatory authorities as a matter of urgency. In the meantime, CRD have made initial soundings with the industry to try and ascertain what the impact of any restrictions on neonicotinoid uses might be on UK agriculture and horticulture.
The neonicotinoid insecticide debate
Neonicotinoid insecticides account for about 20% of overall insecticide usage in the UK. These can either be applied as seed treatments (imidacloprid, thiamethoxam, clothianidin) or as foliar sprays (thiacloprid, acetamiprid). By far the majority of use (in terms of area treated) is on cereals and oilseed rape as seed treatments (currently over 90% of the neonicotinoid usage). There is also some seed treatment usage on crops such as sugar beet and linseed, and some foliar usage on arable crops such as oilseed rape and potato. Horticultural uses – mainly accounted for by sprays of thiacloprid, and some specialist soil applications of imidacloprid to container-grown ornamentals and hops – account for <6% of the total neonicotinoid treated area. However, these products can be vital for certain horticultural crops.The issues surrounding neonicotinoid usage are of general public concern, and have been picked up by the Environmental Audit Committee, a Parliamentary Select Committee that considers the development and impact of government policies related to the environment. This enquiry into ‘Insects and Insecticides’ is on-going, and has taken evidence from many interested parties, including environmental groups, agrochemical companies, academics, the NFU, ACP, CRD and Defra ministers.
HDC maintains a careful watching brief on this issue as neonicotinoids are a key group of insecticides for horticultural producers. It is not the role of HDC to lobby for or against the use of neonicotinoids but to provide factual and technical information to others, including the NFU and CRD, to help ensure that the policy debate is correctly informed about the needs of the horticultural industry.
Source: HDC
