Q & A

General Questions

1. What is the metaldehyde issue?

2. What is the slug issue?

3. What is best use advice?

4. What is damage issue?

5. What is cost issue?


Specific Questions

1. What is metaldehyde and what is it used for?

Metaldehyde is a selective molluscicide used to control slugs and snails in a wide range of crops. It is applied as an edible bait containing a small amount of active substance. It has been used for slug control for over 50 years, having first been observed in the 1930’s when metaldehyde was used in camping stoves as a fuel.

back to top

2. Is slug control necessary in UK agriculture and horticulture?

Slugs are the largest pest problem in the UK and are reported to account for 70% of all crop pest problems.

back to top

3. What is the problem with metaldehyde and water?

It has been found in minute quantities (i.e. normally less than 5 parts in a billion) in some reservoirs and rivers known as raw surface water. In a few cases the levels have breached the Drinking Water Regulations of 0.1 part in a billion i.e 1 in 1,000,000,000.

back to top

4. Are the metaldehyde levels being found in water dangerous to health?

Since the toxicity of metaldehyde is very low, the levels found in water are not considered to be harmful to human health, but it is important that all parties work together as a matter of urgency to put new guidelines in place to ensure metaldehyde does not enter watercourses.

back to top

5. When was the problem first identified?

Minute quantities of metaldehyde were first detected in raw surface water in 2007 following the introduction of new analytical techniques.

back to top

6. Can it be removed from water?

Current raw water treatment processes are less effective for metaldehyde than for other pesticides. The water industry is working on treatment methodology – the work is ongoing.

back to top

7. How is it getting into water?

New research funded by the Metaldehyde Stewardship Group (MSG) has highlighted that diffuse field losses via field drainage and surface runoff are more significant than previously understood in terms of the possible routes by which metaldehyde is reaching raw water supplies.

back to top

8. What will be done to eliminate the problem?

A stewardship group has been formed with all the main pellet manufacturers. They are working with the water companies and industry bodies such as Voluntary Initiative, Crop Protection Association, Agricultural Industries Confederation, and National Farmers Union to develop stewardship approaches. This will remind all operators that slug pellets are pesticides and reiterate what needs to be done to ensure they do not make contact with watercourses.

back to top

9. What has been done so far?

The Metaldehyde Stewardship Group of companies has been very pro-active since its formation in April 2008. - 50,000 best practice stickers have been produced for farmers to affix to their slug pellet applicators which have been widely distributed at industry events and through distributors as well as being inserted into agricultural press and industry newsletters. - 20,000 Best Practice Advice, 8-page leaflets produced and distributed in Crops magazine as well as circulated wider to the industry - Presentation on the issues and best practice compiled for agronomists - Discussion is taking place on the way forward with formulations - A major water catchment study is being funded to identify how metaldehyde is getting into water - PR activity including: - Farmers Weekly Academy double-page spread feature article - Farmers Weekly Academy on-line training modules on best practice use of slug pellets as well as slug biology and pelleting preparations - Press release announcing formation of MSG and Cereals activity - Article in Crops magazine, August issue - Article in Farmers Guardian, September Arable Focus - Article in ProOperator magazine, September issue

back to top

10. Are slug pellets over used?

In the past, metaldehyde in water has not been a problem. The best practice guidelines promote targeted treatments and the use of trapping to justify applications. Only ‘Approved’ slug pellets should be used.

back to top

11. Are slug pellet applications always justified?

No. Trapping should be used as much as possible to make sure that there are active slug populations in that particular field. Pellets should only be applied when levels reach the thresholds.

back to top

12. Are other methods available to control slugs?

Integrated control is advocated which includes rotation, cultivations, drilling date, drilling depth and seedbed consolidation. There are other methods of control, such as biological control with nematodes, but these are either not suitable for large scale use and/or are not commercially viable. However, with increasing amounts of oilseed rape in the rotation coupled with mild winters and wet summers, the problem of slugs is likely to increase and there will continue to be a need for effective control.

back to top