VIII SIMPOSIO INTERNAZIONALE ICPBR

HAZARDS OF PESTICIDES TO BEES

Bologna, 4-6 Settembre 2002

Apicidi e schemi di monitoraggio

Bee pesticide poisoning incidents in the UK

Mark Fletcher and Libby Barnett

Wildlife Incident & Diagnostic Unit, Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK. E-mail: m.fletcher@csl.gov.uk

Since 1980, the present Scheme has been in operation in the United Kingdom, investigating possible pesticide poisoning of bees. This formalised Scheme was set up after provisional approval allowed the aerial application of oil seed rape with the organophosphate compound, triazophos, that resulted in a large number of incidents involving honeybee mortality. The Scheme enables post-registration surveillance of agricultural and other chemicals to be conducted. With real results from the field the Scheme provides data that can be used to validate and improve any risk assessment processes used in the registration of new or existing products. The Scheme can also be used to enforce existing legislation on pesticide applications or those protecting the environment.

After potential incidents are reported to the Scheme and certain acceptance criteria have been met, a field inquiry is carried out to ascertain the extent and circumstances of the incident where possible. Samples of dead bees are submitted for adult bee disease diagnosis and chemical analyses are performed to detect any potential residues using modern chromatographic techniques.

Over the years, the number of incidents reported to the Scheme has declined from over 100 to about 30 in each year. The main reason for this has been an appreciation of the problem that chemicals can cause to bees when used in the field. The registration process of new products or existing compounds to new uses has resulted in a vigorous assessment of the risk of compounds to bees, giving fewer poisoning incidents arising from the approved use of compounds. Steps have been taken by regulators and manufacturers to alleviate problems that have been found by incident surveillance. A better understanding of the potential problems by farmers and contractors has led to liaisons between them and beekeepers.

Although incidents arising from approved use are reported from time to time, most incidents that have occurred in more recent years usually involve the misuse of a product, by careless, accidental or wilful failure to adhere to the correct practice. Incidents have arisen from spraying crops when in full flower; spraying crops that, although not in flower, have weeds in flower around them; and spraying non-toxic products from tanks that have previously held toxic material and have not been cleaned out properly. Incidents have arisen where control of feral bee colonies by pest control operators have resulted in the treated colonies being robbed and the chemical used then killing the robbing bees. Products used to control wax moth in stored foundation, either approved or not approved for this, have also resulted in incidents, as the compounds have not been allowed to disperse prior to use.

The Scheme acts as a barometer, detecting what has poisoned bees and how this poisoning has come about. It provides valuable information for regulators, agrochemical companies, farmers, beekeepers and the enforcement authorities.