EPPO 170: Honey Bee Field Study – do plant protection products effect honey bee colonies?

Honey bees (Apis mellifera L.) have a very important role in pollinating flowers and orchards. Their honey is used as a food since thousands of years. For these reasons international legislation claims for the protection of honey bees from any possible side-effect of agrochemical applications. A field study on honey bees under realistic conditions of agricultural practice (GAP) is indicated if laboratory studies and semi-field studies cannot sufficiently prove harmlessness of plant protection product applications. A field study allows to assess the impact of plant protection products on honey bee colonies under real agricultural conditions and thus is the final tool to show whether possible effects are acceptable.

Honey Bee Colonies at field site (Phacelia tanacetifolia)

Study Design

Test organisms

Healthy honey bee colonies, bred in normal beekeepers manner, of appropriate size should be produced to guarantee that the colonies are as uniform as possible. The quantity of food stores within the hive at the beginning of a study should be kept at a minimum to ensure larvae being fed by contaminated food.

Test Concentrations

Only formulated products are tested and should normally be applied at the highest field rate intended for the registration of the product in order to produce a worst-case exposure of the bees. A field test include at least a field treated with the plant protection product and an untreated control field (no reference item treatment is used).

Field Sites

The field sites should met the following criteria:

  • At least two field sites (1 test item field and 1 control field)
  • A size of at least 2500 m2 in case of Phacelia tanacetifolia or 1 ha in case of Brassica napus
  • The total number of honey bee colonies should be in relation to the size of the fields
  • The field sites should be seperated in a suitable distance (at least 2 to 3 km)
  • Preferable, no main massive bee attractive crops should be in a radius of 2 km close to the surrounding of the field sites

Course of the test

At least four bee colonies per test group, bred in normal beekeepers manner, will be placed on the edge of the fields a few days prior to the application. The crop should be full flowering with bees actively foraging on the crop. On the day of application, the whole plot is sprayed according to GAP with calibrated field spraying equipment. The control plot remains untreated.

After 7 days of direct exposure of the colonies to the treated crop, the bee colonies are removed from the field sites to an area with no main attractive crops. The full testing period is up to 28 days following the application day.

Optional: Residue analysis

According to regulatory requirements residue studies may be required to determine residue levels in:

  • pollen
  • nectar
  • flowers
  • and/or foraging bees

In order to proove exposure, residue samplings can be incorporated into field studies with additional hives used exclusevily for residue purposes. Bee hives used for residue samplings are not biologically assessed (e.g. mortality, foraging activity, colony assessments, etc.).  Details about the residue samplings are described in the recent study protocol (e.g. timing, amount, etc.).

Endpoints /Parameters

  • Meteorological data
  • Foraging activity: in marked areas of 1 m2 the number of bees are counted during e.g. 10-15s.
  • Mortality: mortality in the hives are assessed by counting dead bees in dead bee traps. In addition, sheets (3 × 1.5 m) can be spread out infront of the bee hives in order to facilitate the collection and counting of dead bees infront of the bee hives.
  • Behavioural abnormalities
  • Condition of the colonies: the state of the adult bee population, the viability of the queen and the area of brood and food is assessed.
  • Optional: Assessment of bee brood development (adaptations according to the OECD guideline no. 75). Please refere to “OECD 75: Honey Bee Brood Test under semi-field conditions”.

Guidelines and Literature

  • OEPP/EPPO guideline No. 170 (4) (OEPP/EPPO, 2010)
  • Optional: adaptations to OECD 75: “Guidance Document on the Honeybee (Apis Mellifera L.) Brood Test under Semi-Field Conditions"
  • AG Bienenschutz (2011)