VIII SIMPOSIO INTERNAZIONALE ICPBR

HAZARDS OF PESTICIDES TO BEES

Bologna, 4-6 Settembre 2002

Metodologie dei test e studi sugli effetti dei pesticidi sulle api

Honey bee brood ring-test in 2002: method for the assessment of side effects of plant protection products on the honey bee (Apis mellifera L.) brood under semi-field conditions (tunnel test)

Andrea Schur (1), Ingo Tornier (1), Dietrich Brasse (2), Werner Mühlen (3), Werner von der Ohe (4) , Klaus Wallner (5) and Martina Wehling (4)

(1) GAB Biotechnologie GmbH, Eutinger Strasse 24, D-75223 Niefern-Öschelbronn, Germany. E-mail: andrea.schur@gab-biotech.de
(2) Biologische Bundesanstalt (BBA), Messeweg 11/12, D-38104 Braunschweig, Germany
(3) Landwirtschaftskammer Westfalen-Lippe, Arbeitsbereich Bienenkunde, Nevinghoff 40, D-48147 Münster, Germany
(4) Niedersächsisches Landesinsitut für Bienenkunde, Wehlstrasse 4a, D-29221 Celle, Germany
(5) Universität Hohenheim, Landesanstalt für Bienenkunde, August-von-Hartmann Strasse 13, D-70593 Stuttgart, Germany

Based on the presented test methods in the past to evaluate possible side-effects of plant protection products on the honey bee brood and the recent OEPP/EPPO No.170 guideline, the "Arbeitsgemeinschaft Bienenschutz" developed a new test method in the semi-field. According to that method semi-field trials were carried out as a ring-test at different locations in Germany in 2002 to obtain as many data as possible for further discussions.

Each trial consisted of 2 treatments; i.e. the reference substance Insegar 25 WG, which is known as an IGR and the water treated control treatment. Separate tunnel tents (at least 40 m2 crop area per tunnel) with flowering Phacelia (Phacelia tanacetifolia Benth.) were used for the different treatments. The crop was sprayed in both treatments on the same day during bee-flight activity of the bees. The effect of the reference substance Insegar 25 WG was examined on small bee colonies ("Mini-Plus-Beuten") placed in the tents before the application. The bee colonies were exposed to the treated crop for 7 days.

Special attention was turned on the assessments of the condition of the colonies and the development of the bee brood during the trials. The assessments were carried out at least once before the application and four times after the application on fixed dates. The time schedule of the assessment dates was chosen in order to check the bee brood at different expected stages during the development. For the evaluation of the condition of the colonies the strength of the colony, presence of a healthy queen, areas with the pollen and nectar on combs and areas containing eggs, larvae and pupae on combs were assessed. The development of the bee brood was evaluated by using transparent overhead folio to mark single cells on brood combs with its content on different assessment dates during each trial. Additionally the flight intensity in the tunnels and the mortality was checked before as well after the treatment.

For the validation of the test system, the evaluation was done by comparing the results in the reference substance treatment to the water-treated control and furthermore by comparing the pre- and post-application data. For special interests on the honey bee brood development the detailed assessments with transparent overhead folio were evaluated by calculation of brood termination-rates in % and different indices (e. g. egg-index, compensation-index) for Insegar 25 WG in comparison to the water-treated control.