EAR expert comment: OECD Test Guideline No. 254
EAR expert comment on the Test No. 254: Mason bees (Osmia sp.), Acute Contact Toxicity Test
Here, Regulatory Expert Lisa Hanslik comments on OECD Test Guideline No. 254…
The OECD Test Guideline No. 254, adopted on June 25, 2025, provides a standardized laboratory method to assess the acute contact toxicity of chemicals on adult solitary bees, specifically Osmia bicornis and Osmia cornuta.
The OECD 254 guideline is not yet explicitly listed as a data requirement in Regulation 284/2013 for plant protection products in accordance with Regulation (EC) No 1107/2009. However, according to EAR experience some EU member states consider that the Regulation 284 and 283 refer to generic “bees” (including non-Apis bees such as bumble bees and solitary bees) and therefore require testing also on non-Apis species especially since approved guidelines are available (OECD 246/247, 254).
Test Organisms
The test focuses on adult female solitary bees, specifically Osmia bicornis and Osmia cornuta. Bees should be newly emerged, healthy, and of similar size to ensure consistent results. They are selected from cocoons harvested the previous year and stored under controlled conditions.
Test Procedure
Bees are exposed to the test chemical by applying a small volume (1-3 µL) directly to the dorsal side of the thorax. The test lasts for 48 hours, with possible extensions to 72 or 96 hours if necessary. Observations on mortality are made after 4h of test item application, as well as after 24 h and 48 h.
Analytical Verification
Aliquots of the lowest and highest test concentrations, and the control, are collected and stored at or below -18°C for verification. If the test chemical concentrations are within ±20% of the nominal values, results are based on nominal concentrations. Otherwise, results are based on measured values.
Eurofins Agroscience Services has extensive experience with solitary bees, with our expert laboratory teams closely involved in the development of the OECD 254 guideline.
Trials with solitary bees need to be planned well in advance, due to the long-term development period of the bees (cocoons will be ordered during the autumn period and studies will be done during spring-summer).
Get ahead of the latest EU requirements for plant protection products!
Contact us for assistance in the planning and conduct of trials according to the new OECD 254 guideline.
 |
|
Latest News
AgroAre you looking for information on agricultural testing for farmers and growers?
|