Test No. 255: Bumblebee (Bombus spp.), Chronic Oral Toxicity Test (10‑Day Feeding)

This Test Guideline describes a chronic oral toxicity test on adult worker bumblebees under laboratory conditions over an exposure period of 10 days. Adult worker bumblebees are individually exposed to 50 % (w/v) aqueous sucrose solution containing the test chemical through continuous and ad libitum feeding over a period of 10 days. Mortality and behavioural abnormalities are observed and recorded daily during the test period. The chronic effects of the test chemical are evaluated by comparing the results of the treated groups to those of the respective control group. The test is designed for the determination of the following endpoints: LC50 (Median Lethal Concentration) and the LDD50 (Median Lethal Dietary Dose) values, and NOEC (No Observed Effect Concentration) and NOEDD (No Observed Effect Dietary Dose).