This Test Guideline describes a chronic oral toxicity test on adult worker honey bees under laboratory conditions over an exposure period of 10 days. Young bees (max. 2 days old) are exposed to 50 % (w/v) aqueous sucrose solution containing the test chemical by continuous and ad libitum feeding over a period of 10 days. Mortality and behavioural abnormalities are observed and recorded daily during the 10 day test period. The chronic effects of the test chemical are evaluated by comparing the results of the test chemical treated group 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 after 10 days of exposure, and NOEC (No Observed Effect Concentration) and NOEDD (No Observed Effect Dietary Dose).