Assessing adult honey bee weight during a 10-day adult chronic laboratory bioassay

Project Objectives:

Background:

This project examines whether food consumption data from the 10-day adult chronic honey bee study (OECD 245) are suitable for assessing bee growth. The USEPA uses these measurements to calculate the mean test item dose as is instructed in the guideline. However, USEPA is also evaluating consumption as a proxy to assess potential effects on bee growth. This project aims to clarify the role of food consumption data as a study effect endpoint alongside survival. According to the OECD 245 guideline (2017), food consumption measurements are included solely to facilitate dose calculations and have not been validated for determining statistical differences in consumption, as the approach currently followed by the agency. While adult bees are generally not expected to grow due to their exoskeletons, variations in body weight may occur due to differences in food intake, as the mass of digestive contents can change. Therefore, this project focuses on understanding the relationship between food consumption and body weight, to accurately assess bee health in the context of the study design.