7.2.4. Replenishing carbohydrates provided to caged adult workers in the laboratory
Care must be taken when renewing carbohydrates because workers are at a higher risk of escaping or being damaged during this time. In theory, 1 ml of 50% (weight/volume) sucrose solution should be adequate for approximately 100 individuals during a 24-hour period because adult workers require 4 mg useable sugar per day to survive (Barker and Lehner, 1974). As worker consumption may vary according to treatment, at least 5 ml of 50% (weight/volume) sucrose solution for 100 workers should be provided daily to ensure that they do not run out of food.
Carbohydrates should be replenished frequently to ensure they are provided ad libitum (i.e. caged workers are never without carbohydrates), or at least every three days to prevent microbial growth or drying when sucrose pastes are provided.
If carbohydrates cannot be provided ad libitum to honey bees in isolation cages, individuals can be fed to satiation immediately upon caging, and 16 µl (four 4 µl droplets) of approximately 30% (weight/volume) sucrose solution every 24 hours ; this should maintain them for at least one week (Felsenberg et al., 2011).