Diel rhythmicity of alcohol‐induced intoxication in the honeybee workers

Abstract

AbstractAmong the honeybee workers, extranidal foragers are more rhythmic in their diel activity and more likely to encounter alcohol than intranidal nurses. Foragers are more active and potentially exposed to alcohol during the day, while nurses work around the clock and probably never encounter alcohol. Here, we took advantage of these differences and checked for a connection between the effects of alcohol and period of the day. We hypothesized that foragers would show higher intoxication resistance to alcohol than nurses during the day. Furthermore, we hypothesized that only in foragers the intoxication resistance to alcohol would be different between day and night. We detected higher intoxication resistance to alcohol in older, forager‐age bees, than in younger, nurse‐age bees during the day, which confirmed the first hypothesis. However, the intoxication resistance differed between day and night in both worker types, which provided no support for the second hypothesis. Surprisingly, we found the intoxication resistance to be highest during the night in both types of workers. Reported differences in the intoxication resistance showed no relation to differences in alcohol absorption between day and night, thus the exact mechanistic explanation for the diel oscillation in alcohol influence on bees remained unclear.