Table 1.

Summary of experiments

ExperimentExperimental manipulationExperimental conditionsResults
1Nurse-age workers were caged on a broodless honey comb inside the hiveHive: +Behavior: caged bees showed activity rhythms similar to those of foragers, nurses were active around the clock.
Brood: −
Queen: +?Clock gene expression: strong oscillations in caged bees and foragers but not in nurses.
Comb: +
IL: LD
2Nurses were caged on a brood-containing or broodless comb outside the hiveHive: −Behavior: nurses with brood were active around the clock; nurses without brood were more active during the day.
Brood: +/−
Queen: −Clock gene expression: strong oscillations in nurses caged without brood and in foragers, attenuated oscillations in nurses caged on a comb with brood.
Comb: +
IL: LD
3Nurses were transferred to individual cages in constant lab environmentHive: −Nurses showed circadian rhythms in locomotor activity shortly after transfer to the lab.
Brood: −
Queen: −
Comb: −
IL: entrainment in LD, monitoring in DD
4A group of nurses were removed from the hive to a cage for 16 h and then sampled every 4 hHive: −Strong oscillations in foragers, weaker but significant oscillations in nurses that were transferred to a cage, attenuated oscillations in nurses.
Brood: −
Queen: −
Comb: +
IL: LD
5A group of nurses were removed from the hive to a cage for 8 h and then sampled every 4 hHive: −Strong oscillations in foragers, attenuated oscillations in nurses and in nurses that were transferred to a cage.
Brood: −
Queen: −
Comb: +
IL: LD
  • IL, Illumination regime; LD, 12 h light/dark; DD, constant dim red light.