Increased size due to larval royal jelly exposure does not affect circadian locomotor activity or climbing ability in adult female Drosophila melanogaster

The effects of royal jelly (RJ) appear to be conserved in Drosophila; flies exposed of RJ exhibit increased body size, similar to queen bees. However, in flies and bees, there is evidence that increased body size can lead to impairments to locomotor activity, while RJ may have anti-fatigue properties. Canton-S and Oregon-R Drosophila larvae were raised on media containing 0% or 20% pure RJ. Climbing assays were conducted to assess vertical locomotion. Circadian locomotion was observed using Drosophila Activity Monitors. CS, but not Or-R, raised on RJ were larger compared to controls. Flies exposed to RJ exhibited entrainment and free-running rhythms. The increased size due to RJ exposure in this study had no bearing on circadian locomotor activity or climbing. These results indicate that there is variation among physiological responses to RJ among different strains, but RJ was equally ineffective in affecting locomotor behavior no matter the physiological response.