<p>Honeybee foragers load nectar into their crop upon leaving the hive and use it as fuel for flight. While the volume of this fuel nectar is known to be adjusted in response to various foraging conditions, adjustments in sugar concentration have been reported only in limited contexts. The present study examined the generality of concentration adjustment by comparing fuel loads between waggle dancers and dance followers, which are expected to experience different energetic demands. Regardless of foraging role, the concentration of fuel nectar increased with increasing foraging distance, as estimated from waggle-run durations. After controlling for the effect of foraging distance, dance followers were found to carry nectar with a significantly higher sugar concentration than waggle dancers. The volume of crop contents varied in parallel with nectar concentration. These results demonstrate that concentration adjustment is not restricted to specific situations and support the hypothesis that honeybee foragers regulate fuel loads through coordinated adjustments of both nectar volume and concentration according to anticipated energy demand.</p>