SUMMARY

1. Oxygen consumption, thoracic temperature, and action potentials from the fibrillar muscles were concurrently recorded in queens and workers of Bombus vosnesenstni. 2. The oxygen consumption of 'inactive ' bees (quiescent and/or pro-ducing fewer than 0-3 spikes/sec) was markedly temperature-sensitive, with a Qlo of 3-4 for thoracic temperatures of 25-35 °C-3. The oxygen consumption of bees with active fibrillar muscles was directly correlated with spike frequency; a single spike was associated with the consumption of 2-3-2-6 fil O2lgth- No oxygen debt was observed. 4. The oxygen consumption per spike during flight was similar to that during warm-up. 5. Oxygen consumption per gram thorax was similar in queens and workers engaging in similar activity. 6. The results are compared with those from other insects and their adap-tive significance is discussed