Article révisé par les pairs
Résumé : Respiration is quantitatively the most important element in the energy budget of the ground beetle Abax ater. It was measured in a Gilson respirometer for all developmental stages (except for the eggs), taking as many parameters as possible into account. The standard metabolic rate (SMR) increased exponentially with temperature in the range 5-15 °C but no metabolic acclimation to temperature was observed. A single relationship was found between body mass and respiration for all the active stages. Adult males regularly had a SMR slightly higher than did females, but the difference was seldom significant and may be explained by differences in body mass. At constant temperature SMR exhibited a daily cycle with two peaks occurring in the first half of the night and in the morning. It also exhibited an annual cycle with a maximum in the summer. SMR was up to twice higher than the basal metabolic rate (BMR), and the activity metabolic rate (AMR) of running individuals was two to three times higher than SMR. Respiration increased to twice SMR the day after a full meal owing to digestion, and then decreased for three days. The respiratory quotient (RQ) of 0.72 suggested that mainly lipid molecules were oxidised in A. ater respiration. Measurements of respiration by gravimetry gave results that were close to BMR. Besides the classical relationships of respiration with temperature and body mass, this work showed the significant influences of digestion and mobility on respiration: taking them into account realistically required multiplying SMR by a factor 2.3 during the active part of the annual cycle of A. ater. This correction allowed balanced energy budgets to be obtained.