Population metabolism of Nebria brevicollis (F.) (Coleoptera: Carabidae)

The respiratory metabolism of all life stages of a predatory beetle was investigated. Measurements were made throughout the year in a continuously recording respirometer. The Warburg respirometer was used to examine the relationship between oxygen cosumption and temperature.Respiration was affected by several factors. No periodicity in respiration was observed during the 24 hour period. During the breeding season the males showed a significantly higher respiratory rate than the females. Temperature influence was slightly greater on Instar I and adults in a breeding condition. Laboratory data were adjusted to field rates by using field temperature data and the regressions obtained from respiratory measurements made at different temperatures. Population estimates per m² were low. The seasonal trend in population metabolism was related to temperature. Population density and population production did not follow temperature closely.Population metabolism totalled 1735.95 Joules/m², of which 55.0% was due to adults. The production/respiration ratio (P/R) was 1:1. Total annual energy flux through the beetle population was 3365.13 Joules/m². The larvae accounted for 65% of this total.