Strategies in energy consumption and partitioning in Collembola

Abstract. 1. Consumption (in Joules), partitioning of assimilated energy between maintenance (standard metabolism and locomotory activity) and prcduction (growth and reproduction) and assimilation efficiency were studied in the laboratory using adults of the coexisting species Orchesella cincta (L.) and Tomocents minor Lubbock (Collembola, Entomobryidae).
2. A higher energy demand for maintenance was established in O.cincta , compared with T.minor , caused by a higher mobility and a higher live weight-specific oxygen consumption (metabolic rate).
3. The energy required for higher maintenance in O.cincta , compared with T.minor , was derived from production, both from growth and reproduction.
4. The increase in live weight (in mg) during a moulting interval (feeding instar plus reproductive instar) was less in O.cincta than in T.minor , and was less in males than in females.
5. Reproduction (in Joules) was less in O.cincta than in T.ninor . The numbers of eggs produced were equal, but their energetic content was less in O.cincta . Survival of the eggs was similar.
6. Consumption (in Joules) and assimilation efficiency (on an energetic basis) during a moulting interval (feeding instar plus reproductive instar) were similar in both species.