Population Energies of the Millipede, Narceus Americanus (Beauvois)

Abstract

Energy flow was investigated in 2 populations of Narceus americanus. A factorial experiment was used to determine rates of energy intake, excretory energy and assimilated energy over a range of temperature, humidity and food moisture conditions. The results of this experiment were applied to field data on environmental parameters and population biomass to predict the weekly energy flow during the active season. This prediction was evaluated by an experiment conducted in the field. The values for the 2 populations in kcal/m 2 /yr were 10.92 and 15.03 for energy intake, 9.20 and 12.82 for excretory energy and 1.63 and 2.20 for assimilated energy. The energy flow shows close correlations with life cycle events. Peaks of energy occurred during the early summer breeding season and in preparation for hibernation, and a low point during the August molt. These millipedes appear to be restricted in the microhabitat distribution by temperature and moisture conditions which make possible a positive energy balance.