ABSTRACT
The effect of differential resource availability at different life-stages on population dynamics remains relatively unexplored for stage-structured populations. Here, we present analyses of census data from a 49-generation experiment on replicate laboratory populations of the common fruit fly, Drosophila melanogaster, subjected to four different combinations of larval and adult nutritional levels. We also investigate the mechanistic underpinning of the dynamics through a stage-structured individual-based model that incorporates life-history parameters common to many holometabolous insect populations. The model captures both the qualitative and the quantitative nature of the dynamics of each of the four nutritional regimes studied experimentally. Simulations using the model also resolve an observed discrepancy in terms of population size and stability between data from an earlier empirical study and our results, thus demonstrating the importance of quantitative description of the nutritional levels in understanding population dynamics and stability. Exploration of the model parameter space produces clear predictions regarding constancy stability of populations, as a consequences of altering life-history related traits in contrasting nutritional regimes. Data from an earlier independent experiment are used to validate one of the model predictions. Insights obtained from this study are useful in understanding the interaction of ecology and life-history in shaping the evolutionary dynamics of populations with life-cycles similar to Drosophila.