Convergence to the Stable Age Distribution in Populations of Insects

Abstract

This paper summarizes life history data for 27 species of insects demonstrating that in seasonal environments most populations of insects never experience a stable age distribution. Analysis of a simple model for population growth in nonlimiting environments shows what factors are most important in influencing the time to convergence on a stable age distribution. In this model the time to convergence is not sensitive to changes in juvenile or adult mortality rates, or to the area under the age-specific birth-rate curve. Changes in the age of first reproduction and the shape of the age-specific birth-rate curve most influence the time to convergence.