Oscillations in population numbers: age-dependent cannibalism

Examined larval cannibalism of eggs in flour beetle Tribolium. The dynamics of this interaction are the same as those of competition where a later life stage preempts resources used by an earlier life stage. A mathematical model of the egg-larval interaction allows for the evaluation of the impact of the duration of the egg and larval intervals, fecundity, survival and cannibalism rates on the stability of the equilibrium number of larvae. The local stability boundary, which separates the region of parameter space leading only to unstable equilibria and oscillations from that region yielding the possibility of stable equilibria, is dramatically modified by the inclusion of age-dependence in the cannibalism by larvae. In contrast to a model ignoring this age-dependence, the model which includes age-dependence predicts that all flour beetle cultures should display oscillations in larval numbers. -from Authors