Co-evolution of nuptial gift and female multiple mating resulting in diverse breeding systems

Abstract

To show how diverse breeding systems, including polyandry, evolve in insects, I present a model of co-evolution between nuptial gift size and female multiple mating. I assume that males and females determine their strategy (amount of nuptial gift and frequency of mating, respectively) according to the strategy adopted by the other sex. The model demonstrates that co-evolution leads to diverse breeding systems: systems with both nuptial gift and female multiple mating, systems with nuptial gift only and systems with neither nuptial gift nor female multiple mating. The equilibrium breeding system is determined based on the sex ratio, efficiency of nuptial gift on the improvement of offspring survivorship, cost of nuptial gift production and cost of additional mating.