An Evolutionarily Stable Strategy (ESS) model of postcopulatory guarding in insects

Abstract

A simple Evolutionarily Stable Strategy (ESS) model for promiscuous insect species is analyzed to obtain the optimal strategy for the duration of male guarding behavior after copulation with a female. Such guarding behavior prevents other males from copulating with that female. Predictions of the model are (i) that the ESS is either a non-guarding strategy, a perfect guarding strategy until oviposition, or a polymorphic equilibrium between the two types, and (ii) that the perfect guarding strategy has more advantages than the non-guarding strategy when (a) the ratio of males to females is large, (b) the searching efficiency is high, (c) the population density is high, and (d) the preoviposition period is short. Male guarding behavior in several species seems to agree with the predictions of the model.