Evolution of periodicity in insect mate-seeking behaviour: A male-female coevolutionary game model

It is widely observed that mate-seeking behaviour in insects starts suddenly at a species-specific time and lasts at most for a few hours (i.e. periodic). Although several hypotheses have been proposed to explain why periodicity occurs, none has incorporated a game-theoretical situation within and between the sexes at the same time. Using a theoretical model, we show that the coevolution of mating strategies can result in the emergence of two distinct population level phases: with and without mate seeking. In the mate-seeking phase, all individuals (male or female) search for mates, whereas no individuals seek mates in the phase without mate seeking. If there are individuals that do not seek mates in the mate-seeking phase, the model predicts that these should be of the sex with (1) lower survivorship during mate-seeking behaviour; (2) higher survivorship during nonmate-seeking behaviour; (3) higher expected future reproductive potential or (4) the sex towards which the sex ratio is biased. Furthermore, the model predicts that the mate-seeking phase is favoured when individuals have (1) high searching efficiency, (2) high survivorship during mate-seeking behaviour of either males or females, (3) low survivorship during nonmate-seeking behaviour of either males or females, or (4) low future reproductive potential for either males or females. In addition, the model suggests the existence of a critical environmental condition that divides these two phases, predicting that gradual changes in this condition trigger a sudden transition between the mate-seeking and nonmate-seeking phases.