Conflict of interest between sexes over cooperation: a supergame on egg carrying and mating in a coreid bug

In the golden egg bug (Phyllomorpha laciniata Vill. Heteroptera: Coreidae) females lay eggs on the backs of conspecifics, often on courting males. Alt hough the bugs do not provide care to the eggs, this decreases the risk of egg predation. As an effect males carry many eggs which are not their own. The male and female interests are in conflict; females need to find an ovip osition site, and male fitness depends on the obtained number of matings. B y using a very rare modeling approach, a supergame where the individuals ac tions change payoffs over time, we show that combinations of reciprocating strategies where males obtain a mating in return for a carried egg can be s table. The value of the mating, to males, is more important than the relate dness to the eggs in gaining their cooperation in carrying eggs. Females ma y also take advantage of the males without reciprocating. This is especiall y likely if the probability of future meeting is high and the value of a ma ting is high for the male. We relate our results to our own data from empir ical studies and experiments on the species. In the light of the results we discuss the behavior of the bugs in relation to nuptial gifts. We also dis cuss the general applicability of the supergame approach.