BET HEDGING AND THE DIAPAUSE STRATEGIES OF THE CRICKET ALLONEMOBIUS-FASCIATUS

We investigated the roles of bet hedging and developmental plasticity in the diapause strategy of a partially bivoltine population of the cricket Allonemobius fasciatus. When reared under naturally changing environmental conditions, first-generation females produced increasing proportions of diapause eggs over their reproductive life-span, presumably reflecting the decreasing probability over time that sufficient growing season remains for a second generation. The transition from direct-developing to diapause eggs occurred over 35 d for the population, suggesting a considerable degree of bet hedging. The analysis of individuals, however, revealed a much more rapid response and large between-female variability in the median (50%) diapause date. This rapid transition from nondiapause to diapause eggs implies that interannual variability in season length has not resulted in the evolution of a substantial risk-spreading strategy for individual females. Our results highlight the need to study life history variation at the level of the individual rather than the population.