01971nas a2200157   4500008004100000020001400041245012900055210006900184260000900253300001400262490000700276520135100283100002501634700001901659856013501678       2009                        eng d  a0014-382000aAdaptive dynamics of dormancy duration variability: evolutionary trade-off and priority effect lead to suboptimal adaptation0 aAdaptive dynamics of dormancy duration variability evolutionary   cJuly  a1879-18920 v633 aMany plants, insects, and crustaceans show within-population variability in dormancy length. The question of whether such variability corresponds to a genetic polymorphism of pure strategies or a mixed bet-hedging strategy, and how the level of phenotypic variability can evolve remain unknown for most species. Using an eco-genetic model rooted in a 25-year ecological field study of a Chestnut weevil, Curculio elephas, we show that its diapause-duration variability is more likely to have evolved by the spread of a bet-hedging strategy than by the establishment of a genetic polymorphism. Investigating further the adaptive dynamics of diapause-duration variability, we find two unanticipated patterns of general interest. First, there is a trade-off between the ability of bet-hedging strategies to persist on an ecological time scale and their ability to invade. The optimal strategy (in terms of persistence) cannot invade, whereas suboptimal bet-hedgers are good invaders. Second, we describe an original evolutionary dynamics where each bet-hedging strategy (defined by its rate of prolonged diapause) resists invasion by all others, so that the first type of bet-hedger to appear persists on an evolutionary time scale. Such "evolutionary priority effect" could drive the evolution of maladapted levels of diapause-duration variability.1 aGourbiere, Sebastien1 aMenu, Frederic  uhttps://weevil.myspecies.info/adaptive-dynamics-dormancy-duration-variability-evolutionary-trade-and-priority-effect-lead-suboptim02408nas a2200217   4500008004100000020001400041245012900055210006900184260001000253300001000263490000700273520162900280100002901909700002001938700002101958700002101979700001702000700001902017700001902036856013502055       2009                        eng d  a0307-696200aEcophysiological attributes of adult overwintering in insects: insights from a field study of the nut weevil, Curculio nucum0 aEcophysiological attributes of adult overwintering in insects in  cMarch  a61-700 v343 aDiapausing insect species have evolved a great diversity of life cycles, although overwintering occurs at a single development stage within most species. Understanding why diapause has evolved towards a given life stage requires investigation of both the ecological and physiological attributes. Notably, it is suggested that adult overwintering is more energy-demanding than larval overwintering but it brings fitness gains by allowing adults to be synchronized with their seasonal requisites through an early spring emergence. This hypothesis is tested in field conditions in the nut weevil Curculio nucum, whose life cycle comprises an obligate 2-year, nonfeeding underground phase, including a larval, followed by an adult, overwintering. In this species, adult wintering leads to an early spring emergence; at first glance, however, this does not enhance synchronization between weevils and their host because adults emerge more than 1 month before starting to breed. It is suggested that adult overwintering ultimately evolved in response to the phenology of the host, by allowing females to oviposit in nuts before their full sclerotinization. Adult overwintering appears to be costly because adults postpone reproduction for 1 year, incur a significant weight loss and require feeding before egg laying. Surprisingly, lipids are unaffected during diapause, lipogenesis even being likely in the summer metamorphosis. These results suggest that the lipids involved in egg production may entirely come from the larval stages, whereas the other nutrients are acquired through adult feeding but this remains to be tested.1 aBel-Venner, Marie-Claude1 aMondy, Nathalie1 aArthaud, Florent1 aMarandet, Julien1 aGiron, David1 aVenner, Samuel1 aMenu, Frederic  uhttps://weevil.myspecies.info/ecophysiological-attributes-adult-overwintering-insects-insights-field-study-nut-weevil-curculio-nuc