Meeting Abstract
Environmental stressors can influence phenotypic plasticity and life-history characteristics. The response to stress may be further altered by the presence beneficial symbionts. Pea aphids (Acyrthosiphon pisum) harbor facultative symbionts that can provide protection against natural enemies and pathogens. Furthermore, aphids under stress are able to produce winged progeny that may be better able to migrate to safer habitats. The interaction between symbiosis and phenotypic plasticity, and their interactive effect on aphid fitness, remains unclear. In this study, we investigate how stress via crowding drive shifts in fecundity and production of winged offspring, and how symbionts influence the process. In the winged morphotypes, energy needed for wing maintenance may lead to trade-offs with other traits, such as reproduction or symbiont maintenance. Thus, we explore the influence of symbionts on production and fitness of wing/wingless morphs across two generations. Crowding resulted in increased production of winged offspring and shifts in fecundity rates, however, presence of symbionts did not interact with crowding. Stress on first generation mother aphids did not have cross-generational impacts on second generation adults, where variation in fecundity was strictly based on the presence of secondary symbionts and presence/absence of wings. Our study suggests a complex interaction between beneficial symbionts and environmental stressors. Winged aphids have the advantage of being able to migrate out of danger with more ease, but energy needed for wing production and maintenance may come with reproductive costs for their mothers and for themselves, and, in certain cases, these costs are altered by symbionts.
