Meeting Abstract
38.1 Wednesday, Jan. 5 Mating decisions vary according to environmental context, but in different ways for males and females GILLESPIE, Stephanie; TUDOR, Scarlett; MOORE, Allen; MILLER, Christine*; Univ. Florida; Univ. Florida; Univ. Exeter; Univ. Florida cwmiller@ufl.edu
Sexual selection has resulted in the evolution of some of the most striking and elaborate traits in the natural world. It occurs in naturally variable environments, however, the effect of environmental heterogeneity on the processes of sexual selection is still relatively unknown. Here, we first examined the influence of rearing environment on eventual male body size and sexually-selected trait expression. Next, we examined the influence of both rearing and adult environment on male and female mating decisions. This experiment was conducted with cactus bugs, Narnia femorata (Hemiptera: Coreidae). Juvenile cactus bugs naturally experience discrete differences in their diet, developing on cactus with or without cactus fruit. We reared juveniles on these two natural diets and found that those reared with cactus fruit were larger with larger sexually-selected traits. We next paired unmated adults on cactus with or without fruit and recorded mate discrimination. Overall, females were more likely to mate with larger males. However, females paired in a context with cactus fruit were less discriminating than females without cactus fruit. Males, interestingly, showed a similar, but opposite, pattern. Males paired in a context with cactus fruit were more discriminating for larger females than males without cactus fruit. These results reflect the natural history of cactus bugs. Females may be less discriminating on cactus with fruit because of other benefits of the plant, notably the quality of this resource for feeding and oviposition. Males are likely to be more discriminating on a cactus with fruit, because this high quality resource in nature would likely attract many females. This research demonstrates that not only the target of selection, but also the strength of selection itself, can be affected by natural variation in the environment.
