Genetic and environmental sources of variation in survival on nonnative host species in the generalist seed beetle, Stator limbatus

Humans have introduced organisms into many new and often novel environments. These changes in organism distributions provide LIS an opportunity to directly observe the ecological and evolutionary processes that influence adaptation. Here we examine the suitability of a variety of introduced legume species, plus several non-host native species, for the development of Stator limbatus larvae. About half of the species examined were capable of supporting larval development, though larval survival was high on few non-host species. Maternal experiences during egg maturation affected larval survival on seeds of Parkinsonia aculeata and Ebenopsis ebano, but not on any other non-hosts; females that matured eggs in contact with seeds of Parkinsonia florida, a native host of S. limbatus in the Sonoran Desert, produced larger eggs and had offspring with higher survival on seeds of these 2 exotic species than if females did not encounter P. florida during egg maturation. Using a half-sib breeding design, we detected genetic variation in larval survival on seeds of P. aculeata, but found that maternal experience during egg maturation (whether or not females encountered seeds of P. florida) was the major factor affecting offspring survival on P. aculeata. We conclude that the ability of S. limbatus larvae to survive on some non-native plant species depends on the species composition of the local plant community female experiences with P. florida induce changes in egg size and composition that subsequently influence survival of larvae on seeds of the novel host, P. aculeata.