Trait-mediated indirect interactions: moose browsing increases sawfly fecundity through plant induced responses

1. Induced responses in plants, initiated by herbivory, create potential for trait-mediated indirect interactions among herbivores. Responses to an initial herbivore may change a number of plant traits that subsequently alter ecological processes with additional herbivores. Although common, indirect interactions between taxonomically distant herbivores, such as mammals and insects, are less studied than between taxonomically related species (i.e. insect-insect). In terms of mammal-insect interactions, effects on insect numbers (e.g. density) is relatively well studied, whereas effects on performance (e.g. fecundity) are rarely explored. Moreover, few studies have explored mammal-insect interactions on coniferous plants. 2. The aim of this study was to investigate the effect of mammalian induced responses on insect performance. We specifically investigated the effect of moose (Alces alces) browsing on Scots pine (Pinus sylvestris) and subsequent effects on sawfly (Neodiprion sertifer) p...