Generalist insect herbivore performance in dependence of plant species richness, composition and quality
The aim of the present thesis was to further disentangle the effect of plant species richness, composition and food plant quality on generalist insect herbivore performance in a combination of laboratory and field studies. Moreover, the effects of parental and early feeding experiences were analyzed. Finally, theoretical considerations about indirect effects of abiotic conditions on insect herbivore performance and the importance to combine knowledge of field and nutritional ecology integrate the current and other work into a review. The meadow grasshopper Chorthippus parallelus served as study organism for this thesis because its diet includes both, grasses and legumes. Furthermore, it is one of the most abundant grasshopper species in diverse meadow habitats throughout Europe. The studies have been conducted on or with food plants of meadows along a plant species diversity gradient within the biodiversity experiment BIOLOG (BIOLogical diversity and Global change funded by the BMBF 2000 -2010), located at the border between Thuringia and Bavaria in the mid of Germany.