Will legume-insect specificity break down as the climate changes?

Granivores are among the most troublesome consumers of commercial crops, but they are also some of the best and most effective candidates for biological control agents of exotic and invasive plants. It is important to understand how they might behave in future climate conditions so that we can predict how they host range with change, how they might break out of their current specific niches, how their geographical extent might reach into new areas, and how their populations could be controlled by their natural enemies such as parasitoid wasps. This thesis is a valuable community-wide survey of plant-insect interactions, centered on the insect cohort of south-east Australian legumes, a family of plants that is commercially and ecologically important. By using a distance-for-time design across the elevation gradient of the Blue Mountains, this work has laid out the insects that can be found in the legumes of this region, their niches in the community, the different configurations the communities take under different climate conditions, and the different seasonal host use responses of weevils, wasps, and moths under those conditions. This thesis is an informative foothold for future researchers who want to use legumes to study community-level plant-insect associations, the processes that form them, and what makes them break down. The information shared herein provides new model inputs to improve future models of insect expansion and host choice, and suggestions of further work that might build on its findings and strengthen them. I hope that this work contributes to a generalised understanding of insects’ response to climate change