Resource acquisition & allocation in stressful environments: Stressful environmental conditions –including extreme climate and the shortage of food– are expected to heighten resource allocation tradeoffs between competing traits (e.g., growth vs. flight vs. fecundity). Our understanding of these tradeoffs has been largely based on Y-models of allocation, which depict how a fixed amount of resources, from a single pool, must be divided between two (or more) competing traits. In most systems, however, the acquisition and allocation of resources underlying tradeoffs are not fixed. We combine nutritional manipulations, respirometry, and stable-isotopes labeling experiments, to track the acquisition and fate of specific nutrients across a complete life cycle, as these modulate an important life-history tradeoff: that of flight vs. fecundity in the cabbage white butterfly, Pieris rapae. Studies in this project will help us to answering the fundamental question of whether and how organisms can overcome resource-based tradeoffs, while improving our understanding of how stressful environments impact plant-insect in
Effects of anthropogenic land use on plant-insect interactions: Localized climate change can shape insect behavior and physiology in fragmented landscapes. Such changes in microclimate may also have indirect but important effects on herbivore insect populations, by altering the nutritional quality of plants. On one side, the plant stress hypothesis proposes an increase in insect herbivory due to increased resource availability (incl. nitrogen) and reduced defenses in stressed plants. At the same time, some studies have suggested that stressed plants often alter the amount and composition of floral nectar (e.g., sugars and amino acids), and thus may modify plant-pollinator interactions in various ways. While these studies have contributed greatly to our understanding of the effects of climate change on plant-insect interactions, they usually provide only a plant perspective and rarely consider that effects on the herbivore and pollinator may not be independent from each other. One goal of my research program is to disentangling the different pathways through which nutritional shifts in stressed plants may impact the behavior and physiology of P. rapae, a butterfly that often feeds on the floral nectar of their host plants.