The role of learning and information use in response to temperature change in the seed beetle Callosobruchus maculatus

Climate change imposes increasing thermal stress on ectothermic organisms, affecting both physiological functions and behaviour. Cognitive plasticity, such as learning and information use can enable organisms to behaviorally buffer against unpredictable environments and temperature change, yet the temperature dependance of these cognitive traits remains poorly understood. In this thesis, I investigated the temperature dependence of learning and information use in the seed beetle Callosobruchus maculatus, measured through host search and oviposition behaviour, and compared it to the temperature dependence of the life history traits fertility and fecundity. Using controlled laboratory experiments, I simultaneously quantified cognitive and life-history traits across a broad temperature gradient (15°C– 47°C) under treatments that either provided environmental cues, generating expectations of future host quality, or not. Cognitive traits were significantly influenced by temperature, prior experience, and time (performance improvement between runs). Females with access to prior information consistently outperformed naïve controls in host search and choice, particularly at intermediate to high temperatures (~37°C). Performance declined at thermal extremes, indicating that learning and information use and fecundity are thermally constrained. In contrast, fertility showed to be more resilient to temperature change, suggesting canalized physiological control. These results demonstrate that cognitive traits are more plastic and environmentally sensitive than the life history traits measured in this study, highlighting how they could potentially compromise short-term adaptation to thermal stress. This study underscores the importance of incorporating cognition into models of climate change responses, particularly in species of ecological and agricultural relevance. anthropogenic relevance. Moreover, the differential thermal sensitivity of behavioural and physiological life-history traits suggests that behavioural plasticity may affect the strength of selection on correlated life-history traits as temperature changes.