Research Projects

Climate change poses a severe threat to biodiversity, potentially driving numerous species to extinction. The 2021 IPCC report confirms rising global temperatures and increased frequency of extreme weather events. Such hot extremes are expected to intensify, particularly in tropical regions, where temperatures could increase by 3–4℃, likely altering species’ distributions and phenologies. While studies show that heat stress can modify behaviour in non-human animals, few have examined the effects of extreme heat on cognition. Cognitive functions—such as perception, learning, memory, and decision-making—are essential for behavioural flexibility and help animals adapt to environmental stressors. Thus, understanding the cognitive impacts of heat stress is crucial. While it is well documented in humans and some animals, only a few studies have examined the effects of extreme heat on insect cognition, particularly in fruit flies. These findings indicate that cognition is negatively affected by heat stress. About 80% of flowering plants and 35% of crops depend on animal pollination, primarily by insects. However, it is unknown whether heat stress impairs cognition in insect pollinators, impacting their pollination efficiency. This research aims to address this gap by studying flower-visiting butterflies as model organisms. Butterflies have several life stages that are temperature – sensitive (egg, larval and pupal) and thus vulnerable to heat stress. Even though, some butterflies are considered as pests in their larval stages due to herbivoury they are important pollinators of crop and wild plants globally. The hypothesis is that exposure to hot extremes—as projected by the IPCC—induces cognitive impairments in butterflies, particularly during development. Eggs and larvae from wild butterfly populations will be used to establish a laboratory stock population. In experiments, butterflies will experience heat stress during different developmental stages—egg, larval, pupal, and adult—for both short and long durations. Cognitive effects will be assessed through different approaches: (a) Behavioural assays measuring innate preferences, associative learning, and sensory integration across behavioural contexts. (b) Since cognition is closely linked to sensory and neural physiology and anatomy, the research will also examine heat stress impacts on sensory organs (eyes and antennae) and brain morphology. Lastly, changes in biogenic amine levels, which affect motivation and learning, will be analysed. Findings from this study will shed light on how heat stress impacts the cognitive functions of insect pollinators, linking climate change with sensory physiology and cognitive performance. Understanding the impact of extreme heat on pollinators is crucial for developing effective conservation strategies to protect pollinator health and food security. The proposed research will provide essential information for this endeavor.