Deciphering the Impact of Thermal Stress on Metabolic Responses in Spodoptera litura (Fabricius)

In ectothermic species such as insects, temperature significantly influences development and survival. This study examines the effects of thermal stress on metabolic response of Spodoptera litura (Fabricius), a major agricultural pest, to understand how varying thermal conditions, intensified by climate change, affects its physiology. Eggs and larvae were subjected to 42°C and 46°C for 4 h and 1 h respectively in a single and multiple basis for 2 and 4 consecutive days for eggs and larvae respectively. The study measured water content, protein, carbohydrate, and glycogen levels in adults emerging from these heat stressed stages. Results indicated significant reductions in water content and increase in protein, carbohydrate, and glycogen levels under higher temperatures and repeated stress exposures. Females demonstrated higher resilience, evidenced by higher water and protein content compared to males. The findings suggest that S. litura's physiological adaptations to thermal stress involve complex metabolic adjustments, enhancing thermotolerance. This study provides insights into the potential impacts of climate change on S. litura populations and underscores the necessity for sustainable pest management strategies. Key findings include stage-specific differences in thermal sensitivity, with larvae showing greater susceptibility to heat stress, and the critical role of metabolic plasticity in insect resilience. Understanding these metabolic responses is crucial for predicting pest dynamics and developing effective control measures in a changing climate. This study contributes to the broader knowledge of ectothermic pest adaptation to environmental stressors, emphasizing the integration of physiological data into pest management framework.