Eco-Physiological Adaptation of Eurygaster integriceps (Hemiptera: Scutelleridae) to Seasonal Temperature Fluctuations in Wheat Fields

Abstract

Eurygaster integriceps is a key pest of wheat in many temperate cereal-growing regions, with its population dynamics strongly influenced by seasonal temperature fluctuations. The present study investigated the eco-physiological adaptations of E. integriceps to varying temperature regimes in wheat fields, focusing on survival, development, and reproductive performance across seasons. Field and controlled-environment observations were used to assess life history traits including developmental duration, adult emergence, fecundity, diapause behavior, and survival rates under fluctuating thermal conditions. The results indicated that E. integriceps exhibits strong adaptive mechanisms to seasonal temperature variation, enabling successful overwintering and synchronization with wheat phenology. Low winter temperatures induced diapause and reduced metabolic activity, allowing long-term survival, while gradual warming in spring triggered resumption of development and population buildup. Elevated temperatures during the growing season accelerated developmental rates and increased reproductive output up to an optimal threshold, beyond which survival and fecundity declined. The pest demonstrated behavioral and physiological plasticity, including microhabitat selection and thermal avoidance strategies, which enhanced its persistence in wheat ecosystems. Temperature-dependent population fluctuations highlighted the critical role of thermal conditions in regulating outbreak dynamics. The study underscores the importance of eco-physiological adaptation in shaping the pest status of E. integriceps in wheat agroecosystems. These findings provide valuable insights for predicting population outbreaks and improving timing of integrated pest management interventions under changing climatic conditions.