Impact of Constant and Fluctuating Temperatures on Development and Fertility of <scp><i>Myzus persicae</i></scp> Sulzer (Hemiptera: Aphididae)

ABSTRACT This study evaluates the effects of constant and fluctuating temperatures on the development, survival, and fertility of Myzus persicae , with an emphasis on understanding how thermal variability shapes its life history traits. Moderate temperature fluctuations (10 ± 5°C, 15 ± 5°C, 20 ± 5°C, and 25 ± 5°C) significantly enhanced developmental rates and reproductive success compared to constant conditions, demonstrating increased metabolic efficiency and adaptability under variable thermal environments. In contrast, extreme fluctuations (30 ± 5°C) imposed physiological stress, leading to delayed development, reduced survival, and decreased reproductive output, indicating limited tolerance of M. persicae to high thermal variability. A temperature‐dependent model revealed an optimal range around 25°C for developmental efficiency and reproductive performance. Fertility peaked at 20 ± 5°C but was markedly suppressed at 30 ± 5°C, underscoring the detrimental effects of extreme thermal fluctuations on population growth. These findings suggest that moderate thermal variability may promote population expansion of M. persicae under favorable conditions, whereas extreme fluctuations could act as natural constraints, limiting its dynamics in warmer climates. This study provides critical insights into the adaptability of M. persicae to thermal variability, offering a framework for predicting its responses to climate change. However, the observed physiological limitations under elevated temperatures highlight the need for further field‐based studies that incorporate ecological complexity. Such research will be essential to improve predictions of M. persicae population dynamics and to develop informed pest management strategies in agroecosystems experiencing increasing temperature fluctuations.