Thermal Biology and Population Growth Parameters of Tetranychus ludeni (Acari: Tetranychidae) on Eggplant

Abstract

Thermal biology and population growth parameters of Tetranychus ludeni (Acari: Tetranychidae) were investigated on eggplant (Solanum melongena L.) to determine its developmental performance and reproductive potential under different temperature regimes. Laboratory experiments were conducted at a range of constant temperatures, and developmental duration, survival rate, fecundity, and life table parameters were recorded across immature and adult stages. Results indicated that developmental rate increased with temperature up to an optimum threshold, beyond which survival and reproduction declined due to thermal stress. The shortest developmental time and highest fecundity were observed at moderately warm conditions, indicating favorable thermal suitability for population buildup. Life table analysis revealed elevated intrinsic rate of increase, finite rate of increase, and net reproductive rate at optimal temperatures, demonstrating strong population growth potential under warm climatic conditions typical of tropical and subtropical regions. Conversely, extreme temperatures negatively affected egg hatchability, immature survival, and adult longevity, leading to reduced population expansion. Thermal constants estimated for development provided baseline data for predicting field phenology and seasonal outbreaks. The study also demonstrated a rapid population doubling time under optimal conditions, highlighting the pest’s capacity for explosive population growth on eggplant. Temperature-dependent regression models further confirmed the strong relationship between thermal conditions and developmental acceleration. These findings emphasize the significance of temperature as a key ecological factor regulating T. ludeni population dynamics and provide critical information for forecasting infestation risk. The results support the integration of temperature-based predictive models into pest management strategies for timely intervention and sustainable management of spider mite infestations in eggplant cultivation systems.