Life Table Parameters and Intrinsic Rate of Increase of Aphidius matricariae on Myzus persicae at Different Temperatures

Abstract

Aphidius matricariae Haliday (Hymenoptera: Braconidae) is a solitary endoparasitoid of considerable biocontrol relevance, widely deployed against the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), a polyphagous and economically destructive pest of numerous vegetable, ornamental, and field crops worldwide. Temperature exerts a fundamental regulatory influence on the developmental biology, reproductive output, and population growth dynamics of parasitoid–host systems, yet a quantitative characterization of thermal responses governing A. matricariae fitness parameters across a biologically relevant temperature range remains essential for optimizing mass-rearing protocols and predicting field efficacy under varying climatic conditions. This study determined the age-specific life table parameters and intrinsic rate of natural increase of A. matricariae reared on M. persicae at five constant temperatures of 10, 15, 20, 25, and 30°C under controlled laboratory conditions with standardized photoperiod and relative humidity. Developmental duration across all immature stages, adult longevity, age-specific fecundity schedules, parasitism rates, and mummy formation success were recorded and analyzed to construct temperature-specific life tables. Demographic parameters including the net reproductive rate, mean generation time, finite rate of increase, and doubling time were calculated using the age-stage, two-sex life table framework. Results indicated that developmental rate increased significantly with rising temperature, while reproductive performance and overall parasitoid fitness were maximized within an intermediate thermal optimum. Thermal biology parameters including the lower developmental threshold and thermal constant were estimated through linear regression modeling. These findings provide a quantitative foundation for improving biological control programs and predicting seasonal population dynamics of A. matricariae in aphid-integrated pest management systems.