Effects of temperature and photoperiod on diapause of Aphidius gifuensis Ashmead

In order to investigate the optimal condition for mass rearing and storage of Aphidius gifuensis Ashmead, the variation of diapause rate of a dominant endoparasitoid of Myzus persicae (Sulzer) in tobacco-planting areas were studied under different temperatures and photoperiods. The results showed that under short-day condition (Light:Dark=8:16) at the temperature of 0℃, 5℃ and 10℃, the diapause rate of A. gifuensis was 71.12%, 55.50% and 45.71%, respectively; while under long-day condition (Light:Dark=14:10) at the same temperature, the diapause rate decreased to 44.53%, 24.18% and 0, respectively. However, the diapause of endoparasitoids was not induced at 25℃ and 30℃ either under long-day or short-day condition. It indicated that the interaction between low temperature and short-day increased the diapause rate of A. gifuensis, while long-day and high temperature inhibited its diapause.