Effect of short-term high temperatures to the survival and parasitism of thekoinobiont endoparasitoid Venturia canescens (Hymenoptera: Ichneumonidae)against Plodia interpunctella (Lepidoptera: Pyralidae)

Abstract: Effect of short-term high temperatures on survival rates, longevity and parasitizationefficiency of Venturia canescens Gravenhorst (Hymenoptera: Ichneumonidae) parasitizing larvaeof Plodia interpunctella Hübner (Lepidoptera: Pyralidae) was studied in the laboratory.Experimental adults of V. canescens were exposed for 1 hour under various temperature regimes(37, 38, 38.5, 39, 39.5, 40, 40.5 and 41°C) in a circulating bath. The temperature that caused 50and 90% mortality was 39.26 and 40.64°C respectively. Longevity of V. canescens after beingexposed for 1 hour to high temperatures was significantly reduced compared to the control.Moreover, V. canescens lost gradually its parasitization efficiency as it was exposed to highertemperature regimes. After only 1 hour being exposed to 39 and 40°C, parasitization efficiencydropped by 63 and 69% respectively, in comparison to control.