Distribution, parasitoids and cyclic appearance of Russian wheat aphid Diuraphis noxia (Mordvilko, 1913) (Hemiptera, Aphididae) in Algeria

This information on the Russian wheat aphid Diuraphis noxia (Hemiptera, Sternorrhyncha, Aphididae) in those regions of Algeria where cereals are grown is based on a nineteen year study. This revealed that this aphid is widely distributed in the high plateaus and interior plains with semi-arid climates. The mummies of this aphid found among its colonies were collected and 4 parasitoids (Hymenoptera, Braconidae, Aphidiinae) where identified. These were Diaeretiella rapae (M’Intosh), Aphidius matricariae (Haliday), Aphidius rhopalosiphi (Destefani) and Lysiphlebus testaceipes (Cresson), with D. rapae the most abundant. Moreover, this study also indicates that the cyclical appearance of this aphid is determined by the intensity of precipitation during winter and spring.