Abstract: The functional responses of four species of natural enemies to the Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), were examined in laboratory in Xinjiang Uygur Autonomous Region. The responses of Aphelinus sp. And Coccinella septempunctata to RWA was showed to be the Holling I type and could be fitted by Na=0.6060N-3.4700 (n≤100) and N_a=0.6020N+5.9000 (n≤250) respectively, where N_a is number of the aphids attacked and N, the initial number of the aphids. The predation of Hippodamia variegata and Leucopis annulipes on the aphid could be well described by Holling II type, with the models as 1/N_a=1.2550/N+0.0046 and 1/N_a=1.3280/N+0.0071 respectively.

Key words: Russian wheat aphid (Diuraphis noxia (Mordvilko)), natural enemies, functional response