Abstract: The electrophysiological and olfactory responses of the four polyphagous predatory insect species, i.e., Coccinella septempunctata,Propylaea japonica, Chrysoperla sinica and Chrysopa septempunctata, to semiochemicals of wheat fed by wheat aphids were studied. Electrophysiological responses of all four species to 6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol, 2-camphene and methyl salicylate were stronger than that of the control. Response of Coccinella septempunctata to 6-methyl-5-hepten-2-ol was the strongest (0.96±0.18 mV). But these natural enemies had no response to E-2-hexenal. "Y"tube olfactory test showed that 6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol, 2-camphene and methyl salicylate were attractive to them. It was concluded that chemical cues induced by wheat aphid feeding play an important role in host and host habitat location of the four polyphagous predatory natural enemies.

Key words: Coccinella septempunctata, Propylaea japonica, Chrysoperla sinica;Chrysopa septempunctata, behavioral responses, EAG