Attraction of adult Harmonia axyridis to volatiles of the insectary plant Cnidium monnieri

In this study, we tested the attractiveness of volatiles emanating from healthy and aphid-infested insectary plant Cnidium monnieri (L.) Cuss. to H. axyridis adults in a Y-tube olfactometer. Next, using coupled gas chromatography - electroantennogram detection (GC-EAD) and gas chromatography - mass spectrometry (GC-MS) identified the volatile components which elicited electrophysiological activity in H. axyridis adults. Lastly, Y-tube olfactometer tests in laboratory and field traps were used to verify the effectiveness of the volatile components. In olfactometer trials, H. axyridis adults preferred healthy and aphid-infested plants versus control. In GC-MS and GC-EAD trials, two antenna-active components (1,2-diethylbenzene and p-diethylbenzene) were detected among the volatile blends emanating from healthy and aphid-infested plants; and in ensuing behavioral assays, H. axyridis adults were attracted to two synthetic volatile compounds. Under field conditions, the number of H. axyridis adults as recorded in traps for two synthetic volatile components at three different concentrations (100mg/ml, 10mg/ml, and 1mg/ml) were significantly higher than those for mineral oil (control). These findings could provide an effective means for the cultivation of insectary plants to develop natural enemy attractants and support the biological control in the field.
Source: Biological Control - Category: Biology Source Type: research