Chemical Compounds Emitted from Mentha spicata Repel Aromia bungii Females

Simple Summary Aromia bungii (Faldermann) (Coleoptera: Cerambycidae) is a serious wood borer of stone fruit trees. Native to parts of Asia and Russia, this beetle recently invaded Germany, Italy, and Japan, causing enormous economic losses. Repellents are effective and sustainable control methods of insect pests. In this study, we identified the A. bungii female-repellency ingredients from Mentha spicata: myrcene, (S)-(+)-carvone, (E)-beta-caryophyllene, and borneol, as well as their recommended quantities for use. These results contribute to research on repellents that prevent infestation and damage caused by A. bungii. Aromia bungii (Coleoptera: Cerambycidae) is an economically important wood-boring insect pest of stone fruit trees, particularly Prunus persica, in China. It has entered Japan and several European countries as an invasive species in recent years. It is difficult to control because of the cryptic feeding behaviour of larvae beneath the bark. Identification of repellent constituents from non-host plants has potential for use in management strategies against this beetle. Mentha spicata is cultivated extensively in Hebei Province (China) as a medicinal plant. Firstly, antennal responses of female A. bungii to M. spicata volatiles were evaluated by coupled gas chromatography-electroantennograms (GC-EAD), and then the EAD-active components were tested in semi-field trials. The results showed that A. bungii females were significantly repelled by myrcene, (S)-(+)-carvone, (E)-beta-caryophyllene, and borneol compared with the control. The presence of myrcene (100 mu L; 90% purity), (S)-(+)-carvone (200 mu L; 96% purity), (E)-beta-caryophyllene (500 mu L; 98.5% purity), and borneol (800 mu L; 80% purity) significantly reduced the perching rates of A. bungii females on both peach logs and leaves. Considering cost and commercial availability, we suggest that myrcene, (S)-(+)-carvone, and (E)-beta-caryophyllene could be promising repellents against A. bungii females in the field.