Electroantennogram and behavioral responses of Pissodes nitidus to terpene volatiles of Pinus koraiensis

In this study, we tested the electroantennographic (EAG) and behavioral responses of the weevil (Pissodes nitidus) to eight volatile compositions released from red pine (Pinus koraiensis). The volatiles include (1S)-(－)-α-pinene, (1R)-(＋)-α-pinene, (1S)-(－)-β-pinene, camphene, β-myrcene, careen, D-limonene and ocimene in a series of concentrations, i.e., 0.000 4, 0.004, 0.04, 0.4 and 0.8 mol/L. The results show that the weevil had higher EAG responses to all eight volatiles in five concentrations compared with the control (P0.05) and its EAG responses intensified with increased concentrations of volatiles. (1S)-(－)-α-pinene and (1R)-(＋)-α-pinene caused the most significant EAG responses with concentrations of 0.4 and 0.8 mol/L. The behavioral responses to the eight volatiles were also examined with a Y-tube olfactometer. The weevils presented significantly repellent behavior to D-limone with concentrations of 0.4 and 0.8 mol/L and the repellent rate was 62.5% to 80%. Except β-myrcene, the weevils were attracted to the other six volatiles and most significantly inclined to 0.4 mol/L of (1S)-(－)-α-pinene, (1R)-(＋)-α-pinene and ocimene, with trapping rates of above 80%. These volatiles assayed in this study, especially (1S)-(－)-α-pinene, (1R)-(＋)-α-pinene, ocimene and D-limone, may be potentially useful as repellents or attractants for the control and management of P. nitidus.