[Objectives] To investigate the electroantennogram and olfactory behavioral responses of male and females of the beetle Cacia cretifera thibetana to seven volatile compounds derived from a host plant of this pest, the walnut Juglans sigillata var ‘Santai’. [Methods] Electroantennogram (EAG) and Y-tube olfactometer assays were employed to investigate the responses of C. cretifera thibetana to seven volatile components from J. sigillata var ‘Santai’. [Results] The EAG results show that the tested concentrations of all seven compounds elicited responses from both male and female beetles. The weakest EAG responses were to volatile concentrations of 0.000 4 mol/L and the highest to concentrations of 0.4 mol/L. The strongest EAG responses by males and females, 1.84 and 1.74, respectively, were elicited by nonanal. Y-tube behavioral assays showed that, within a certain range of concentration, six compounds, including alpha-pinene, beta-pinene, 1-caryophyllene, nonaldehyde, eucalyptus oil alcohol and trans-2-hexenal, were attractive to male and female beetles. N-hexyl aldehydes, however, had a repellent effect on both sexes. At a volatile concentration of 2 mol/L, females were most attracted by nonaldehyde whereas males preferred beta-pinene; chemotaxis rates of each sex for each compound were 95% and 87%, respectively. N-hexaldehyde had a repellent effect on both sexes, eliciting chemotaxis rates of 87% and 78%, respectively. [Conclusion] All seven compounds induced an EAG response, and six, including alpha-pinene, bet-pinene, 1-caryophyllene, nonaldehyde, eucalyptus oil alcohol and trans-2-hexenal, were attractive to both sexes. Only one compound, n-hexenal, had a repellent effect. These results provide a foundation for further research on attractants for C. cretifera thibetana.
