EAG and behavioral responses of Cacia cretifera thibetana to seven walnut tree volatiles
Author of the article:MAO Xiang-Zhong;YANG Bi;MA Yun-Qiang;ZHAO Ning
Author's Workplace: Yunnan Provincial Key Laboratory of Forest Biotechnology, Southwest Forestry University ; Key Laboratory of Forest Disaster Warning and Control in Yunnan Province , Southwest Forestry University
Key Words:Cacia cretifera thibetana; Juglans sigillata var ‘Santai’; volatile compounds; electroantennogram response; Y-type olfactory response
Abstract:
[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.