关键词: 枣飞象, 枣树, 挥发性物质, 触角电位, 行为反应, GC-MS

Abstract: 【Aim】 Scythropus yasumatsui is an important pest of the common jujube (Zizyphus jujuba) and has broken out in Shaanxi and Shanxi provinces in recent years, causing considerable economic and ecological loss. The purpose of this study is to demonstrate the role of jujube volatiles in chemical communication in S. yasumatsui adults, so as to provide basic data for the development of botanical attractants for weelives. 【Methods】 The volatiles from buds of five common jujube cultivars (Muzao, Goutouzao, Zanhuangzao, Junzao, and Suanzao) were collected by headspace absorption device and then identified and quantified with gas chromatography and mass spectrometry (GC-MS). The EAG and behavioral responses of S. yasumatsui adults to 17 volatile compounds of the common jujube were assayed with electroantennogram (EAG) apparatus and Y-tube olfactometer, respectively. 【Results】 A total of 26 volatile compounds of six groups, including 9 terpenes, 6 esters, 4 alcohols, 4 alkanes, 2 aldehydes and 1 phenol, were indentified from buds of five common jujube cultivars. The volatile compounds and their contents were different in buds of different common jujube cultivars. The EAG test results showed that there were significant differences in the relative EAG response value in S. yasumatsui adults to the tested 17 volatile compounds from the common jujube. The EAG responses of S. yasumatsui adults to D-limonene, n-tridecane, n-tetradecane, n-pentadecane, nonaldehyde, methyl hexadecanoate and methyl oleate were strong. With the increase of the concentration of volatile compounds ranging from 0.1 μg/μL to 100 μg/μL, the relative EAG response values in female and male adults increased first and then decreased. The highest EAG responses occurred at the volatile concentration of 50 μg/μL. The EAG values of female adults to 50 μg/μL of methyl hexadecanoate and nonaldehyde were 3.84 and 3.67, respectively, and those of male adults to these two compounds were 3.47 and 3.21, respectively. At the concentration of 50 μg/μL, methyl hexadecanoate and nonaldehyde elicited significantly higher EAG response of S. yasumatsui adults than other volatile compounds. Behavioral response tests showed that both female and male adults of S. yasumatsui showed obvious taxis to nonaldehyde and methyl hexadecanoate with the selection rate higher than 65%, male adults also showed significant taxis to n-pentadecane, and female and male adults showed no significant taxis to the other volatile compounds tested. 【Conclusion】 Nonaldehyde and methyl hexadecanoate are attractive to both female and male adults of S. yasumatsui, while n-pentadecane is attractive only to male adults. The results suggest that nonaldehyde and methyl hexadecanoate may account for the preference of S. yasumatsui to Z. jujuba.

Key words: Scythropus yasumatsui, Zizyphus jujuba; volatile compounds, electroantennogram, behavioral response, GC-MS