枣飞象对枣树植物挥发物的EAG和行为反应

【目的】枣飞象Scythropus yasumatsui是枣树Zizyphus jujuba主要害虫。近年来，在陕西和山西枣区暴发成灾，造成了严重的经济和生态损失。本研究旨在明确枣树挥发性物质在枣飞象成虫化学通讯中的作用，为该虫植物源引诱剂开发和研制提供基础资料。【方法】利用顶空吸附法收集5个枣树品种(木枣、狗头枣、赞皇枣、骏枣和酸枣)的枣芽挥发物，采用气质联用(GC-MS)进行化学指纹谱的鉴定和分析；随后分别利用触角电位(electroantennogram, EAG)仪和Y型嗅觉仪测定枣飞象成虫对17种枣树挥发性物质的EAG和行为反应。【结果】5个品种枣树的枣芽中共鉴定出挥发性物质6类26种，包括9种萜烯类、6种酯类、4种醇类、4种烷类、2种醛类和1种酚类；不同品种枣芽挥发性物质种类和含量具有差异。EAG试验结果表明，枣飞象成虫对测试的17种枣树挥发性物质的EAG反应相对值有明显差异。枣飞象成虫对D-柠檬烯、正十三烷、正十四烷、正十五烷、壬醛、棕榈酸甲酯、油酸甲酯7种挥发性物质的EAG反应较强。当挥发性物质浓度为0.1~100 μg/μL时，随着浓度增加，枣飞象成虫的EAG反应相对值先增加后下降，刺激浓度为50 μg/μL时EAG反应相对值达到最大。50 μg/μL浓度下，枣飞象雌成虫对棕榈酸甲酯和壬醛EAG反应相对值分别为3.84和3.67，雄成虫对棕榈酸甲酯和壬醛EAG反应相对值分别为3.47和3.21，极显著高于对其他挥发性物质的EAG反应相对值。行为反应结果表明，枣飞象雌雄成虫对棕榈酸甲酯和壬醛有明显趋向性, 选择率均大于65%，雄成虫对十五烷有明显趋向性，雌雄成虫对其他供试的物质无明显趋向性。【结论】棕榈酸甲酯和壬醛对枣飞象雌雄成虫均有明显吸引作用，十五烷对雄成虫有明显吸引作用。结果提示棕榈酸甲酯和壬醛可能与枣飞象对不同品种枣树偏好性选择密切相关。

EAG and behavioral responses ofScythropus yasumatsui(Coleoptera: Curculionidae) to volatiles from the common jujube (Zizyphus jujuba)

【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.