多异瓢虫对瓜蚜为害后植物挥发物的行为反应及挥发物成分分析

为明确寄主植物挥发物在多异瓢虫Hippodamia variegata (Goeze)搜索猎物过程中的作用， 采用Y型嗅觉仪测定了多异瓢虫成虫对来自瓜蚜Aphis gossypii Glover、 健康植株、 有蚜植株及蚜害植株本身的挥发物的行为反应。结果表明： 高密度蚜虫（≥700头/L）、 有蚜植株以及密度≥400头/盆的蚜虫为害诱导的黄瓜挥发物和密度≥200头/盆的蚜虫为害诱导的搅瓜挥发物对多异瓢虫成虫具有明显的引诱作用， 而低密度蚜虫（≤500头/L）和健康植株挥发物没有引诱作用。应用动态顶空收集法提取健康植株、 有蚜植株及蚜害植株的挥发物， 进行气质联用仪分析鉴定。结果表明， 从黄瓜健康植株、 蚜害植株和有蚜植株中分别鉴定出8， 12和18种挥发物， 主要组分为十八烯、 E-5-二十碳烯、 正十六烷和正十七烷， 诱导出的新组分为对二甲苯、 邻二甲苯、 正十三烷、 α-法呢烯、 雪松醇、 正十八烷、 正二十六烷及7种未知种类； 从搅瓜健康植株、 蚜害植株和有蚜植株分别鉴定出11， 18和20种挥发物， 主要组分为石竹烯、 十八烯、 正十六烷和正十七烷， 诱导出的新组分为苯乙烷、 对二甲苯、 间二甲苯、 α-蒎烯、 正十四烷、 长叶烯、 α-石竹烯及2种未知种类。上述结果为进一步研究挥发物中引诱多异瓢虫的有效组分奠定了必要的基础。

Behavioral responses of Hippodamia variegata (Coleoptera:Coccinellidae) to volatiles from plants infested by Aphis gossypii (Hemiptera: Aphidae) and analysis of volatile components

In order to investigate the roles of volatiles from host plants in the process of Hippodamia variegata (Goeze) searching for preys, the behavioral responses of the lady beetle adults to volatiles from Aphis gossypii Glover, intact plants, aphid plant complex and aphid infested plants were observed with a Y-tube olfactometer. The results showed that the adults were significantly attracted to volatiles from high-density (≥700 individuals/L) aphids, aphid-plant complex, and aphid-infested Cucumis sativus plants (aphid density≥400 individuals/pot) and Cucurbita pepo var. medullosa plants (aphid density≥200 individuals/pot), while not to volatiles from low-density (≤500 individuals/L) aphids and the intact plants. Dynamic headspace collection was used to extract volatiles from the intact plants, aphid-plant complex and aphid-infested plants, respectively, and the extracted volatiles were analyzed by gas chromatography-mass spectrometry (GC-MS). Eight, twelve and eighteen components were identified from the extracts of the intact plants, aphid-infested plants and aphid-plant complex of C. sativus, respectively. The main components include 1-octadecene, ［E］-5-eicosene, hexadecane and heptadecane, and aphid-induced components are p-xylene, 1,2-dimethy-benzene, tridecane, 1-tetradecene, α-farnesene, cedrol, octadecane, hexacosane and other seven unknown components. Eleven, eighteen and twenty components were identified from the extracts of the intact plants, aphid-infested plants and aphid-plant complex of C. pepo var. medullosa, respectively. The main components include α-caryophyllene, 1-octadecene, hexadecane and heptadecane, and aphid-induced components are ethylbenzene, p-xylene, m-xylene, α-pinene, tetradecane, longifolene, α-caryophyllene and other two unknown components. The results lay a necessary foundation for further research on the effective components to attract lady beetles.