绿盲蝽雄虫体外挥发物研究

采用气质联用和嗅觉仪对分部解剖的绿盲蝽Apolygus lucorum(Meyer-Dür)雄虫体外挥发物进行鉴定和生测。结果表明:绿盲蝽雄虫浸提物中的主要组分有13种,包括醇类、酸类和酯类。相对含量较高的依次有丁酸己酯、反-2-丁酸己烯酯和己醇。绿盲蝽雄虫从交配不活跃期进入活跃期,其体内的丁酸己酯、反-2-丁酸己烯酯和己醇的含量都明显变化,其中丁酸己酯和反-2-丁酸己烯酯明显增加,而己醇的含量减少,表明绿盲蝽雄虫在交配活跃期,可能有大量的丁酸己酯和反-2-丁酸己烯酯释放到体外。比较绿盲蝽雄虫的不同部位的浸提物的含量,发现丁酸己酯、反-2-丁酸己烯酯和己醇主要存在于虫体胸部。嗅觉反应测试中绿盲蝽雌虫对丁酸己酯和反-2-丁酸己烯酯有明显的趋性,同时含量很少的丁酸庚酯对雌虫有明显引诱作用。因此推测丁酸己酯、反-2-丁酸己烯酯和丁酸庚酯可能是绿盲蝽雄虫释放到体外的挥发性引诱成分,并主要由胸部内的腺体分泌。     

Analysis of compounds extracted from male Apolygus lucorum

采用气质联用和嗅觉仪对分部解剖的绿盲蝽Apolygus lucorum (Meyer-Dür)雄虫体外挥发物进行鉴定和生测.结果表明:绿盲蝽雄虫浸提物中的主要组分有13种,包括醇类、酸类和酯类.相对含量较高的依次有丁酸已酯、反-2-丁酸已烯酯和已醇.绿盲蝽雄虫从交配不活跃期进入活跃期,其体内的丁酸已酯、反-2-丁酸已烯酯和已醇的含量都明显变化,其中丁酸已酯和反-2-丁酸已烯酯明显增加,而已醇的含量减少,表明绿盲蝽雄虫在交配活跃期,可能有大量的丁酸已酯和反-2-丁酸已烯酯释放到体外.比较绿盲蝽雄虫的不同部位的浸提物的含量,发现丁酸已酯、反-2-丁酸已烯酯和已醇主要存在于虫体胸部.嗅觉反应测试中绿盲蝽雌虫对丁酸已酯和反-2-丁酸已烯酯有明显的趋性,同时含量很少的丁酸庚酯对雌虫有明显引诱作用.因此推测丁酸已酯、反-2-丁酸已烯酯和丁酸庚酯可能是绿盲蝽雄虫释放到体外的挥发性引诱成分,并主要由胸部内的腺体分泌.     

绿盲蝽对性信息素类似物和植物挥发物的触角电位反应

为了更好地利用性信息素类似物与植物挥发物对绿盲蝽Lygus lucorum进行监测和生物防治, 本研究采用电生理学方法测试了绿盲蝽成虫对9种性信息素类似物和12种植物挥发性物质的触角电位(electroantennogram, EAG)反应。结果表明: 在测试的这21种化合物中, 绿盲蝽对丁酸酯类化合物和绿叶气味物质的EAG反应较强; 雄虫对性信息素类似物比雌虫更敏感, 而雌虫对植物挥发物更敏感。其中性信息素类似物中, 绿盲蝽对反-2-丁酸己烯酯的EAG反应最强; 植物挥发物中, 绿盲蝽对反-2-己烯醛的EAG反应最强, 雌虫对反-2-己烯醇、反-2-己烯醛、顺-3-己烯醇等绿叶气味物质的EAG反应相对高于萜类化合物的反应。剂量反应曲线表明, 在测定的浓度范围内, 雄虫对反-2-丁酸己烯酯的反应比雌虫显著高, 而对β 蒎烯的反应则比雌虫显著低。绿盲蝽成虫对性信息素类似物和植物挥发物的EAG反应存在的两性差异具有生态适应意义: 雄虫对性信息素类似物更敏感将更有利于其寻找交配对象, 而雌虫对绿叶气味物质更敏感将更有利于其寻找产卵寄主。     

绿盲蝽气味受体基因AlucOR40的克隆及功能研究

【目的】从绿盲蝽Apolygus lucorum触角中克隆气味受体基因Aluc OR40,研究该气味受体基因在绿盲蝽不同组织中的表达水平,然后对该基因的功能进行研究,为理解绿盲蝽的嗅觉识别机制提供理论基础。【方法】在绿盲蝽成虫触角转录组测序与分析的基础上,通过PCR技术克隆得到气味受体基因Aluc OR40的全长序列。用半定量RT-PCR研究该基因在雌雄虫不同组织中的表达水平。然后通过爪蟾卵母细胞体外表达该基因,并结合双电极电压钳检测了该气味受体对60种气味分子包括绿盲蝽性信息素组分和植物挥发物的反应。然后,利用触角电位技术测定羽化后3 d的绿盲蝽成虫对Aluc OR40的气味配体的触角电位反应。【结果】克隆了Aluc OR40(Gen Bank登录号:KU886190)。Aluc OR40编码398个氨基酸,蛋白具有7个跨膜结构域,N末端位于胞内,C端位于细胞外,符合昆虫气味受体的典型特征。半定量RT-PCR的结果显示,Aluc OR40在触角中特异表达,且在雄虫触角中的表达水平高于雌虫。双电极电压钳记录结果显示,Aluc OR40只对反-2-己烯醇一种气味分子具有特异反应。EAG实验结果表明,羽化后3 d的绿盲蝽雌雄虫都对反-2-己烯醇有反应,且雄虫触角的EAG反应显著高于雌虫。【结论】结果提示Aluc OR40参与了绿盲蝽对反-2-己烯醇的识别过程,推测其在绿盲蝽交配过程中雄虫对雌虫的识别中发挥作用。     

盲蝽科昆虫性信息素研究概况

盲蝽科MIridae昆虫具有重要的经济价值,包含许多农林业的重要害虫和一些害虫的重要天敌。目前,已确定性信息素化学成分的有3属4种盲蝽。这4种盲蝽性信息素的化学成分分别是显角微刺盲蝽Campylomma verbasci：丁酸丁酯和反-2-丁酸丁烯酯(16：1),Phytocoris californicus：乙酸己酯和反-2-乙酸龙脑脂(2：1),Phytocoris relativus：乙酸己酯和反-2-丁酸龙脑脂(2：1)及Lygocoris pabulinus：顺-9-二十五碳烯和顺-7-二十五碳烯(5：1)。相反,草盲蝽属Lygus昆虫的性信息素却难以鉴定。尽管从草盲蝽属昆虫中已分离鉴定20多种化合物,但至今没有1种或1个组分能成功地产生吸引该属雄虫的生物活性。     

牧草盲蝽对七种寄主植物不同挥发物的EAG和行为反应

【目的】研究牧草盲蝽Lygus pmtensis对寄主植物挥发物的EAG及趋向行为反应,为研发牧草盲蝽引诱剂或趋避剂策略提供科学依据。【方法】利用固相微萃取方法收集7种寄主植物包括木地肤Kochia prostrata (L.) Schrad.、灰绿藜Chenopodium glaucum、花椰菜Brassica oleracea L.var.botrytis L.、小白菜Brassica campestris L.ssp.chinensis Makino、田旋花Convolvulus arvensis L.、小藜Chenopodium serotinum L.、番茄Lycopersicon esculentum Mill.的挥发物,通过室内气相-质谱联用系统(GC-MS)进行挥发物的定性及定量分析,最终测定了9种候选特征挥发物的触角电位(EAG)反应和嗅觉趋向行为反应。【结果】7种寄主植物共鉴定到的化合物有31种,且种类和含量有较大差异,差异显著。9种候选特征挥发物均能引起牧草盲蝽雌、雄成虫的EAG反应。其中牧草盲蝽雌、雄成虫对壬醛的EAG反应绝对值最大,雌、雄虫对不同植物挥发物质EAG反应相对值均有显著差异,且对同种化合物雌虫的反应相对值均大于雄虫的反应,乙酸顺式-3-己烯酯和壬醛引发的EAG反应值差异显著;趋向行为测定中,牧草盲蝽雌虫对壬醛、金合欢烯、α-蒎烯、1-石竹烯、乙酸顺式-3-己烯酯、2-甲基-1-醇的大部分浓度的行为反应差异显著,雄虫仅对α-蒎烯、壬醛的部分浓度的行为反应差异显著。【结论】7种寄主植物的挥发物对牧草盲蝽雌、雄成虫具有不同EAG和趋向行为反应影响,候选气味化合物可以作为设计牧草盲蝽引诱剂组分进行田间害虫防控实践。     

寄主植物挥发物对梨小食心虫受孕雌虫的引诱作用初探

梨小食心虫Grapholita molesta(Busck),是一种世界性的蛀果害虫。利用产卵选择试验研究了15种寄主植物挥发物对梨小食心虫受孕雌虫的产卵引诱活性。室内试验表明:受孕雌虫对不同挥发物的产卵选择趋性不同,其中对叶醇和己酸丁酯表现出明显的产卵选择趋性。为验证寄主挥发物对受孕雌虫的实际诱捕效果,进行了田间诱捕试验。结果发现,挥发物中己酸丁酯、苯甲腈、叶醇、E-2-己烯醛以及乙酸己酯诱捕到的雌虫均为受孕雌虫,显著高于空白对照及其他物质,其中己酸丁酯的平均诱捕量最多,苯甲腈次之,E-2-己烯醛、乙酸己酯这两种物质的平均诱捕量分别为第三、第四,叶醇的诱捕量低于乙酸己酯,其余物质的诱捕量均较低。综合室内及田间试验结果发现,寄主植物挥发物对受孕雌虫的引诱作用也随它们之间的作用距离表现出一定的差异性。     

绿盲蝽八个普通气味受体基因的克隆及功能鉴定

【目的】本研究旨在克隆绿盲蝽Apolygus lucorum的气味受体基因,明确这些气味受体基因在绿盲蝽成虫不同组织中的表达水平及对主要寄主植物挥发物的电生理反应,为揭示绿盲蝽对寄主植物的识别机制提供理论基础。【方法】在绿盲蝽成虫触角转录组测序与分析的基础上,通过PCR技术克隆得到8个具有完整ORF的气味受体基因序列。用qPCR研究这8个基因在雌雄成虫不同组织(触角、无触角的头、胸、腹、足和翅)中的表达水平。然后通过爪蟾卵母细胞体外表达结合双电极电压钳技术测试这些气味受体对56种气味化合物的电生理反应。【结果】克隆得到了绿盲蝽8个气味受体基因AlucOR9, AlucOR16,AlucOR38, AlucOR53, AlucOR55, AlucOR56, AlucOR57和AlucOR58的cDNA全长序列(GenBank登录号:MN905538-MN905545)。这些气味受体含有7个跨膜结构域,且N末端位于胞内,C末端位于胞外,符合昆虫气味受体的典型特征。qPCR结果表明,这8个气味受体基因均在绿盲蝽成虫触角中高表达,而在其他组织中低表达,其中除AlucOR38外的其他7个气味受体基因在雌雄成虫触角间存在显著的表达差异。双电极电压钳记录结果显示,AlucOR57对其中15种气味化合物(苯甲醛、氧化石竹烯、庚醛、反-2-己烯醛、乙酸苯甲酯、桃金娘烯醛、4-乙基苯甲醛、乙酸壬酯、四氢芳樟醇、十三烷、反-3-己烯醇、2-丙烯酸丁酯、丙酸丁酯、乙酸辛酯和乙酸戊酯)有反应,其余7个气味受体对测试的全部气味化合物均无反应。【结论】AlucOR57对测试的一些气味化合物有反应,推测其在绿盲蝽的寄主识别过程中发挥重要作用;其他7个气味受体对测试气味化合物均无反应,其功能有待进一步研究。     

不同寄主植物对绿盲蝽成虫形态发育的影响

本文探讨了桃树、枣树、茶树及棉花4种不同寄主植物对绿盲蝽成虫形态发育的影响。通过田间采集4种寄主上绿盲蝽成虫,从体长、体宽、口针长、头宽和体重等指标比较不同寄主植物绿盲蝽的差异。结果表明,棉花绿盲蝽雌雄虫的体长、体宽、口针长、头宽均显著大于其他3种寄主植物。在体重上,雌虫和雄虫均表现出棉花＞茶树＞枣树＞桃树的规律,而且棉花绿盲蝽显著高于桃树绿盲蝽。试验表明,不同寄主植物对绿盲蝽成虫的形态发育有明显影响。在这4种寄主中,棉花极显著利于绿盲蝽成虫的形态发育。     

苹褐带卷蛾成虫对主要寄主植物挥发物的触角电位反应和行为反应

【目的】苹褐带卷蛾Adoxophyes orana是危害苹果、桃、梨、枣等果树的一种重要昆虫。近年来在陕西苹果和红枣产区发生面积逐年扩大,危害日趋严重。本研究旨在明确寄主植物挥发物在苹褐带卷蛾成虫嗅觉通讯中的作用,为开发植物源引诱剂提供基础数据。【方法】利用触角电位(electroantennogram, EAG)仪测定苹褐带卷蛾2日龄未交配雌、雄成虫对51种寄主植物挥发性化合物的EAG反应;利用本实验室开发的小型蛾类昆虫嗅觉行为测试装置测定苹褐带卷蛾成虫对15种具有显著EAG反应的挥发性化合物的行为反应。【结果】EAG测试结果表明,苹褐带卷蛾成虫对不同挥发性化合物的EAG反应相对值有显著差异,雌、雄成虫对顺 3 己烯 1 醇、反 2 己烯 1 醇、1 己醇、1 庚醇、己醛、反 2 己烯醛、庚醛、辛醛、壬醛、乙酸丁酯、乙酸异戊酯和乙酸 顺 3 己烯酯的EAG反应较强。此外,雄成虫对3 甲基 1 丁醇、1 戊烯 3 醇、苯甲醛、丁酸丁酯、乙酸乙酯、三甲基巴豆酸乙酯、己酸乙酯、丙酸丁酯、异戊酸 顺 3 己烯酯、苯甲腈和柠檬腈的反应较强。在待测的51种挥发性化合物中,苹褐带卷蛾成虫对29种化合物的EAG反应具有明显性别差异,除雌虫对(-)-α-水芹烯和莰烯的EAG反应显著高于雄虫外,雌虫对其他27种挥发性化合物的EAG反应显著低于雄虫。当测试的挥发性化合物剂量在0.02~20 μg时,随剂量的增大成虫的EAG反应变化不明显;当挥发物剂量在20~200 μg时,成虫的EAG反应随剂量的增大显著升高。嗅觉行为选择试验结果表明,雌成虫对己醛、庚醛、辛醛和乙酸 顺 3 己烯酯有明显的趋性,选择率均高于58%;雄成虫对1 己醇、庚醛、乙酸异戊酯和苯甲腈有明显的趋性。【结论】苹褐带卷蛾未交配雄成虫对寄主植物挥发性化合物的EAG反应较未交配雌成虫灵敏,1 己醇、己醛、庚醛、辛醛、乙酸 顺 3 己烯酯、乙酸异戊酯和苯甲腈对苹褐带卷蛾雌蛾或雄蛾具有明显的吸引作用,可以用于开发该害虫的植物源引诱剂。     

Sex Pheromones and Reproductive Isolation in Five Mirid Species

Mate location in many mirid bugs (Heteroptera: Miridae) is mediated by female-released sex pheromones. To elucidate the potential role of the pheromones in prezygotic reproductive isolation between sympatric species, we investigated differences in the pheromone systems of five mirid species, Apolygus lucorum, Apolygus spinolae, Orthops campestris, Stenotus rubrovittatus and Taylorilygus apicalis. GC/MS analyses of metathoracic scent gland extracts of virgin females showed that all five species produced mixtures of hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal, but in quite different ratios. (E)-2-hexenyl butyrate was the major component of A. spinolae, while hexyl butyrate was the most abundant component in the pheromone blends of the other four species. In addition to the three compounds, a fourth component, (E)-2-octenyl butyrate, was present in the gland extracts of A. lucorum and T. apicalis females. Field tests suggest that the ternary blends of hexyl butyrate, (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal as found in the extracts of the females of each species do not inhibit attraction of conspecific males but ensure species-specificity of attraction between A. lucorum, O. campestris and T. apicalis. Furthermore, (E)-2-octenyl butyrate was essential for attraction of A. lucorum and T. apicalis males, but strongly inhibited attraction of male A. spinolae, O. campestris and S. rubrovittatus. The combined results from this study and previous studies suggest that the minor component and pheromone dose in addition to the relative ratio of the major components play an important role in reproductive isolation between mirid species.     

Performance of polyethylene tubes as pheromone lures for the sorghum plant bug, Stenotus rubrovittatus (Hemiptera: Heteroptera: Miridae)

The sorghum plant bug, Stenotus rubrovittatus (Matsumura) (Hemiptera: Heteroptera: Miridae), is a pest that infests rice in many regions of Japan. Three sex attractant pheromone components—hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal—were identified in S. rubrovittatus. Because the longevity of a synthetic rubber septum dispenser is not sufficient for it to be an effective S. rubrovittatus pheromone lure, the performances of an alternative pheromone dispenser—a polyethylene tube—was examined. Hexyl butyrate and (E)-2-hexenyl butyrate are essential components of S. rubrovittatus male attraction, and the application of (E)-4-oxo-2-hexenal strongly enhanced the attractiveness of such “tube-type” lures. A 5:1:10 blend of hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal was found to be the best blend ratio for male attraction in the tube-type lures. Tube-type lures attracted more males than rubber lures. Furthermore, the attractiveness of the tube-type lures was maintained for more than 28 days in the field. These results suggest that tube-type lures made of polyethylene plastic are suitable for monitoring S. rubrovittatus in fields.     

Behavioural responses of wheat stem sawflies to wheat volatiles

1 Adult wheat stem sawflies Cephus cinctus, pests of cultivated cereals that also infests wild grasses, migrate into wheat fields where they oviposit in elongating, succulent stems.
2 Volatiles released by wheat plants at susceptible stages were analyzed to determine potential semiochemical compounds. Seven major compounds were identified and quantified.
3 A Y-tube bioassay was developed to evaluate upwind orientation of adult sawflies in response to an airstream that passed over elongated wheat plants. The bioassay was also conducted with synthetic volatile compounds. The compounds were tested using a range of concentrations spanning those identified in the airstream passing over wheat plants.
4 A significant number of adult females were attracted to wheat plants when given a choice of either purified air or the air passing over plants.
5 A significant number of female C. cinctus were attracted to ( Z )-3-hexenyl acetate, β-ocimene, and ( Z )-3-hexen-1-ol, but were repelled by 6-methyl-5-hepten-2-one. Females did not respond to ( E )-2-hexenal, or ( E )-2-hexenyl acetate. The behavioural responses were concentration dependent; the highest tested concentration of ( Z )-3-hexenyl acetate was repellent to females of this species.
6 Adult males did not discriminate between air passing over wheat plants and air from a purified airstream. Males did not respond to any tested synthetic compound at any concentration.
7 The present study demonstrates for the first time that adult females of wheat stem sawfly display innate behaviours in response to synthetic volatiles. These results provide a basis for the potential development of resistant wheat varieties and for the development of semiochemically-based pest management.     

Identification of female sex pheromone of a plant bug,Adelphocoris fasciaticollis Reuter (Hemiptera: Miridae)

The plant bug, Adelphocoris fasciaticollis, has begun to resurge and become a key pest for cotton and alfalfa in northern China, along with the widespread cultivation of Bt cotton. To control this plant bug without pesticides, we attempted to develop a new approach by utilizing sex pheromone. The sex pheromone components from the whole‐body extracts were analysed by GC‐MS and gas chromatography–electroantennogram detector analysis (GC‐EAD). (E)‐4‐Oxo‐2‐hexenal and hexyl butyrate, identified as the major components in the extracts of female bugs, elicited strong EAD responses. Field tests indicated that either (E)‐4‐oxo‐2‐hexenal or hexyl butyrate attracted few A. fasciaticollis males and was significantly less active than virgin females and the binary blend. Their ratio was optimized to be 1 : 11. Our results could expand acknowledge of the pheromone of mirids and provide novel approaches to monitor and control this plant bug without pesticides.     

Electrophysiological and behavioral responses of Helicoverpa assulta (Lepidoptera: Noctuidae) to tobacco volatiles

The Oriental tobacco budworm moth, Helicoverpa assulta (Guenée) (Lepidoptera: Noctuidae), is a serious pest on tobacco in China. The flowering stage of the host plant is one of the most attractive stages to H. assulta for feeding and oviposition. Nine electrophysiologically active compounds in tobacco headspace at flower stage were detected by gas chromatography?Celectroantennographic detection (GC?CEAD). These compounds were subsequently identified by gas chromatography-mass spectrometry (GC?CMS) as (E)-??-ocimene, octanal, (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, nonanal, (Z)-3-hexenyl-2-methyl butyrate, decanal, linalool, and (E)-??-caryophyllene. The synthetic blend containing nine of the above compounds attracted mated H. assulta females from a distance by upwind oriented flight. Selected subtraction assays showed that the 4-component mixture of (E)-??-ocimene, (Z)-3-hexenyl acetate, nonanal, and (E)-??-caryophyllene elicited equivalent levels of attraction as the 9-component mixture. The removal of any of the four compounds from the 4-component blend resulted in a significant decrease in female upwind flight behavior.     

Efficiency of volatile baited sticky traps for the Tarnished Plant Bug (Lygus lineolaris) in strawberry fields

Insecticides have adverse effects on human health and the environment. Thus, the development of non-chemical replacement to manage insect pests is urgent. An alternative is to bait sticky traps with attractive insect sex pheromones or plant volatiles. In Quebec, the tarnished plant bug (Lygus lineolaris) is a major insect pest. We tested the efficiency of sex pheromones (mixture of hexyl butyrate (HB), (E)-2-hexenyl butyrate (E2HB) and (E)-4-oxo-2-hexenal (KA)) and sunflower (Helianthus annuus) volatiles (pinene, sabinene and phenylacetaldehyde) as sticky trap baits for the tarnished plant bug in strawberry fields of the Laurentians in Southern Québec, Canada. The pheromones decreased the number of tarnished plant bug caught in the traps compared to a control. The sunflower volatile did not have any effect on the number of individuals caught in the traps. Different Lygus species use HB, E2HB and KA in different ratios for sexual signals and alarm signals and for species recognition. GC-MS analysis of the sex pheromone bait revealed that the ratios between the three main compounds did not match the intended ratio for the L. lineolaris species. This mismatch probably explains our results. Individuals were not attracted to sunflower volatiles. Our results point to the difficulty of manufacturing and using sex pheromones as baits. Future work should assess the effect of several pheromone ratios.     

A photoaffinity-labeled green leaf volatile compound 'tricks' highly selective and sensitive insect olfactory receptor neurons

The sex pheromone of the scarab beetle, Phyllopertha diversa, is emitted by females and specifically detected by olfactory receptor neurons in the male and female antennae. Single sensillum recordings showed that, in contrast to the less sensitive pheromone sensilla in females, olfactory receptor neurons in the male antennae had a low threshold (1 ng), which rivals those of moths. The male and female antennae also possessed olfactory receptor neurons specific for the detection of floral and green leaf volatile compounds. Detectors for the green leaf volatile (Z)-3-hexenyl acetate had a threshold (10 pg) far below the sensitivity of the pheromone-detecting machinery. In addition, these neurons showed a remarkable selectivity even when challenged with related compounds at 10000-fold higher concentrations. Surprisingly, a diazo analog, (Z)-3-hexenyl diazoacetate, elicited slightly higher nervous activity than the natural ligand in the neurons specific and selective for (Z)-3-hexenyl acetate. The inability of the green leaf volatile-detecting machinery to discriminate the photoaffinity-labeled compound from the natural product indicates that the synthetic ligand interacts with odorant-binding protein, odorant receptor and odorant-degrading enzyme as does the cognate ligand.     

Electrophysiological and behavioral responses of a parasitic wasp to plant volatiles induced by two leaf miner species

In the present study, Y-tube olfactometric assays demonstrated that headspace volatile extracts collected from leaf miner-damaged, or artificially damaged, bean plants were more attractive to naive females of the parasitoid insect Opius dissitus than those collected from healthy plants. Headspace extracts from both Liriomyza huidobrensis and Liriomyza sativae second-instar larvae-damaged beans were analyzed by coupled gas chromatography-electroantennographic detection (GC-EAD). Of nine EAD-active volatiles identified, (3E)-4,8-dimethyl-1,3,7-nonatriene, (3Z)-hexenyl acetate, (syn)-2-methylpropanal oxime, and (syn)-2-methylbutanal oxime were the most abundant compounds that evoked significant electroantennogram (EAG) responses. Compounds (3Z)-hexen-1-ol, (anti)-2-methylbutanal oxime, linalool, beta-caryophyllene, and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene also elicited clear EAG responses but were present in smaller amounts. Choice experiments in a Y-tube olfactometer indicated that synthetic versions of (3Z)-hexen-1-ol, 2-methylpropanal oxime, 2-methylbutanal oxime, 3-methylbutanal oxime, linalool, (E,E)-alpha-farnesene, and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were attractive individually, while (3Z)-hexenyl acetate and (3E)-4,8-dimethyl-1,3,7-nonatriene were unattractive at concentrations similar to those obtained from the headspace collection. Moreover, a blend of nine EAD-active volatiles was significantly more attractive relative to hexane (solvent). A mixture of oximes, tereponids, and green leaf volatiles may facilitate host location by female O. dissitus.