Semiochemicals from Fungal Associates of Bark Beetles May Mediate Host Location Behavior of Parasitoids

In laboratory olfactometer bioassays, females of two hymenopteran parasitoid species, Roptrocerus xylophagorum (Ratzeburg) (Hymenoptera: Pteromalidae) and Spathius pallidus (Ashmead) (Hymenoptera: Braconidae), were attracted to odors from bark or bolts of loblolly pine, Pinus taeda L., colonized by bluestain fungi (genus Ophiostoma) associated with the parasitoids' bark beetle hosts. Mock-inoculated bolts and bark were less attractive or unattractive in these bioassays. Bark infested with host larvae that lacked their fungal and other normal microbial associates was attractive to R. xylophagorum females, but was less so than bark infested with larvae possessing their normal complement of associated microbes. In contrast, in oviposition bioassays, R. xylophagorum females spent approximately equal time searching, made similar numbers of oviposition attempts, parasitized similar percentages of hosts, and laid similar numbers of eggs in bark fragments infested with either associate-free or associate-bearing host larvae. Furthermore, in field bioassays using bluestain-inoculated or mock-inoculated loblolly pine bolts as sources of attractants, the numbers of parasitoids attracted by the two treatments did not differ significantly and the two treatments were less attractive than bolts naturally infested with bark beetle larvae. Whereas our laboratory olfactometer data suggest that bark beetle fungal associates may enhance attraction of some parasitoids, our bioassays with associate-free hosts indicate that associate-produced are not required for short-range host location and parasitization. In addition, our field trials indicated that long-range attraction of parasitoids to the host-fungi-tree complex is not caused simply by an interaction between bluestain fungi and tree tissues.     

Effects of Volatile Compounds Emitted by Protea Species (Proteaceae) on Antennal Electrophysiological Responses and Attraction of Cetoniine Beetles

Evolutionary shifts in pollination systems within a plant genus are commonly associated with changes in floral scent, reflecting selection mediated through the sensory systems of various pollinators. The most common cetoniine beetle pollinator of grassland Protea species in South Africa, Atrichelaphinis tigrina, previously has been shown to have a strong preference for the fruity floral scent of these plants over the weak scent of their bird-pollinated congeners. However, it is not known which of the many compounds found in the scent of beetle pollinated Protea species play a role for pollinator attraction. Electroantennograms (EAG) from A. tigrina beetles were recorded in response to 15 compounds emitted by Protea flower heads. EAG responses to all 15 compounds were significantly greater than those to the paraffin solvent in which they were diluted. The greatest responses were observed for aromatics (anisole, methyl benzoate, methyl salicylate, benzaldehyde) followed by the monoterpene β-linalool, which can comprise up to 66 % of fruity Protea scents. Five compounds that elicited EAG responses (benzaldehyde, β-linalool, (E/Z)-linalool oxide (furanoid), methyl benzoate, and methyl salicylate) were tested in commercially available yellow bucket traps in the field to test their attractiveness to beetles. Traps baited with methyl benzoate, β-linalool, (E/Z)-linalool oxide (furanoid), and methyl salicylate caught significantly more insects than did those containing paraffin only. Methyl benzoate also was more specifically attractive to A. tigrina than was (E/Z)-linalool oxide (furanoid) and paraffin baited controls. A second field experiment using a combination of linalool vs. paraffin baited yellow or green traps showed that trap color had a significant effect on the number of trapped beetles. Yellow traps yielded a ten-fold higher number of insect catches than did green traps. However, the combination of yellow color and the scent compound linalool yielded the highest number of catches. This study has shown that the cetoniine beetle A. tigrina can detect a variety of floral compounds and is attracted to compounds comprising a large proportion of the blend that makes up fruity Protea scents, adding support for the hypothesis that change in scent chemistry during the shift from bird to cetoniine beetle pollination in this genus were mediated by beetle sensory preferences.     

挥发性有机物的控制技术进展

大气与室内中的挥发性有机物(VOCs)对生态环境和人类健康都具有较大的危害,研究VOCs的控制具有重要意义。在介绍VOCs的特点、危害的基础上,详细介绍了多种VOCs的末端控制处理方法和技术,包括吸附法、吸收法、冷凝法、膜分离法、生物控制法、燃烧(催化燃烧)法、低温冷离子控制法、光催化法等方法的研究进展,并比较了不同方法在对设备要求、稳定性、操作难易等方面的优缺点。     

挥发性有机物的排放管理与控制

挥发性有机物的挥发性更容易,对其进行控制与其他的大气污染物有很大区别。基于对挥发性有机物排放特点的分析,提出了主要的控制途径。     

Disruption by Conophthorin of the Kairomonal Response of Sawyer Beetles to Bark Beetle Pheromones

Antennally active nonhost angiosperm bark volatiles were tested for their ability to reduce the response of three common species of coniferophagous wood-boring Cerambycidae to attractant-baited multiple funnel traps in the southern interior of British Columbia. Of the nonhost volatiles tested, only conophthorin was behaviorally active, disrupting the attraction of sawyer beetles, Monochamus spp., to traps baited with the host volatiles -pinene and ethanol and the bark beetle pheromones ipsenol and ipsdienol. Conophthorin did not affect the attraction of sawyer beetles to the host kairomones -pinene and ethanol in the absence of bark beetle pheromones, nor did it have any behavioral effect on adults of Xylotrechus longitarsis, which were not attracted to bark beetle pheromones. These results indicate that conophthorin does not act as a general repellent for coniferophagous Cerambycidae, as it seems to do for many species of Scolytidae, but has the specific activity of disrupting the kairomonal response of sawyer beetles to bark beetle pheromones.     

Characterization of Volatile Organic Compounds Emitted by Barley (Hordeum vulgare L.) Roots and Their Attractiveness to Wireworms

Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here on the identification of VOCs emitted by barley roots (Hordeum vulgare L.). Twenty nine VOCs were identified from isolated 21-d-old roots. The detection was dependent on the medium used for root cultivation. We identified 24 VOCs from 7-d-old roots when plants were cultivated on sterile Hoagland gelified medium, 33 when grown on sterile vermiculite, and 34 on non-sterile vermiculite. The major VOCs were fatty acid derived compounds, including hexanal, methyl hexanoate, (E)-hex-2-enal, 2-pentylfuran, pentan-1-ol, (Z)-2-(pentenyl)-furan, (Z)-pent-2-en-1-ol, hexan-1-ol, (Z)-hex-3-en-1-ol, (E)-hex-2-en-1-ol, oct-1-en-3-ol, 2-ethylhexan-1-ol (likely a contaminant), (E)-non-2-enal, octan-1-ol, (2E,6Z)-nona-2,6-dienal, methyl (E)-non-2-enoate, nonan-1-ol, (Z)-non-3-en-1-ol, (E)-non-2-en-1-ol, nona-3,6-dien-1-ol, and nona-2,6-dien-1-ol. In an olfactometer assay, wireworms (larvae of Agriotes sordidus Illiger, Coleoptera: Elateridae) were attracted to cues emanating from barley seedlings. We discuss the role of individual root volatiles or a blend of the root volatiles detected here and their interaction with CO₂ for wireworm attraction.     

Diversity of the Volatile Organic Compounds Emitted by 55 Species of Tropical Trees: a Survey in French Guiana

Volatile organic compounds (VOCs) are produced by a broad range of organisms, from bacteria to mammals, and they represent a vast chemical diversity. In plants, one of the preeminent roles of VOCs is their repellent or cytotoxic activity, which helps the plant deter its predators. Most studies on VOCs emitted by vegetative parts have been conducted in model plant species, and little is known about patterns of VOC emissions in diverse plant communities. We conducted a survey of the VOCs released immediately after mechanical damage of the bark and the leaves of 195 individual trees belonging to 55 tropical tree species in a lowland rainforest of French Guiana. We discovered a remarkably high chemical diversity, with 264 distinct VOCs and a mean of 37 compounds per species. Two monoterpenes (α-pinene and limonene) and two sesquiterpenes (β-caryophyllene and α-copaene), which are known to have cytotoxic and deterrent effects, were the most frequent compounds in the sampled species. As has been established for floral scents, the blend of VOCs is largely species-specific and could be used to discriminate among 43 of the 55 sampled species. The species with the most diverse blends were found in the Sapindales, Laurales, and Magnoliales, indicating that VOC diversity is not uniformly distributed among tropical species. Interspecific variation in chemical diversity was caused mostly by variation in sesquiterpenes. This study emphasizes three aspects of VOC emission by tropical tree species: the species-specificity of the mixtures, the importance of sesquiterpenes, and the wide-ranging complexity of the mixtures.     

化工区域挥发性有机物污染控制研究

化工园区是挥发性有机物一个重要排放源,对区域空气质量产生重要影响,因此,做好化工区域挥发性有机物污染防控十分重要。根据挥发性有机物排放特点,结合上海市金山卫化工集中区环境综合整治工作,从政策法规、监测技术、环境管理、末端治理等层面,提出化工区域挥发性有机物污染控制的对策和建议。     

挥发性有机污染物(VOCs)监测方法及治理研究

随着经济的不断发展以及各个行业的竞争愈演愈烈,部分企业在发展的过程中为了追求利益的最大化,往往忽视了环境的重要性,特别是化工厂产生的具有挥发性的有机污染物(VOCs),这种污染物普遍存在于空气中,对于空气的质量有些消极的影响。     

合成橡胶装置挥发性有机物排放治理措施

介绍中国石油独山子石化公司乙烯厂丁苯橡胶装置挥发性有机物(VOCs)排放治理措施。通过有针对性地对装置压力控制模式、处理工艺、停工检修过程、排放口治理、后处理设备、溶剂系统运行条件、密封面等方面实施环保控制及优化措施,现场VOCs排放减少,环境明显改善。     

挥发性有机物的气相色谱分析研究

挥发性有机物(Volatile Organic Compounds,VOCs)是强挥发性有机化学物质的总称,挥发性有机物在常温下,是一种逸散性排放的物质,对空气和环境的污染比较严重,对人体的健康也会产生极大的威胁.挥发性有机物主要来源石油化工产品、汽车尾气、化学溶剂、涂料油漆、废物处理等等,因此对挥发性有机物的污染受到越来越多的人重视.通过利用气相色谱对空气和室内进行测量、分析、研究.     

VOCs无组织排放估算方法和控制标准初探

无组织排放是挥发性有机物(VOCs)进入大气环境的重要途径,控制难度也最大。对当前VOCs无组织排放的估算模型进行了总结和比较,对无组织排放的控制标准进行了探讨。     

微捕集在GCMS测定痕量有机污染物中的应用

微捕集技术可作为连接样品与GCMS之间的桥梁,使分析过程实现了样品的采样-浓缩-进样分析在线操作,具有操作简单、快速、无需溶剂,回收率高,样品预处理时间短,分析运行成本低等特点,可用于大气样品中痕量有机污染物的全自动分析。     

纤维板工业挥发性有机物排放特征及防治措施

以典型干法纤维板生产企业为研究对象,通过典型企业调研和现场实测,阐明干法纤维板的工艺流程及生产过程挥发性有机物(VOCs)的重点排放源及排放特征,提出了实施行业排放标准、推行清洁生产、降低游离甲醛含量及末端治理等一系列措施,建立源头预防、过程监管、末端治理一体化综合管控体系。     

低温等离子体处理挥发性有机物的研究进展

低温等离子体技术在处理挥发性有机物(VOCs),特别是在对空气中低含量的VOCs的处理中,具有独特的作用.概述了低温等离子体降解VOCs的基本原理及等离子体反应器结构;综述了低温等离子体技术以及和催化剂联合作用在处理VOCs中的应用;并讨论了低温等离子体处理VOCs的进一步研究方向及其应用前景.     

活性炭对挥发性有机化合物的吸附回收研究进展

介绍了挥发性有机化合物(VOCs)的来源、种类、危害、回收意义以及常见的回收技术。VOCs是指除CO、CO₂、H₂CO₃、金属碳化物、金属碳酸盐和碳酸铵外,所有参加大气光化学反应的碳化合物,主要来源于以石化产品为主要燃料的交通工具产生的尾气和工业生产过程中产生的废气等,会对环境造成严重危害。目前主要的处理技术有破坏技术和回收技术,其中活性炭吸附技术已经成为环保领域研究的热点。重点介绍了活性炭对芳香烃、脂肪烃、卤代烃、醇类、醛类、酮类、醚类和酯类这几种主要的VOCs的吸附回收技术及研究进展。     

Succession of Dung-Inhabiting Beetles and Flies Reflects the Succession of Dung-Emitted Volatile Compounds

Chemical cues, such as volatile organic compounds (VOCs), are often essential for insects to locate food. Relative to the volume of studies on the role of VOCs in insect-plant relationships, the role of VOCs emitted by dung and carrion in mediating the behavior of insect decomposers is understudied. Such relationships may provide a mechanistic understanding of the temporal axis of community assembly processes in decomposing insect communities. We focused on the temporal succession of volatiles released by cow dung pats and the potential influence on dung-inhabiting insects. Using gas chromatography/mass spectrometry we identified and quantified VOCs released from dung 1-h, and 1, 2 3, 5, and 7 d-old. We then related changes in VOCs to successional patterns of dung-inhabiting beetles and flies. We detected 54 VOCs which could be assigned to two successional groups, with chemical turnover in dung changing around day 2. The early successional group consisted primarily of aliphatic alcohols and phenols, and the late one of aliphatic esters, nitrogen- and sulfur-bearing compounds. Flies were predominately associated with the early successional group, mainly with 1-butanol. Beetles were associated predominately with the late-successional group, mainly with dimethyl trisulfide. This association between insect and chemical successional patterns supports the idea that habitat filtering drives the community assembly of dung-inhabiting insects on an aging resource. Moreover, the affinity of both insect groups to specific VOC groups provides a mechanistic explanation for the predictability of successional patterns found in dung-inhabiting insect communities.

     

油品储运行业挥发性有机物排放控制技术分析

本文详细分析我国目前油品储运行业中挥发性有机物排放环节以及控制技术。     

P＆T—GC—MS测定饮用水中痕量有机污染物

建立了吹扫捕集与气相色谱-质谱联用(P&T-GC-MS)测定饮用水中8项挥发性有机污染物的分析方法.水样的加标回收率在90%～110%之间,其相对标准偏差基本小于5.0%,该方法已成功地用于饮用水中挥发性有机污染物的测定,结果令人满意.