水分胁迫对植物与植食性昆虫互作的影响

水分作为一种重要的环境因子,对陆地生物生长发育有着至关重要的作用。随着全球气候变暖,异常天气频发,水分胁迫也成为了影响农作物及其害虫生长发育的重要逆境胁迫。本文从水分胁迫对植食性昆虫的直接和间接影响进行阐述:从湿度、降雨量和土壤含水量角度讨论了水分胁迫对昆虫的直接影响;从水分影响植物和天敌角度,讨论了水分胁迫对植物-植食者性昆虫-天敌三营养阶层互作的间接影响,以期为理解农业害虫发生机制及其可持续治理决策提供研究信息和理论参考。     

植食性昆虫选择寄主植物的奥秘

在自然的情况下,每一种植食性昆虫都各有其一定的寄生范围,单食性昆虫只取食某种植物,而多食性昆虫则选取固定的几十种到几百种植物。从识别的过程来说,昆虫不象高等动物那样,对食物的认识靠传教、靠经历、甚至靠思维;对昆虫视觉生理研究也表明：植食性昆虫的视觉在...     

寄主植物对植食性昆虫与昆虫杆状病毒互作的调控

植物与植食性昆虫、植食性昆虫与昆虫杆状病毒之间的两营养级互作关系,至今已有超过半个世纪的研究历史,但这三营养级的互作研究,在近20年才引起科学家的兴趣。在查阅并理解国内外相关文献的基础上,本文主要从植物的物理性状、营养物质和次生代谢物质三个角度出发,剖析植物调控昆虫响应病毒感染的生态生理及免疫机制,阐明植物影响病毒增殖、病毒组分及其感染过程和致病力的机理。此外,本文就植物、植食性昆虫和昆虫杆状病毒互作的研究方向、研究方法,进行了初步展望,以期为更好研究多营养级共存系统的食物网关系,提供理论依据。     

诠释植食性昆虫是怎样选择食料植物的

昆虫对食料植物的选择,是各种昆虫行为最为明显的表现,和人类的农林生产有密切的关系。在蝗虫、甲虫等昆虫种类中,幼虫和成虫常取食相同的植物,但鳞翅目、双翅目等昆虫的幼虫的食料植物与成虫的不同,常在成虫产卵时决定幼虫取食的植物。昆虫对植物的选择依靠感觉器官的功能,而植物除合有昆虫所需的营养成分外,还合有种类特异性的代谢次生物质,它们对昆虫产生感觉刺激,是昆虫对植物进行选择的主要因素。有些昆虫在选择植物时嗅觉、味觉、触觉起着比较严格的限制作用,称为寡食性或单食性的种类。另一些昆虫虽然感觉作用也很灵敏,但适应的范围较广,能取食多种植物,称为多食性昆虫。以飞蝗、棉铃虫与烟青虫为例,介绍了昆虫的感觉器官和神经系统在选择食料植物时所起的作用。     

西双版纳热带雨林次生演替中昆虫群落的动态研究

通过对西双版纳热带雨林,砍伐后４块处于次生性演替恢复阶段,不同年代林中,所设固定样地中昆虫群落的定时、定点和定量采集观测,对群落中昆虫的数量、种类、群落的多样性、优势度和稳定性进行了分析比较。从年度变化看：昆虫个体数和植食性昆虫数在雨季是最大的。优势度在演替阶段后期是雨季大于旱季,而在前期则是旱季大于雨季。多样性和均匀性在演替后期是旱季大于雨季,而演替前期则是雨季大于旱季。从演替年代变化看：随着演替年代的递增,昆虫群落的多样性、均匀性和稳定性有增加的趋势,而昆虫数量和植食性昆虫数量减少的趋势。对昆虫群落稳定性的讨论,试引入“变异系数”进行讨论。     

植食性昆虫的嗅觉选食过程及其机制研究进展

植食性昆虫的嗅觉在其选择食物的过程中发挥了重要的作用,它能通过对植物挥发物的感受来定向和定位食物源并产生趋近行为,进而根据特殊的化合物或者多种化合物的特异浓度组合来区分寄主和非寄主植物.在这个过程中,昆虫嗅觉器官上相关的嗅觉感受蛋白被植物挥发物激活,形成特异的嗅觉感受通路,在行为上调控昆虫嗅觉选食的能力.本文主要从植食...     

紫外B辐射增强对植食性昆虫的影响

大气平流层臭氧的破坏直接增强了到达地面的太阳紫外线,特别是紫外B辐射的强度。紫外B辐射增强将对生态系统产生深刻的影响。本文综述了近年来紫外B辐射增强对昆虫影响的研究,分析了紫外B辐射增强可能产生的对植食性昆虫的直接和间接影响及其机制,就紫外B辐射增强对昆虫影响方面迫切需要阐明的一些问题进行了讨论。     

植物与植食性昆虫化学互作研究进展

植物与植食性昆虫之间存在着复杂的化学相互作用。一方面,当遭受植食性昆虫为害时,植物能识别植食性昆虫相关分子模式,触发早期信号事件和激素信号转导途径,并由此引起转录组与代谢组重组、直接和间接防御化合物含量升高,最后提高对植食性昆虫的抗性。另一方面,植食性昆虫也能识别植物的防御反应,并能通过分泌效应子、选贮、解毒以及降低敏感性等反防御措施抑制或适应植物的化学防御。深入剖析植物与植食性昆虫的化学互作,不仅可在理论上丰富对昆虫与植物互作关系的理解,而且可在实践上为作物害虫防控新技术的开发提供重要的理论与技术指导。     

植物干旱胁迫对植食性昆虫及其天敌的影响

全球正经历以变暖为主要特征的气候变化,由此带来的干旱将对农业生态系统造成重要影响。本文综述了干旱胁迫下寄主植物对植食性昆虫及其天敌影响的国内外最新研究进展。在干旱胁迫下,寄主植物物理性状、营养状况和次生代谢物质等均发生变化,这些变化导致植食性昆虫的生存环境和营养物质的获取等方面发生改变,从而影响了害虫生长发育和种群动态。干旱胁迫还导致寄主物候变化与昆虫发生不同步,使害虫缺乏食物。另外干旱也会引起植食性害虫天敌的种群发生变化,从而对植食性昆虫种群数量产生间接的影响。     

虫害诱导植物挥发物(HIPVs)对植食性昆虫的行为调控

虫害诱导植物挥发物(herbivore induced plant volatiles,HIPVs)具有植物种类、品种、生育期和部位的特异性,也具有植食性昆虫种类、虫龄、为害程度、为害方式和其他一些环境因子的特异性。由于其释放量明显大于健康植株,因此更易被天敌、害虫以及邻近的植物等所利用,从而调节植物、植食性昆虫与天敌三者之间的相互作用关系,增强植物在自然界的生存竞争能力。本文对HIPVs在植食性昆虫寄主定位行为中的作用、HIPVs对植食性昆虫的种群调控功能及其应用现状2个方面加以综述,并在展望中对目前研究中存在的一些问题进行了探讨。     

鲁西北草坪植食性昆虫的种类组成及危害现状

普查了鲁西北地区草坪植食性昆虫的种类 ,共发现草坪植食性昆虫及其它有害动物 5 5种 ,其中成灾种类 2 0多种 ,例如危害禾本科草坪的草地螟、赤须盲蝽、麦牧野螟、灰飞虱和叶蝉类、危害白三叶草的烟蓟马、甜菜白带野螟、豆卷叶螟和多种盲蝽象以及在两类草坪上均造成严重危害的大青叶蝉、黄地老虎和蛴螬类等 ,首次报道了小蓑蛾和梨冠网蝽可对三叶草造成危害。研究了草坪害虫的分布特点及主要害虫的消长规律 ,发现不同区域、不同栽培环境害虫种类组成不同 ;同一区域在不同年份、不同季节优势种群不同。并针对草坪害虫的时空分布提出了几点治理对策     

Resistance of Pteridium aquilinum to attack by non-adapted phytophagous insects

Fresh bracken Pteridium aquilinum L. Kühn or crude bracken extracts deterred 9 non-adapted phytophagous insect species from feeding or settling. Feeding deterrent activity to 5 out of 7 insect species was present in crude bracken extracts at all times over the growing season and was significantly highest in May. Sequential isolation and purification of deterrents indicated that the sesquiterpene pterosin F (6-chlorethyl-2,5,7-trimethyl-indan-1-one) occurred in sufficiently high concentrations in late May/early June bracken frond (24–28 mg/kg fresh wt) to be partially responsible for the deterrent effects of crude bracken extracts to two insect species. A number of other fractions had feeding deterrent activity, but these were not characterized or quantified.     

Mapping and characterization of mangrove plant communities in Hong Kong

Ecological surveys were carried out to investigate the distribution and characterization of remaining mangrove stands in Hong Kong. The field studies indicate that 43 mangrove stands, excluding Mai Po Nature Reserve, still remained along the coastline of Hong Kong despite tremendous reclamation and development which occurred in the past 40 years. Most mangrove stands were found in Deep Bay (western part)and Sai Kung District (eastern coasts). The total areas occupied by these mangrove stands were 178 ha,varying from a very small stand (with 1–2 mangrove shrubs) to fairly extensive mangroves in Deep Bay (> 10 ha). It appeared that mangrove stands located in Deep Bay area were larger than those in the eastern coasts. Twenty plant species were identified from these stands, with 13 being exclusive or associate mangrove species. The major constituent species were Kandelia candel, Aegiceras corniculatum, Excoecaria agallocha and Avicennia marina. Rare species such as Heritiera littoralis were only found in a few mangrove stands. Out of the 43remaining mangrove stands, 23 were more worthwhile for conservation and their plant community structures were further investigated by transect and quadrat analyses. The importance values (sum of relative abundance,frequency and dominance) show that K. candel was the most dominant species. Species richness and Simpson's indices together with tree height, tree density and canopy area fluctuated significantly between mangrove stands. These values were used to prioritize the conservation potential of the remaining mangrove stands in Hong Kong. This revised version was published online in August 2006 with corrections to the Cover Date.     

Structure of the phytophagous insect fauna of Onopordum thistles in the northern Mediterranean basin

Thistles of the genus Onopordum (Asteraceae: Cardueae) have become serious weed problems in parts of Australia and North America following introduction from their native Eurasian ranges, and are the target of a biological control programme in Australia. This paper analyses the results of three separate surveys of insects feeding and breeding on thistles of the genus Onopordum in the Mediterranean region. Of the 129 species found feeding, 74 species also bred on these thistles. Endophages comprised 54% of the breeding insects, with species that fed in the capitula and within the rosette crown/root area predominating. The Coleoptera and Hemiptera were the dominant endophage and ectophage taxa, respectively. Differences in the Onopordum fauna were noted between host species and between geographic regions, but this was largely due to the generalist component of the fauna. Onopordum specialists showed little variability across regions or between different species within the host genus. On comparing the fauna of Onopordum with that of other thistle genera, it was suggested that plant-herbivore interactions between Onopordum and its fauna are less highly evolved, in that there is less host specialization and a lesser degree of niche partitioning. This appears to be related to the low rate of speciation and habitat specialization within the host genus itself. The potential of certain genus-specific insects as biological control agents for Onopordum spp. is discussed. It is argued that the absence of a high degree of niche specialization could favour successful biological control, as the agent would be capable of inflicting damage over a wider range of resource gradients.     

Studies on Australian mangrove algae. III. Victorian communities: Structure and recolonization in western port bay

The algal communities associated with Avicennia pneumatophores in Western Port Bay, Victoria, Australia (145°E:38°S) are composed primarily of the red algae Bostrychia, Caloglossa and Catenella. Trends from seaward to landward indicate a decrease in frequency of occurrence, relative cover, and mean absolute biomass for all algal genera but differing trends occur for each genus in terms of relative biomass, and this is reflected in associated pattern analyses. In terms of vertical community structure, all algae occur most frequently in the 5–10 cm segment above mudline, whereas above 20 cm, values for all measured parameters decline. Vertical structure in the seaward and landward regions is compared, but pattern analyses indicate that no biologically distinctive pattern is present. Deliberately denuded pneumatophores quickly become recolonized; greater algal development occurs above 10 cm above the mudline than below 10 cm, and the new community is differently structured.     

蜜粉源植物对天敌昆虫的作用及其在生物防治中的应用

寄生性和捕食性天敌昆虫成虫普遍存在通过取食蜜粉源植物补充营养的行为,这可不同程度地促进天敌昆虫性成熟、延长其寿命、提高其生殖力或寄生率,以及搜寻寄主效率和子代雌性比率,从而显著提高天敌昆虫在生物防治中的控害能力和效果。蜜粉源植物花的结构及植物对天敌昆虫产生的嗅觉、视觉信号和花蜜花粉对天敌昆虫产生的味觉信号又显著影响天敌昆虫选择蜜粉源植物的行为和结果。但是,蜜粉源植物也可成为害虫的补充营养植物,从而提高害虫的为害能力。因此,需深入研究不同蜜粉源植物对天敌昆虫及害虫的作用,趋利避害,才可能应用蜜粉源植物成功调控天敌与害虫的益害比,实现害虫的可持续控制。     

Seasonality of insect succession on exposed rabbit carrion in Guangzhou, China

Abstract  Succession patterns for insect fauna, spanning four seasons, on rabbit carcasses were studied in Guangzhou China from 2006 to 2008. A total of 49 taxa belonging to three orders and 15 families were collected and identified. Four decomposition stages were recognized: fresh, bloated, decay and dry stage. Taxa diversity was higher in bloated and decay stages than fresh and dry stages. Internal and ambient temperatures were measured. Maximum internal temperature arrived earlier in warmer seasons. The sequence of insect succession in this study follows the same general patterns: the Diptera peaked initially, and the Coleoptera peaked later. Chrysomya megacephala was the dominant species in four seasons. Its time point of different development stages on carrion could be the most important indicators for PMI (postmortem interval) estimation in Guangzhou. Yearly and seasonal differences in activities of insects were compared. Alpha diversity indices were calculated. There were no significant differences in Shannon-Wiener index, evenness ( J ) and dominance ( C ) between seasons and years. From the Jaccard similarity index, the highest similarity was between winter and spring, while the lowest was between summer and winter. Some species occurring exclusively in one season may be important to characterize different seasons. A list of the insect taxa associated with above-ground rabbit carrion during the four seasons was compiled, which can be used for estimating time since death in similar bio-climate areas.     

利用红树植物监测海岸油污染方法初探

一、前言在海洋污染物中,石油污染是最普遍和最严重的一种。这种污染主要来自海上油船运输泄漏、海洋油田开发、油层自然渗出造成的远洋石油污染。近年来,随着沿海各地拆船工业的迅速发展,由于忽视环保工作或环保措施跟不上生产发展,拆船作业中大量含油压仓水排入海中,以及船只轮机部位大量存油,油垢溢     

Determinants of predation on phytophagous insects: the importance of diet breadth

To evaluate the role of predation in the evolution of diet specialization and to determine the effectiveness of various larval defenses, we offered lepidopteran larvae to colonies of the tropical ant Paraponera clavata. We recorded behavioral and physical characteristics of prey items and used log-linear models to analyze their importance as deterrents to predation by P. clavata. The most important determinant of probability of prey rejection by P. clavata was a prey's diet breadth; specialists were rejected by the ants significantly more than generalists. Other less important, but significant, predictors of prey rejection included ontogeny, morphology and chemistry. Late instar caterpillars were rejected more frequently than early instars, hairy caterpillars were rejected more frequently than caterpillars with other morphologies, and one caterpillar species with an unpalatable extract was rejected more frequently than two species with palatable extracts.