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1.
The relevance of studies on aphid-plant relationships for plant virus epidemiology is highlighted. Many behavior-modulating chemicals (semiochemicals) play a major role in intraspecific (pheromones) or interspecific (allelochemics) interrelations and therefore offer opportunities to interfere with virus transmission. Present knowledge on the role of semiochemicals in different behavioral events is emphasized using examples (alarm and sex pheromones, allelochemics involved in host selection, antifeedants) and their potential for controlling virus transmission and spread is discussed.  相似文献   

2.
A general awareness of environmental concerns, an increasing chemophobic populace and the reregistration of pesticides, both in the United States and in the European Community, with the concomitant loss of many pest control chemicals through cancellation of their registrations has provided an impetus for the research, development and commercialization of alternative, environmentally benign and safer plant protection products. Amongst such alternatives are pheromones, a class of semiochemicals whose commercial development is being championed by a neophyte industry made up, for the most part, of undercapitalized entrepreneurial companies for whom the major hurdle to the introduction of products into the marketplace is the time and cost required to complete the regulatory process. That pheromones and other semiochemicals are different from chemical insecticides has been recognized by several national regulatory agencies and the Food and Agricultural Organization of the United Nations [FAO]. Although these regulatory authorities have made significant contributions towards reducing the data requirements and hence the cost of pheromone product registration, it is widely felt that more can, and should be done to further expedite and harmonize pheromone regulation. The adoption of a structure/activity approach to the evaluation of health and environmental risks for types of lepidopteran pheromones together with a 90-day evaluation time-frame. This approach would satisfy the regulatory authorities' risk assessment for food and environmental safety while substantially reducing the cost to the registrants and expediting the registration. It is proposed that this approach be tested first in an actual product application to the US Environmental Protection Agency [EPA], with subsequent applications to other regulatory authorities. A database which could be modified already exists within the EPA and as other databases are incorporated, and shared with other regulatory authorities, harmonization of the regulation of pheromones may be possible. The application of this structure/activity approach should be expanded to other types of semiochemicals as the database is enlarged.  相似文献   

3.
蓟马信息素研究及应用进展   总被引:1,自引:1,他引:0  
蓟马是农作物和园艺作物上常见的重要害虫,其通过直接取食和间接传播病毒给作物造成了巨大的经济损失。应用蓟马信息素是蓟马害虫绿色防控的重要措施。本文综述了蓟马产生的信息化学物质的研究进展,概述了已报道的蓟马肛门分泌物的化学组分及其功能,介绍了已鉴定的蓟马报警信息素、聚集信息素、接触信息素和抑性欲信息素的主要成分、分泌部位、作用功能和合成方法,讨论了信息素在蓟马害虫防控中的应用潜能,并展望了目前蓟马信息素研究中存在的问题和未来的发展方向,以期为蓟马害虫信息素的合理应用提供指导。  相似文献   

4.
信息素是昆虫信息交流和信号传递的“化学语言”,能调节和控制昆虫的行为和生理变化。从本质上来讲,昆虫信息素就是有机化合物,不同昆虫的信息素在结构和成分配比等方面存在差异。昆虫信息素种类众多,根据作用机制可分为释放信息素和启动信息素;根据发挥的功能可分为性信息素、聚集信息素、报警信息素和标记信息素等。它们通过接收者的化学感受系统被识别和接收,过程十分复杂。目前,昆虫信息素在害虫防治、生物监控和保护以及促进昆虫授粉等多个领域被广泛应用。为后续进一步研究和利用昆虫信息素,该文从昆虫信息素结构差异和演化过程、分类和功能、传播和感知方式以及在生产实践中的应用等方面进行总结和综述,并对昆虫信息素的研究进行展望。  相似文献   

5.
寄生蜂寄主选择的化学信息调控   总被引:1,自引:0,他引:1  
在植物—植食性昆虫—寄生蜂三级营养关系链中,寄生蜂的行为常常受到其他两营养级的作用。对于寄生蜂而言,成功定位寄主是其发展种群的重要环节,在这个过程中,寄主昆虫的信息化合物和植物的信息化合物或两者的复合信息物质是寄生蜂搜寻寄主的重要线索,发掘这类信息物质并将其应用于害虫的生物防治体系,是当今害虫综合治理的一个重要举措。本文较全面地综述了化学信息物质在植物—植食性昆虫—寄生蜂三级营养关系中的信息调控及在寄生蜂保护利用中的作用,并对该领域今后的研究方向阐述了观点。  相似文献   

6.
性信息素是昆虫两性通讯的化学信号, 在物种繁衍中担当着重要的角色。以性信息素为基础的害虫诱杀和交配干扰等防治手段具有灵敏度高、选择性强、对天敌安全、不污染环境等优点, 在害虫综合治理和绿色防控体系应用中深受青睐。棉铃虫 Helicoverpa armigera 是一种世界性农业害虫, 具有适应能力强和寄主广泛的特点, 条件适宜时常大面积暴发成灾。以棉铃虫为代表的醛类性信息素的生物合成和调控过程, 是目前研究较早也较为透彻的一类性信息素。本研究概述了棉铃虫性信息素的组分和功能, 生物合成时的信号转导途径和调控机制, 以及性信息素前体的生成和特异性组分的碳链修饰过程, 并总结了当前研究的不足, 旨在为今后的基础研究和生产应用提供指导。  相似文献   

7.
昆虫类信息素研究进展及应用前景   总被引:2,自引:1,他引:1  
昆虫信息素具有微量、高效、无毒、不伤害天敌、不污染环境等优点,在害虫综合治理中发挥着重要作用。然而,天然信息素的高挥发性和在空气快速氧化以及合成成本高等问题限制了其在害虫综合治理中的实际应用。与天然信息素相比,昆虫类信息素具有更好的物理、化学和毒理性等优点,可以弥补天然信息素的不足,现已成为国内外的研究焦点。本研究对昆虫类信息素的概念与类型、研发与合成、特性及应用前景等方面进行归纳总结,阐述了利用昆虫类信息素在害虫综合治理上的研究状况,并展望了其应用前景。  相似文献   

8.
BACKGROUND: Mosquitoes are the most important vectors of human pathogens. Wide‐scale use of pesticides has led to the development of resistance to most common insecticide groups. The need to develop novel products that have a low impact on human health and the environment is well established. The toxicity of selected semiochemicals with molecular structures indicative of insecticidal activity was determined against adult Aedes aegypti (L.) and Anopheles quadrimaculatus (Say). The two most active insecticides against Ae. aegypti were also evaluated against Ae. albopictus (Skuse). RESULTS: Fifteen semiochemicals classified as terpenoid alcohols, ketones or carboxylic esters showed toxicity to both mosquito species. Geranyl acetone (LC50 = 38.51 µg cm?2) followed by citronellol (LC50 = 48.55 µg cm?2) were the most toxic compounds to Ae. aegypti, while geraniol and lavonax, with LC50 values of 31.88 and 43.40 µg cm?2, showed the highest toxicity to An. quadrimaculatus. Both geranyl acetone and citronellol were highly toxic to Ae. albopioctus. No semiochemical showed fumigation activity against either species. All semiochemicals persisted for less than 24 h when tested on filter paper. CONCLUSION: Quantification of LC50 values of several semiochemicals against Ae. Aegypti, An. quadrimaculatus and Ae. albopioctus showed that semiochemicals not only modify insect behaviors but also hold potential as potent insecticides for mosquito control programs. Copyright © 2010 Society of Chemical Industry  相似文献   

9.
10.
Insects that feed on the blood of vertebrates are difficult to control, and many previous efforts have been unsuccessful. This is becoming an ever increasing issue, not only in developing countries, but also in developed countries, as exemplified by the recent spread of West Nile virus by mosquitoes across the USA and recent dengue outbreaks in Singapore and Australia. Investigating the ways in which biting insects interact with each other, their environment and their hosts is providing valuable knowledge that will lead to the development of improved control technologies. For instance, recent advances in chemical ecology research have led to the identification of new semiochemicals that show great potential as control agents against biting insects. Exciting new chemical ecology tools and control technologies for the future are discussed.  相似文献   

11.
中红侧沟茧蜂Microplitis mediator与核型多角体病毒(nucleopolyhedrovirus, NPV)是棉铃虫Helicoverpa armigera的两种重要生物防治因子。中红侧沟茧蜂传播NPV对于利用二者协同防治棉铃虫具有重要意义。本研究探讨了给中红侧沟茧蜂饲喂含病毒蜂蜜水、体表喷洒病毒液、中红侧沟茧蜂在染毒宿主体内产卵、从染毒宿主体内发育、蜂茧浸泡病毒5种带毒方式的传播病毒效率,以及饲喂带病毒蜂蜜水方式下的传播机制。结果表明,饲喂带病毒蜂蜜水和体表喷洒病毒时中红侧沟茧蜂传毒率较高,在连续传毒的3 d内传毒效率分别为15.1%、9.1%~9.3%、2.4%~4%,其他3种方式传毒效率较低。在田间防治时可以利用中红侧沟茧蜂的传毒作用采用病毒与寄生峰的协同防控策略。  相似文献   

12.
13.
ABSTRACT Only larval thrips that acquire Tomato spotted wilt virus (TSWV), or adults derived from such larvae, transmit the virus. Nonviruliferous adults can ingest virus particles while feeding on TSWV-infected plants, but such adult thrips have not been shown to transmit TSWV. Immunofluorescence microscopy was used to show that thrips 1, 5, 10, and 20 days after adult emergence (DAE) fed on TSWV-infected plants acquired TSWV with virus replication and accumulation occurring in both epithelial and muscle cells of Frankliniella fusca (tobacco thrips [TT]) and F. occidentalis (western flower thrips [WFT]), as indicated by immunodetection of the nonstructural (NSs) protein encoded by the small RNA and the nucleocapsid (N) protein, respectively. Adult WFT acquired TSWV more efficiently than TT. There was no significant effect of insect age on TSWV acquisition by TT. In contrast, acquisition by adult WFT at 1 and 5 DAE was higher than acquisition at 10 and 20 DAE. Subsequent transmission competence of adult cohorts was studied by vector transmission assays. All adult thrips tested that had an acquisition access period as an adult were unable to transmit the virus. These results indicate the susceptibility of adult TT and WFT to infection of midgut cells by TSWV and subsequent virus replication and confirm earlier studies that adult thrips that feed on virus-infected plants do not transmit the virus. The role of a tissue barrier in TSWV movement and infection from midgut muscle cells to the salivary glands is discussed.  相似文献   

14.
番茄褪绿病毒Tomato chlorosis virus(ToCV)是一种由烟粉虱Bemisia tabaci传播的正义单链RNA病毒,在田间常与番茄黄化曲叶病毒Tomato yellow leaf curl virus(TYLCV)复合侵染而造成番茄生产上重大的经济损失。为了明确ToCV与TYLCV的复合侵染对烟粉虱传播ToCV所造成的影响,本文采用RT-PCR以及qRT-PCR检测了复合侵染的番茄对烟粉虱获取和传播ToCV的影响。研究表明,烟粉虱取食复合侵染的番茄后对ToCV的传播效率显著提高,仅25头烟粉虱的传毒率即可达到100%,ToCV在烟粉虱以及番茄体内的累积量均显著提高。说明这种复合侵染促进了烟粉虱对ToCV的传播,在田间应当及时防控烟粉虱,警惕病毒与烟粉虱的蔓延。  相似文献   

15.
BACKGROUND: Vector‐borne diseases continue to present significant threats to human, animal and plant health. Mosquitoes, houseflies, sand flies and stable flies are well‐known vectors of several human and animal pathogens. The toxicity of selected semiochemicals with molecular structures indicative of insecticidal activity was determined against these insect species with the aim of developing novel insecticides toxic to multiple insect species. RESULTS: Three semiochemicals, namely beta‐damascone, cyclemone A and melafleur, showed remarkable toxicity to three mosquitoes, Aedes aegypti L., Ae. albopictus (Skuse) and Anopheles quadrimaculatus Say, the housefly, Musca domestica L., the stable fly, Stomoxys calcitrans L., and the sand fly, Lutzomyia shannoni (Dyar). The chemicals were equally toxic to several field‐collected permethrin‐tolerant housefly strains. When formulated as 500 mL L?1 emulsifiable concentrates, the chemicals demonstrated stability and toxicity on filter paper and camouflage military fabrics, with persistence up to 8 days under laboratory conditions. The chemicals were equally effective under field conditions when evaluated on unpainted plywood panels, although a higher dosage was required under field conditions to achieve similar efficacy. CONCLUSION: Laboratory quantification of LC50 values and field efficacy of three semiochemicals as formulated compounds on mosquitoes, houseflies, stable flies and sand flies showed that these semiochemicals could serve as potent insecticides for multiple insect species. Copyright © 2010 Society of Chemical Industry  相似文献   

16.
In spite of the obvious advantages of storage systems for pheromone use, few attempts have been made to investigate the practical effectiveness of pheromones in such systems. The sex pheromone complex of Ephestia cautella (Walker) is described, and the possible natural functions of the components are suggested. Trials with the synthetic pheromones show that mating frequency of the moth can be reduced by slow release of the materials in a warehouse. The prospects for the use of pheromones in pest management in stores are discussed.  相似文献   

17.
ABSTRACT Ceratothripoides claratris, the predominant thrips species on tomato in Thailand, was tested for vector competence and efficiency to transmit Capsicum chlorosis virus (CaCV) (isolate AIT) to tomato. The efficiency of adult-stage transmission was influenced by the larval stage at which virus was acquired. Adult C. claratris showed 69% transmission efficiency after acquiring the virus as freshly emerged (<1 h) first-instar larvae. However, when just molted (<1 h) second-instar larvae acquired the virus, the percentage of adult transmitters significantly decreased (48%). Transmission efficiency of up to 47% was detected with second-instar larvae of C. claratris which had acquired the virus as freshly emerged first-instar larvae. Transmission efficiency did not significantly differ between adult males and females, irrespective of the larval stage at which the virus was acquired. Highest transmission efficiency for CaCV was recorded in adult C. claratris derived from second-instar larvae collected from infected tomato plants in a greenhouse. Lowest transmission efficiency was observed in adults directly collected from infected tomato plants in the greenhouse. The spread of CaCV on tomato plants in greenhouses showed a close association with thrips infestations.  相似文献   

18.
BACKGROUND: The housefly, Musca domestica L., and stable fly, Stomoxys calcitrans (L.) are cosmopolitan pests of both farm and home environments. Houseflies have been shown to be resistant to a variety of insecticides, and new chemistries are slow to emerge on the market. Toxicities of selected semiochemicals with molecular structures indicative of insecticidal activity were determined against adults from an insecticide‐susceptible laboratory strain of houseflies. The three most active semiochemicals were also evaluated against recently colonized housefly and stable fly strains. RESULTS: Nineteen semiochemicals classified as aliphatic alcohols, terpenoids, ketones and carboxylic esters showed toxicity to houseflies and stable flies. Rosalva (LC50 = 25.98 µg cm?2) followed by geranyl acetone and citronellol (LC50 = 49.97 and 50.02 µg cm?2) were identified as the most toxic compounds to houseflies. Permethrin was up to 144‐fold more toxic than rosalva on the susceptible strain. However, it was only 35‐fold more toxic to the insecticide‐tolerant field strain. The compounds generated high toxicity to stable flies, with LC50 values ranging from 16.30 to 40.41 µg cm?2. CONCLUSION: Quantification of LC50 values of rosalva, citronellol and geranyl acetone against susceptible housefly and field‐collected housefly and stable fly strains showed that semiochemicals could serve as potent insecticides for fly control programs. Copyright © 2010 Society of Chemical Industry  相似文献   

19.
The RMV strain of Barley yellow dwarf virus (BYDV-RMV) is an unassigned member of the Luteoviridae that causes barley yellow dwarf in various cereal crops. The virus is most efficiently vectored by the aphid Rhopalosiphum maidis, but can also be vectored with varying efficiency by R. padi and Schizaphis graminum. Field collections of alate aphids migrating into the emerging winter wheat crop in the fall of 1994 in central New York identified a high proportion of R. padi transmitting BYDV-RMV. This prompted a comparison of the BYDV-RMV isolates and the R. padi populations found in the field with type virus and aphid species maintained in the laboratory. A majority of the field isolates of BYDV-RMV were similar to each other and to the type BYDV-RMV isolate in disease severity on oat and in transmission by the laboratory-maintained population of R. maidis and a field-collected population of R. maidis. However, several field populations of R. padi differed in their ability to transmit the various BYDV-RMV isolates. The transmission efficiency of the R. padi clones was increased if acquisition and inoculation feeding periods were allowed at higher temperatures. In addition, the transmission efficiency of BYDV-RMV was significantly influenced by the aphid that inoculated the virus source tissue. In general, BYDV-RMV transmission by R. padi was higher when R. padi was the aphid that inoculated the source tissue than when R. maidis was the inoculating aphid. The magnitude of the change varied among virus isolates and R. padi clones. These results indicate that, under certain environmental conditions, R. padi can play a significant role in the epidemiology of BYDV-RMV. This may be especially significant in regions where corn is a major source of virus and of aphids that can carry virus into a fall-planted wheat crop.  相似文献   

20.
The incidence of alfalfa mosaic virus (AMV) in lucerne seed and pods during maturation, when monitored by sap transmission to Phaseolus (infective virus) and ELISA (AMV antigen), showed that infective virus incidence decreased rapidly with maturation, whereas antigen incidence declined slowly and was always higher than infective virus. Infective virus and antigen incidence were higher in mature seed of cv. Maris Kabul than cv. Europe because virus inactivation/degradation were more rapid in cv. Europe. Seed infection with virus originating from pollen, ovules or both was found in pods and seeds 12–15 days after pollination between healthy or AMV-infected plants; this was before maturation-associated virus inactivation. Ovule transmission was more frequent than pollen transmission. AMV antigen was present in embryos and testas of mature seed; infective virus only in embryos. Non-infective but ELISA-positive antigen in testa extracts accounted for the higher incidence of 'seed-borne AMV' compared with embryo-associated seed transmission to seedlings. Tests with dry mature seed either underestimated (infectivity tests) or overestimated (ELISA) eventual seedling infection. Infectivity and ELISA tests gave identical incidence values for 17 to 29-day-old seedlings.  相似文献   

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