农药对蜜蜂的影响及毒理学机制研究进展

农药在现代农业生产中发挥着积极作用,但是农药使用不当则会对重要授粉昆虫如蜜蜂等造成负面影响。本文主要围绕农药对蜜蜂的急性毒性、亚致死剂量农药对蜜蜂生长发育和行为的影响,农药对蜜蜂的联合作用,以及新烟碱类杀虫剂与蜜蜂烟碱型乙酰胆碱受体的相互作用、农药对蜜蜂毒性差异的机理、农药对蜜蜂解毒代谢相关酶活性及其他生理生化指标的影响、植物化学物质在调控蜜蜂对农药耐受性中的作用等方面的研究进展进行了综述,以期为农药的合理使用及提高其对蜜蜂的安全性提供参考。     

转基因昆虫在害虫防治上的应用前景

对转基因昆虫的发展历史,转基因昆虫的技术要点,特别是载体和标记基因进行了系统阐述,同时对转基因昆虫的应用方向和生物安全性及其管理做了简要介绍。     

新烟碱类杀虫剂对蜜蜂亚致死效应的研究进展

蜜蜂是一种经济型昆虫,其授粉作用在农业生产、濒临植物保护等方面具有重要意义。新烟碱类杀虫剂的广谱性、高效性、对哺乳动作的低毒性使得这类药剂备受人们关注,被广泛使用在农业生产生活中。近年来,新烟碱类杀虫剂对蜜蜂的潜在威胁也成为研究的热点,特别是对蜜蜂亚致死效应的研究。本文简要介绍了新烟碱类杀虫剂的应用概况及其作用机理,重点阐述了亚致死剂量的新烟碱类杀虫剂对蜜蜂生长发育及行为等的影响,并提出了几个有待进一步研究解决的问题,以期为我国新烟碱类杀虫剂对蜜蜂的安全性评价工作提供参考信息。     

有关转基因植物农药的安全问题

转基因植物农药是指利用分子生物学和基因工程技术将外派目标基因插入受体植物的基因组，使其遗传组成改变；以达到防浪病、虫、草、鼠害目的而产生的植物农药产品。在美国这种农药被称为“pjantpesti－”，这与一般意义的生物农药是有区别的。为完善基因工程工作的安全管理，国家科委于1993年颁发了（基因工程安全管理办法》，农业部又针对我国农业生物基因工程领域的研究和开发，于1996年制订了（农业生物基因工程安全管理实施办法》。转基因植物农药的安全性问题还涉及到昆虫抗性的控制等一系列问题。历史上，常规育种技术在提高作物抗虫…     

基于RNA干扰原理抗病毒转基因作物的应用及安全性

基因沉默是广泛存在于各种生物中的一种古老现象,是生物抵抗外来入侵者的保护机制。RNA干扰（RNA interference,RNAi）则是近年来发现的一种重要基因沉默现象。此策略已在植物抗病毒育种等研究中应用,如对水稻、大麦、大豆、玉米、马铃薯、番茄、辣椒、木瓜、南瓜、李、烟草等的抗病毒研究。在转基因抗病毒展现出诱人的前景时,对转基因抗病毒植物释放的安全性问题的关注也越来越多。本文介绍了RNAi的作用机制,在转基因抗病毒育种中的应用,并探讨了以RNAi为基础的转基因抗病毒作物的食用安全性和环境安全性等问题。     

植物病毒在媒介昆虫体内的垂直传播研究进展

对于多数植物病毒而言,其在田间的自然扩散主要依赖昆虫等介体生物,而媒介昆虫的垂直传播是植物病毒长期存在并发生的重要原因。对媒介昆虫垂直传播病毒机制的研究不仅可以为未来开发高效低毒农药奠定基础,更可为植物病毒与昆虫的互作和病毒病的预测预报提供新的视野及角度。媒介昆虫在植物病毒传播过程中的具体作用在近几年被广泛研究。该文综述了近年来植物病毒在昆虫体内垂直传播的研究进展,包括昆虫传播植物病毒的方式、植物病毒在昆虫体内的垂直传播方式以及虫媒病毒垂直传播的可能机制等。在整个垂直传播的过程中,植物病毒的衣壳蛋白、磷蛋白和媒介昆虫唐氏综合症细胞黏附分子、硫酸乙酰肝素糖蛋白、热激蛋白以及卵黄原蛋白,甚至共生菌都有参与。最后,基于媒介昆虫和植物病毒的关系对未来植物病毒病的绿色防控和生物防控进行了展望。     

转基因植物重组DNA和表达蛋白的环境分子行为

转基因植物的安全性已经在全球范围内引起了普遍关注。本文从分子水平上就转基因植物的重组DNA在环境中的降解动态、转基因植物重组DNA在生物体内的传递、转基因植物杀虫蛋白在环境中的降解及在食物链间的传递等有关研究进展作一简要介绍。     

花卉害虫切叶蜂值得研究

切叶蜂(Megachile sp. ),属蜜蜂总科切叶蜂科,是豆科牧草及其他植物的传粉昆虫,多被列为益虫。但此蜂也为害花卉、行道树及部分果树,而且近年来发生日趋严重。根据初步调查切叶蜂为害7科17种植物,其     

美国生物农药的主要类别

美国登记注册的生物农药主要分为生物化学农药和微生物类农药,其中生物化学农药包括引诱剂、驱避剂、天然昆虫/植物生长调节剂及除草剂、信息素、其他生化农药等;微生物类农药包括细菌、真菌、病毒、酵母、原生动物、工程菌、转基因植物等。     

植物病毒转基因风险性分析

随着商品化的转基因植物品种的发放 ,与生态环境风险有关的一些问题已提上了议程。许多问题对所有的转基因植物都带有普遍性 ,而且涉及到潜在的生态环境影响。尽管对转基因插入片断进行了精心的设计 ,但转入植物后可能会导致植物的代谢变化。因此 ,在发放转基因植物之前 ,必须进行安全性测试 (Ｄｉｅｔｚ,1 993 )。对于所有转基因植物 ,特别引起关注的两点是 :远缘杂交导致基因的转移和潜在的表现型变化。转基因植物与其近缘种杂交可能会产生新的野生种群。如果这些新的野生种群表达转基因性状 ,可能会围绕转基因植物产生生态系统的演化。远…     

Introduced weeds pollinated by introduced bees: Cause or effect?

In the present review we attempt to synthesize evidence for a causative relationship between the presence of non-native bee pollinators and the successful establishment and spread of introduced weed species. Using data drawn from the literature and from our own survey conducted in New Zealand, we show that introduced bees favor foraging on introduced plant species, and that in some cases they depend totally on these plants as sources of nectar and pollen. It is also apparent that the flowers of many introduced plants are visited, exclusively or predominantly, by introduced bees. Accepting that visitation does not necessarily imply pollination, and not all plants require pollination to reproduce, we review relationships between seed set of exotic weeds and visitation by introduced pollinators. Although few studies have been carried out, we show that those reported so far all point to increased seed set when introduced plants are visited by non-native bee species. There is clear evidence for a positive link between the spread of weeds and the presence of introduced bees. Nevertheless, ecologists have neglected this aspect of weed population biology and remarkably few studies have been conducted on the importance of pollinator availability in the management of weed species. We suggest several avenues along which future research can be conducted and highlight how the management of present and future weed species may be influenced by this research.     

Herbicide-resistant genetically modified crop: assessment and management of gene flow

Genetically modified (GM) crops have become a reality in our cropping system. The experiences with GM oilseed rape have shown that gene flow from a GM crop causes genetic contamination of non‐GM crops and natural flora. This review summarizes technically available methods for gene flow assessment and proposes possible management methods. Methods for direct monitoring of gene flow include direct bioassay of plants and detection of phenotypic and molecular genetic markers contained in GM crops. A recent green fluorescent protein (GFP) marker technique can be powerful in monitoring gene flow as GFP inserted into a plant can be observed macroscopically under UV light. Appropriate analysis of data from direct assessment may give more useful information to mitigate gene flow. Observation with direct method provides real‐time data and mathematical‐statistical approaches may enable the long‐term consequence to be predictable. Although an estimated gene flow is less than an acceptable level, gene flow must be maintained as low as possible with a systematic management. The management should be conducted stepwise; selection of gene flow‐proof GM crops in the stage of development, risk assessment and regulation in the registration stage, cultural management, produce handling/transportation and a long‐term monitoring in cropping stage. Promising methods for developing gene flow‐proof GM crops include conferring cleistogamy and chloroplast transformation to mitigate pollen flow, and breeding non‐ or minimum shedding cultivars to mitigate seed dispersal. We strongly suggest that very high expression of a transgene or stacking multiple transgenes in the chloroplast could disturb the function of normal physiology, hence decreased performance of the GM crop. Before the approval of GM crops, proposed GM crops must go through the risk assessment. If the estimated risk of a GM crop exceeds an acceptable level, approval must be suspended. Once a GM crop is allowed for commercial release, additional efforts must follow, such as a continued long‐term monitoring of the impact of GM crop cultivation, crop and herbicide rotations, GM crop‐suited cultural practices, ‘right‐time’ harvest, and all necessary gene flow‐preventive practices. Such a systematic management incorporating various methods for the stages of GM crop utilization will minimize the risk of gene flow.     

Risk assessment to honey bees: a scheme developed in France for non-sprayed systemic compounds

BACKGROUND: Directive 91/414/EEC envisages that the systemic properties of active substances, if any, are taken into account in evaluating the risk posed to the environment by plant protection products. Among others, honey bees may be exposed to substances via this route, which may pose problems when substances with high toxicity are ingested through pollen or nectar. The guidance documents in support of the risk assessment to bees within the framework of Directive 91/414/EEC do not provide detailed technical guidance on how to proceed in a risk assessment for substances with systemic properties. RESULTS: A stepwise approach aiming specifically to assess the risk posed by non-sprayed systemic substances to bees is therefore proposed. This approach first identifies substances with systemic properties, which should be quantified in plant material as pollen and nectar. Exposure estimates calculated for different categories of bees (e.g. foraging bees), based on expected concentrations of the product in pollen or nectar, may be compared with several toxicity endpoints for acute or chronic effects on adults and/or larvae with a toxicity/exposure ratio, which is a measurement of potential risks. CONCLUSION: Such a ratio is proposed to be used as a trigger for any further refined assessment that would focus on the measurement of effects at the colony level.     

植食性昆虫唾液调控昆虫-植物互作的研究进展

在与寄主植物长期共同进化的过程中,为了更好地适应和利用寄主,植食性昆虫进化出了多种取食方式。同时,为了应对植食性昆虫的取食,植物进化出了多种防御策略,包括直接防御和间接防御。在整个昆虫-植物互作过程中,昆虫唾液起着重要作用。一方面,昆虫唾液中一些组分可以被植物识别并诱导植物防御反应;另一方面,昆虫通过分泌唾液到植物中调控寄主防御反应。该文从昆虫-植物互作的角度出发介绍植食性昆虫唾液的成分与功能,着重对昆虫唾液激发子和效应子的研究进展进行了综述,并对未来唾液的研究及其在害虫防治中的应用进行展望。     

二氧化硫对植物的影响及植物的自我修复

近年来SO2污染比较严重，它对植物有着多方面的影响。目前，SO2单一污染物对植物生理生化的直接影响已比较清楚，但SO2对植物的间接影响以及SO2与其他污染物对植物的复合影响，特别中在分了水平上研究SO2的影响等内容尚不清楚。植物一方面要受到SO2污染的影响，另一方面又对SO2的影响具有一定程度的修复能力。植物细胞保护酶通过清除活性氧在植物的自我修复中起着重要的作用。     

Gentechnisch veränderte Bäume für eine nachhaltige,umweltverträgliche und ressourcenschonende Produktion von Holz für die Energiegewinnung

Genetically modified trees (GM trees) are long-living plants. In regard to their special ecological and economic importance deployment of genetically modified trees is controversial because of the possible risks they are involved.Commercial use of GM trees for example as a plantation culture is supported by proponents, if they were previously subjected to a comprehensive risk analysis and safety assessment. In contrast, many critics exclude a commercial use of GM trees completely. They demand to stop the research.In this paper, the possibilities of a sustainable, environmentally sound and resource-efficient use of GM trees are discussed. Arguments are given in favor of GM trees in respect to both, as a source of renewable raw material to cover an increasing demand for energy and chemical raw materials.Besides, arguments are given in favor of GM trees to mitigate effects of climate change in comparison to agronomical energy crops such as maize, sugar beet and cereals.Finally, an overview of an international project on risk assessment of GM trees (recently approved by the European Union) is given. The paper concludes with a presentation of requested and approved field trials of GM trees in the last five years in Europe.     

Sugar concentration in nectar: a quantitative metric of crop attractiveness for refined pollinator risk assessments

Those involved with pollinator risk assessment know that agricultural crops vary in attractiveness to bees. Intuitively, this means that exposure to agricultural pesticides is likely greatest for attractive plants and lowest for unattractive plants. While crop attractiveness in the risk assessment process has been qualitatively remarked on by some authorities, absent is direction on how to refine the process with quantitative metrics of attractiveness. At a high level, attractiveness of crops to bees appears to depend on several key variables, including but not limited to: floral, olfactory, visual and tactile cues; seasonal availability; physical and behavioral characteristics of the bee; plant and nectar rewards. Notwithstanding the complexities and interactions among these variables, sugar content in nectar stands out as a suitable quantitative metric by which to refine pollinator risk assessments for attractiveness. Provided herein is a proposed way to use sugar nectar concentration to adjust the exposure parameter (with what is called a crop attractiveness factor) in the calculation of risk quotients in order to derive crop‐specific tier I assessments. This Perspective is meant to invite discussion on incorporating such changes in the risk assessment process. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Risk assessment for honey bees and pesticides—recent developments and ‘new issues’

In 2008, major areas of discussion at the ICPBR Bee Protection Group meeting were the development of a honey bee risk assessment scheme for systemic pesticides and revision of the test guidelines for semi‐field and field studies. The risk assessment scheme for systemic pesticides is based on analysis of conditions for exposure of bees to residues. These are based on a stepwise approach, starting with simple calculations based on existing data in dossiers and progressing to higher‐tier semi‐field and field studies (the guidelines for these have been modified in line with this). The proposed scheme has been tested with data packages of high‐ and low‐risk PPPs. A future area of interest for the group may be the risks posed by guttation fluid containing systemic pesticides. A recent paper on ‘Translocation of neonicotinoid insecticides from coated seeds to seedling guttation drops: a novel way of intoxication for bees’ has focused significant interest on the possible risks posed by the presence of residues of systemic pesticides in guttation fluid to water‐collecting honey bees. The occurrence of guttation and the presence of pesticide residues in the fluid are discussed, together with remaining questions that will need to be addressed in answering whether such a route of exposure may pose a risk to honey bees. © Crown copyright 2010. Reproduced with permission of Her Majesty's Stationery Office. Published by JohnWiley & Sons, Ltd.     

Dietary traces of neonicotinoid pesticides as a cause of population declines in honey bees: an evaluation by Hill's epidemiological criteria

BACKGROUND: Honey bees are important pollinators of both crops and wild plants. Pesticide regimes that threaten their sustainability should therefore be assessed. As an example, evidence that the agricultural use of neonicotinoid pesticides is a cause of the recently observed declines in honey bees is examined. The aim is to define exacting demographic conditions for a detrimental factor to precipitate a population decline, and Hill's epidemiological ‘causality criteria’ are employed as a structured process for making an expert judgement about the proposition that trace dietary neonicotinoids in nectar and pollen cause population declines in honey bees. RESULTS: In spite of the absence of decisive experimental results, the analysis shows that, while the proposition is a substantially justified conjecture in the context of current knowledge, it is also substantially contraindicated by a wide variety of circumstantial epidemiological evidence. CONCLUSION: It is concluded that dietary neonicotinoids cannot be implicated in honey bee declines, but this position is provisional because important gaps remain in current knowledge. Avenues for further investigations to resolve this longstanding uncertainty are therefore identified. Copyright © 2012 Society of Chemical Industry     

Toxicity of diafenthiuron to honey bees in laboratory,semi‐field and field conditions

BACKGROUND: Cardamom, an important spice crop often attacked by many insect pests, is controlled mainly using synthetic insecticides. As honey bees play a vital role in pollination in cardamom, the impact of insecticides on honey bees needs to be explored to assess its safety. RESULTS: Risk assessment based on contact toxicity revealed diafenthiuron to be a non‐selective insecticide to bees with a low selectivity ratio (the ratio between the LD₅₀ for beneficial and pest species). A dose of diafenthiuron that killed 90% of cardamom borer, Conogethes punctiferalis Guenee, was found to kill 100% of Indian bees. Based on the hazard ratio (the ratio between the field‐recommended dose and the LD₅₀ for the beneficial), diafenthiuron was found to be slightly to moderately toxic to bees. Diafenthiuron, even at low concentrations of LC₁ (the concentration that killed 1% of bees), was found to affect the foraging and homing behaviour of Indian bees. Of bees fed with 30 µg mL^?1 of diafenthiuron, 40% were found missing on the third day after exposure. However, diafenthiuron did not affect bee visits to the cardamom fields. CONCLUSION: Diafenthiuron is more highly toxic to Apis cerana indica F. than to C. punctiferalis by contact, using selectivity ratio and probit substitution methods of risk assessment, but the hazard ratio revealed diafenthiuron to be a slightly to moderately toxic chemical. Diafenthiuron was found to affect the foraging and homing behaviour of bees at sublethal concentrations. Thus, sublethal effects are more relevant in risk assessment than lethal and acute effects. Copyright © 2010 Society of Chemical Industry