水稻田几种害虫调查方法的准确性比较

田间调查是一种评估害虫及天敌种群数量的科学方法。田间调查的方法很多,为比较不同调查方法之间的准确性差异,笔者曾用目测法、水盆法、粘板法、吸虫法对水稻害虫及天敌作过调查,现将结果整理如下:材料与方法调查田面积约0.5亩,品种为 IR—72,水稻正处于幼穗分化始期。调查时,将调查田分成4个小区,每个小区用下列4种方法之一调查20丛稻上的害虫及天敌数量。这4种调查方法是:1.目测法:即用眼睛直接计数水稻上的害虫及天敌数量。为使害虫及天敌不因人为     

宁夏麦蚜天敌多样性及种间关系

麦蚜是宁夏小麦的主要害虫,为了实现自然天敌对麦蚜的有效控制,采用网捕法和陷阱法等采集手段,通过3年田间调查,共鉴定麦蚜天敌97种,包括寄生性天敌16种和捕食性天敌81种。将麦蚜天敌划分为单食性天敌、寡食性天敌、多食性天敌及杂食性天敌共4类功能团进行分析,结果表明,不同天敌功能团对麦蚜种群的影响存在显著的交互作用;寄生性天敌中蚜茧蜂属的燕麦蚜茧蜂与烟蚜茧蜂是优势种;捕食性天敌种类较为复杂,不同地区麦蚜天敌组成存在显著性差异,复杂的农业景观能够维持更高的天敌多样性。表明在农业生态系统中建立和恢复非作物生境能够明显提高天敌种群数量,进而提高其生物防治作用。     

天敌昆虫控害作用机制和评价方法研究进展

天敌昆虫是自然界生态系统中防控害虫的重要因子。利用天敌昆虫防治害虫是安全、有效的害虫防控策略。在农田生态系统中,天敌昆虫对害虫起着重要的调控作用,因此,充分利用天敌昆虫的控害作用就显得非常重要。本文阐述了天敌昆虫的控害机制,包括天敌昆虫控害作用的化学通讯机制、寄生蜂对寄主免疫的调控和天敌昆虫的间接控害作用三方面,还介绍了定量评价天敌昆虫控害作用的三种方法:罩笼接虫法、稳定同位素法和分子标记技术。     

评估农药对水稻天敌风险试验研究

长期以来．通常衡量农药的标准是高效、低毒、低残留．而农药对天敌的影响至今未被列入衡量标准。南京农业大学植保学院农药学系承担并完成了农业部“高毒农药替代试验示范项目”中“替代药剂对水稻天敌风险评估”试验，将药剂对天敌的安全性评估作为选择药剂的依据之一。根据药剂对天敌室内毒力和田间药剂试验两方面的研究结果，来综合评估替代药剂对稻田主要天敌的风险是该项目的创新。     

小贯小绿叶蝉与其主要天敌空间关系研究方法的比较

天敌与目标害虫空间关系密切与否,直接关系到天敌对目标害虫的控制利用。为了选择较为理想的天敌与害虫之间空间关系的研究方法,本文用地统计学法、模糊相似优先比法,扩散系数法、空间生态位重叠指数法和聚块样方方差分析法研究‘黄山大叶种’茶园和‘农抗早’茶园天敌与小贯小绿叶蝉Empoasca onukii 空间关系密切程度,以地统计学法的结果为标准,以其前3位天敌粽管巢蛛Clubiona japonicola、斜纹猫蛛Oxyopes sertatus和鳞纹肖蛸Tetragnatha squamata的位次之和为据,根据位次差别评论5种研究方法研究结果的一致性。聚块样方方差分析方法研究结果与地统计学方法的结果差别较小,其次是扩散系数法和模糊相似优先比法,空间生态位重叠指数法研究结果与地统计学方法的结果差别较大。按照天敌与小贯小绿叶蝉空间关系密切程度位次分析,粽管巢蛛、斜纹猫蛛和鳞纹肖蛸是与小贯小绿叶蝉空间关系密切的前3种天敌。本文是对多种研究方法研究结果一致性进行比较的一种尝试,为分析天敌与害虫空间关系选择研究方法提供参考。     

有机稻田主要天敌类群及其群落多样性演替

本文应用群落多样性指数与田间调查法，评价了有机耕作稻田主要天敌类群的结构、变化及对稻飞虱自然种群的控制。结果表明，实施有机耕作一年半后，稻田蜘蛛类、捕食性天敌、寄生性天敌的物种多样性指数、丰富度指数、均匀度指数均有不同程度的提高；捕食因子、寄生因子对稻飞虱自然种群的作用显著强于常规耕作稻田。因此，有机耕作有利于自然天敌的恢复、保护，有利于稻田环境的改善。     

“天敌释放+”设施豇豆病虫害绿色防控技术模式

<正>“天敌释放+”是以温室大棚内释放天敌昆虫为核心,配合健身栽培、生态调控、理化诱控和生物农药等措施的全程绿色防控技术模式。2023年山东省在聊城市莘县妹冢镇大棚春提前茬豇豆开展病虫害绿色防控示范,以蓟马、斑潜蝇、叶螨、蚜虫、根腐病、锈病、灰霉病等病虫害为靶标,试验示范小花蝽、丽蚜小蜂、捕食螨等天敌释放的效果,集成天敌释放配套技术,评估技术模式的效果、效益。     

油茶园主要害虫茶袋蛾及其天敌间相互关系

2003年6月至2004年5月在对油茶园害虫茶袋蛾及其天敌种群数量系统调查基础上,运用生态位理论和灰色关联度及模糊贴近度方法,系统研究了茶袋蛾与其天敌间相互关系。结果表明:与茶袋蛾空间生态位重叠值>0.8758的天敌有跳蛛、圆蛛和蟹蛛;时间生态位重叠值>0.4748的天敌有蟹蛛、圆蛛和肖蛸。天敌与茶袋蛾灰色关联度较高的种类依次为圆蛛、姬蜂、小蜂、寄蝇和微蛛;与理想天敌关联度较高的天敌种类为微蛛、肖蛸、跳蛛、姬蜂和小蜂;天敌同茶袋蛾和理想优势种关联度总积分较高的依次为微蛛=姬蜂>圆蛛=肖蛸=小蜂。茶袋蛾与其天敌模糊贴近度最大的是圆蛛,其次为肖蛸。这些结果表明圆蛛对茶袋蛾追随效应显著,为优势种天敌,其次为肖蛸。     

黄秋葵田主要害虫、天敌种群动态及时间生态位分析

为了解黄秋葵田害虫和天敌的种类及种群动态变化情况,分析主要害虫和天敌间的生态调控机制,为黄秋葵田害虫的生物防控提供科学依据。通过目测法和5点取样法调查记录黄秋葵田害虫、天敌种类和数量,并对害虫和天敌间的生态位进行分析。结果表明,黄秋葵田内共发现6目13科21种昆虫,害虫优势种分别为棉蚜和棉大卷叶螟,两者在田间均呈聚集分布。天敌优势种分别为龟纹瓢虫、异色瓢虫、三突花蛛、草间小黑蛛、卷叶螟绒茧蜂、卷叶螟姬小蜂。其中蚜虫生态位宽度值最小,田间发生时间比较集中,主要在6月。棉大卷叶螟生态位宽度值最大,田间发生时间比较长,主要在7—9月。蚜虫与瓢虫的时间生态位重叠值为0.8593,瓢虫对蚜虫有明显的跟随效应,是蚜虫的优势性天敌。棉大卷叶螟与蜘蛛、卷叶螟绒茧蜂、卷叶螟姬小蜂的时间生态位重叠值分别为0.7220、0.7175、0.6797,这三类天敌对棉大卷叶螟有明显的跟随效应,对其种群具有协同控制效果,是控制棉大卷叶螟的三种优势天敌。以上结果表明,天敌对害虫在时间生态位上有一定的同步性,在田间管理时应加强对这些天敌的保护和利用,以增强天敌的自然控害功能。     

广西忻城县山银花病虫害及其天敌昆虫种类调查

为明确广西忻城县山银花病虫害及其天敌昆虫种类,为当地山银花病虫害防治和天敌的保护利用提供参考,2008年-2010年系统调查了广西忻城县山银花病虫及主要病虫天敌发生情况,并进行了种类鉴定.结果表明,广西忻城县山银花害虫有35种,病害11种,天敌昆虫28种,其中主要害虫的捕食性天敌有24种,寄生性天敌2种,取食白粉菌的瓢虫有2种.此外,本文还综述了广西忻城县山银花主要病虫害‘三虫一病’的特征、发生规律及防治方法.     

Development of methods for the analysis of crops and soils for residues of benzoylprop-ethyl and its breakdown products

Methods are described for the analysis of residues of the herbicide benzoylpropethyl, ethyl (±)-2-[ N-(3,4-dichlorophenyl)benzamido]propionate, and its breakdown product, (±)-2-[ N-(3,4-dichlorophenyl)benzamido]propionic acid, in wheat and soil. In wheat the acid degradation product conjugates with plant sugars and the present paper includes methods for determination of these residues either separately or as a combined residue with unconjugated acid. Efficient extraction procedures have been developed together with partition and column chromatographic techniques for purification of extracts. The full analytical procedures are described and the final determinations are by g.1.c. with electron capture detection with blank values for field samples in the range 0.01–0.05 mg/kg. Good recoveries were obtained. Radiochemical techniques have been used to verify the extraction and subsequent procedures in the methods.     

Efficacy and rates of diquat for reducing invasive knotweeds and potential for sequential use with imazapyr

Invasive knotweeds (Reynoutria spp.) pose an ongoing challenge for weed management programs worldwide, requiring years of persistent treatment. In this study, we tested efficacy of diquat applied as foliar spray early in the growing season for short-term suppression, and for potential to boost long-term control when applied sequentially with a mid-season treatment of imazapyr. We evaluated responses of knotweeds (R. japonica, R. × bohemica, and R. sachelinensis) treated with one of three diquat concentrations (0.25%, 0.50%, or 1.0%, v/v), using multiple metrics to capture changes in aboveground plant density and abundance. Canopy cover and biomass were significantly reduced by all diquat concentrations and resembled pre-treatment conditions at 8WAT, reflecting the shift toward reduced stem heights in treated compared with untreated plots. Stem counts at 8WAT, however, did not differ in response to diquat treatments. Sequentially applied early-season diquat and mid-season imazapyr treatments reduced canopy cover (66%–82%), biomass (65%–91%), and stem density (57%–79%) when evaluated 1 year after treatment; reductions were greatest in plots treated with medium and high diquat concentrations, suggesting that diquat treatments may have an additive effect. Overall, our study establishes rates of diquat to reduce biomass of invasive knotweed, and supports additional testing to assess improvement in long-term control when used sequentially with a systemic herbicide.     

新版欧盟原药和植物保护产品分析方法建立和报告指南文件概述

本文概述了欧盟最新发布的原药和植物保护产品分析方法建立和报告指南文件SANC0/3030/99第五版的基本内容.包括历史版本介绍、分析方法描述和报告的要求、用于产品登记的分析方法范围和适用性、分析方法确认过程中对各参数的要求、分析物定性确证要求以及跟我国相关文件的比较.作者认为本文的内容有助于国内相关从业人员更好地阅读和理解该指南文件,为他们在实验工作中提供更好的理论指导,也为我国今后更新《农药产品质量分析方法确认指南》提供重要参考.     

Analysis of soils for diclofop-methyl and diclofop

A method is described for the analysis of soils for residues of the herbicide diclofop-methyl, methyl (RS)-2-[4-(2,4-dichlorophenoxy)phenoxy]propionate, and its breakdown product diclofop, (RS)-2-[4-(2,4-dichlorophenoxy)phenoxy]propionic acid. Diclofop-methyl undergoes hydrolysis in the soil to diclofop, which also has herbicidal activity. A procedure, using a 1% phosphoric acid solution for extraction purposes, has been developed and gives good recoveries of both diclofop-methyl and diclofop at the 0.5 and 0.05 mg kg^?1 levels. After methylation, gas-liquid chromatography with electron-capture detection is used to determine total residue concentrations.     

A new tool for entry and analysis of virulence data for plant pathogens

The methods of Habgood (1970) and Gilmour (1973) for the assignment of pathogen race names are discussed and the advantages of a reversed octal system, based on Gilmour's octal code, are emphasized. A new spreadsheet, 'HaGiS', exploits these two designation systems to provide user-friendly and fast access to some routine steps in the analysis of virulence data for plant pathogen populations. It produces graphs and tables for frequency distributions (of pathotypes, isolate complexities and cultivar susceptibilities); sorted lists (e.g. of the races ranked by predominance); indices (of sample diversity and of pathogenicity for each differential cultivar); and coloured proximity matrices. Use of HaGiS requires knowledge of only a few basic functions of MS Excel 97^®. All graphs, tables, indices and matrices are generated automatically and displayed by switching to the corresponding worksheet. In addition to data analysis, the spreadsheet is convenient for the entry of experimental data, allowing for all commonly used assessment scales.     

The need for effective marking and tracking techniques for monitoring the movements of insect predators and parasitoids

Predators and parasitoids move through the landscape at a wide range of rates and over a broad range of spatial scales. Understanding the dispersal characteristics of such 'beneficials' is of crucial importance for classical, augmentative, inundative and conservation biological control. It is a key practice, following the release of 'classical' (exotic) and augmentative (indigenous) biological control agents, to assess whether they have become successfully established, and also to what extent the agent has spread from the release points. It is important in conservation biological control to understand the role that natural enemy movements play in the improvement of pest control achieved through the provision of pollen, nectar, shelter and/or alternative prey/hosts. Other aspects of predator and parasitoid movement pertinent to biological control are the role refugia play in influencing, via natural enemy movements, control of pest population numbers. In these areas and others, some form of marking and/or tracking of insect predators and parasitoids is usually required so that movements can be studied. This special issue considers the usefulness and limitations of marking and tracking techniques, through up-to-date reviews written by an international team of researchers who are actively involved in the study of predator and parasitoid ecology.     

Evaluation of a predictive model for Mycosphaerella graminicola for economic and environmental benefits

A method was developed to evaluate crop disease predictive models for their economic and environmental benefits. Benefits were quantified as the value of a prediction measured by costs saved and fungicide dose saved. The value of prediction was defined as the net gain made by using predictions, measured as the difference between a scenario where predictions are available and used and a scenario without prediction. Comparable 'with' and 'without' scenarios were created with the use of risk levels. These risk levels were derived from a probability distribution fitted to observed disease severities. These distributions were used to calculate the probability that a certain disease induced economic loss was incurred. The method was exemplified by using it to evaluate a model developed for Mycosphaerella graminicola risk prediction. Based on the value of prediction, the tested model may have economic and environmental benefits to growers if used to guide treatment decisions on resistant cultivars. It is shown that the value of prediction measured by fungicide dose saved and costs saved is constant with the risk level. The model could also be used to evaluate similar crop disease predictive models.     

辽河流域跨省界断面生态补偿共建共享帕累托改进研究

辽河流域生态补偿研究对防治辽河流域环境破坏具有重要意义。文中通过消除福利经济学帕累托相关的外部性来实现流域生态补偿帕累托改进,进而建立了辽河流域跨省界断面的生态补偿共建共享帕累托改进模型,选择2003-2010年辽河流域生态服务功能系统上游地区环境保护投入及上、下游地区的GDP数据,测算得到辽河流域可以通过对下游征税并对上游补偿或者谈判方法实现帕累托改进整体最优的补偿量范围可在32.63亿元和86.11亿元之间选择,明确了补偿前后辽河上、下游地区的福利变化,为辽河流域生态补偿提供了一种新的思路。     

Development of a species-specific and sensitive detection assay for Phytophthora infestans and its application for monitoring of inoculum in tubers and soil

A specific and sensitive PCR assay for the detection of Phytophthora infestans , the cause of late blight of potato, in soil and plant tissues was developed. A P. infestans -specific primer pair (INF FW2 and INF REV) was designed by comparing the aligned sequences of rDNA internal transcribed spacer regions of most of the known Phytophthora species. PCR amplification of P. infestans DNA with primers INF FW2 and INF REV generated a 613 bp product, and species specificity was demonstrated against DNA from nine other Phytophthora species and seven potato-blemish pathogens. In a single-round PCR assay, 0·5 pg pure P. infestans DNA was detectable. Sensitivity was increased to 5 fg DNA in a nested PCR assay using Peronsporales-specific-primers in the first round. As few as two sporangia or four zoospores of P. infestans could be detected using the nested assay. Procedures are described for detection of P. infestans in leaves, stem and seed potato tubers before expression of symptoms. A soil assay in which 10 oospores per 0·5 g soil were detectable was developed and validated using samples of field soil. The PCR assay was used to examine the long-term survival of sexual (oospores) and asexual (sporangia and mycelium) inoculum of P. infestans in leaf material buried in a replicated experiment under natural field conditions. Oospores were consistently detected using the PCR assay up to 24 months (total length of the study) after burial in soil, whereas the sporangial inoculum was detected for only 12 months after burial. Sporangial inoculum was shown to be nonviable using a baiting assay, whereas leaf material containing oospores remained viable up to 24 months after burial.