农田景观格局对害虫天敌生态控害功能的调控作用

如何提升农田景观的生态服务功能是当前景观生态学和害虫防治学的前沿研究热点.基于区域农田景观格局可显著调节植物-植食性昆虫-天敌之间相互关系的理论基础,本文系统概括总结了农田景观格局及其变化对农田重要天敌多样性与生态控害功能的影响.从不同天敌类群的角度,分析了农田景观格局对捕食性天敌、寄生性天敌、有益微生物及其生态控害功能的调控作用.同时,对优化农田景观作物布局、采取合理的植被生境管理策略进行了展望.本文可为应用植被生境管理提升农田景观中天敌的生态系统服务功能提供参考,进一步促进区域生态农业响应"化学农药减量施用"的战略目标提供理论支撑.     

生境管理——保护性生物防治的发展方向

生境管理是近年来保护性生物防治的重要研究方向,也是利用农业景观格局进行生物防治的重要策略。生境管理是指从农田景观的角度,在大时空尺度范围内进行多种作物与非作物生境的设计与布局,创造有利于天敌的环境条件,抑制害虫种群发生,达到减小环境污染、增强农业生态系统的控害保益功能,最终实现害虫种群控制的可持续性。景观尺度下的生境管理不仅强调单一农田生物控害作用,而是以多生境农业景观整体布局为指导,探索各种生境功能的整合利用,以发挥各种生境最大的生物控害潜能,为实现多目标生态服务价值管理提供重要的理论基础和现实依据。本文系统地总结了生境管理的研究内容与实现途径,论述了农业景观格局与过程对害虫种群控制的机理,并对作为保护性生物防治发展方向的生境管理研究趋势进行了展望。     

功能植物的作用原理、方式及研究展望

通过种植蜜源植物、储蓄植物、栖境植物和诱集植物等以增强目标保护作物害虫天敌昆虫的生物控害功能,已成为害虫生态调控的一项重要途径。为此,本文从种植这些植物带来的生态系统服务与功能的角度,提出功能植物的概念,认为功能植物应为天敌和传粉昆虫提供"衣(传粉服务)、食(食物服务)、住(庇护服务)、行(转移服务)"的功能,而不能为目标害虫提供"衣(沾花点)、食(桥梁田)、住(庇护所)、行(扩散地)"作用,在发挥生物控害功能的同时,还可能带来诸如传粉、土壤涵养等其他生态系统功能;由此进一步总结了功能植物的作用原理、主要特征、作用方式及其与其他相关名词的联系与区别,指出未来功能植物发展的趋势,为充分利用功能植物开展害虫生态调控提供理论参考。     

多尺度空间下害虫生态调控理论与应用

不同尺度空间下农田生态系统具有不同的生境斑块组成结构,尺度性也是生态系统的重要特征之一.近年来,北美和欧洲等地区用农田生境管理与区域性景观设计相结合的研究方法实施多尺度空间下害虫生态调控,实现复合生态系统服务.其核心思想是以大区域景观设计和农田作物布局与农事管理的有机结合,通过农业景观格局的空间配置,调节种植模式、管理技术、乃至改变农业景观格局的空间配置等以切断害虫种群的生活史,建立和恢复天敌种群库与转移通道,从而最大程度地提高农业生态系统自身的控害功能.近年来,北美和欧洲对多尺度空间下农业复合生态系统服务功能都做了大量工作,尤其是田间尺度与景观尺度相结合的研究方法更是当前生境管理研究的重要内容.本文总结了多尺度空间下生态系统环境条件与天敌种群间的作用机制及假说,包括田间尺度上主要通过轮作与间套作、覆盖作物、减免耕及发展有机农业等方式提高天敌种群,景观尺度上通过生境斑块的空间配置来改变植物资源布局,最终提高天敌的控害作用.以期为深入地解析景观格局及复杂性对生物多样性的影响,揭示农业景观变化对昆虫种间关系的作用机制,在实践上为利用农田景观格局控制害虫种群发生提供新的途径与方法.     

功能植物苣荬菜的特征及其应用潜能

苣荬菜Sonchus arvensis L.在我国广泛分布,具有耐干旱、耐盐碱、适应性强、管理简便、花期长的特点。我们于2018年9月最先在山东发现苣荬菜上涵养着大量的天敌昆虫和传粉昆虫。经过进一步调研,显示苣荬菜与周围作物(玉米、小麦)无共同害虫,其花期7-10月,与玉米生长同期,可为玉米田天敌昆虫提供持续的营养补充,维持天敌昆虫种群;同时也是一种优质的蜜粉源植物,符合功能植物的基本特征。本文综述了苣荬菜作为华北玉米田功能植物的特征,建议通过在玉米田边通过种植苣荬菜可作为玉米害虫生态控害的手段,以实现维持天敌生物控害、减少化学农药投入、增加收入、改善农田生态环境和美丽乡村等目标。     

中国农业昆虫生态调节服务价值估算

昆虫是生物多样性最丰富的物种类群,其在维持生态系统功能,维系并保持着自然界的生态平衡,满足人类需求中的具有重要作用。讨论了昆虫生态服务价值的定量估算方法,基于2007年统计数据,计算了我国农牧业生产中昆虫传粉功能、天敌昆虫控害功能和分解作用的服务价值。结果表明,昆虫在我国农业生产中传粉服务价值为6790.30×108元,占其当年农作物生产总经济价值的54.05%;天敌昆虫的控害服务价值为2621.00×108元,占其当年重要作物总经济价值的9.09%;分解昆虫(甲虫)对牧场牛羊排泄物的分解作用的价值远超过90.84×108元。由此估计出了我国2007年农业昆虫生态调节服务总价值超过9502.14×108元,相当于当年国内生产总值GDP的3.7%。显示昆虫所产生的生态调节服务价值,与我国森林或草地生态系统的直接和间接服务价值处于同一数量级,同样具有巨大的经济价值。为保护与利用昆虫生物多样性,发挥其生态服务功能奠定了基础。     

农业景观生物多样性与害虫生态控制

现代农业的一个重要特征就是人类对农田生态系统的干扰强度及频率不断增加,严重影响农业景观的结构及其生物多样性.农业景观结构的变化及其生物多样性的丧失,必然引起生态系统服务功能的弱化,不利于实施以保护自然天敌为主的害虫生态控制.农业的集约化经营导致自然生境破碎化,减少了农业景观的复杂性,使得作物和非作物变成一种相对离散化的生境类型和镶嵌的景观格局;破碎化的生境不仅会减少某些物种的丰度,还会影响物种之间的相互关系及生物群落的多样性和稳定性.非作物生境类型如林地、灌木篱墙、田块边缘区、休耕地和草地等,是一种比较稳定的异质化环境.非作物生境较少受到干扰,可以为寄生性和捕食性节肢动物提供适宜的越冬或避难场所以及替代猎物、花粉和花蜜等资源,因此,非作物生境有利于自然天敌的栖息和繁衍,也有利于它们迁入邻近的作物生境中对害虫起到调节和控制作用.景观的格局-过程-尺度影响农田生物群落物种丰富度、多度、多样性以及害虫与天敌之间的相互作用.从区域农业景观系统的角度出发,运用景观生态学的理论和方法来研究作物、害虫、天敌等组分在不同斑块之间的转移过程和变化规律,揭示害虫在较大尺度和具有异质性的空间范围内的灾变机理,可为利用农业景观生物多样性来保护农田自然天敌,实施害虫的区域性生态控制提供新的研究思路和手段.     

北方富含天敌的功能植物的发现与应用

蛇床Cnidium monnieri(L.)Cuss.是我国大部分地区均有分布的一种具有重要药用经济价值的植物。我们于2012年6月最先在北方发现蛇床上富含瓢虫、食蚜蝇等天敌昆虫,具备功能植物的基本特征。进一步研究发现,蛇床可使天敌昆虫提前迁入,在麦田害虫发生之前助增天敌瓢虫迁入麦田控害,且作为小麦、玉米之间的廊道以及它们收获后天敌的保育场所,从而周年实现对害虫的生态调控。蛇床同时具有种植管理轻简,适生性强,种子不扩散到农田内部成为杂草,且具观赏功能等可应用特点。因此,通过作物周边种植蛇床,作为害虫生态调控的一种新途径,可为农民实现增收、减少化学农药的使用、改善生态环境,具有重要的经济价值、生态价值和社会价值。     

区域性农田景观格局对麦蚜及其天敌种群的生态学效应

明确农田景观格局对害虫及其天敌种群的生态学效应,是开展区域性害虫生态调控的基础.以前的研究大多集中于小空间尺度下、单个景观因子对昆虫种群的作用,而从省级范围的大空间尺度、多个景观因子的分析很少.本文以山东省区域性小麦种植区为研究对象,基于遥感影像和土地覆盖分类数据以及田间调查的昆虫种群数据,分析了景观组成类型(component type)、构成比例(component proportions)和形状结构(shape structure)多因子对麦蚜及其天敌寄生蜂和瓢虫种群的综合作用.结果发现,农田景观组成类型中斑块类型(patch type)越多,越利于麦蚜和天敌瓢虫种群数量的增长;且斑块密度(patch density)越大,越利于麦蚜寄生蜂和天敌瓢虫数量的增加;景观形状结构中边界密度(edge density)越高,也越利于麦蚜寄生蜂和天敌瓢虫种群数量的增加.进一步定量评估了农田景观组成类型、构成比例和形状结构对麦蚜及其天敌种群影响的作用大小.结果表明,三类景观格局因子对麦蚜影响较小,权重为9.81%;而对麦蚜寄生蜂的影响权重为25.87%;对天敌瓢虫种群高达47.86%.本研究清楚地表明,通过优化农田景观中作物与非作物生境布局,可直接调节和增加天敌昆虫种类与数量,有效控制和减少小麦蚜虫的种群数量,从而提高区域性农田景观中天敌昆虫的生物控害服务功能.     

利用生物多样性控制作物害虫的理论与实践

生物多样性是人类可持续发展的重要基础,保护和利用生物多样性是国际社会普遍关注的问题。近年来,通过改善农田生物多样性和强化农田生态系统保益控害的服务功能,实现作物病虫害生态调控已成为国内外研究的热点。本文在总结分析国内外利用生物多样性控制害虫理论研究和实际应用的基础上,综述了该领域的研究进展、实践成果和发展前景。文中介绍了生物多样性的基本概念及其与害虫综合治理的关系,系统概述了利用农田生物多样性控制作物害虫的各种理论假说,包括天敌假说、资源集中假说、联合抗性假说、"推-拉"假说、中度复杂假说、景观缓冲假说等;从提高天敌多样性、作物多样性、非作物多样性和景观多样性等方面综合评述了利用农田生物多样性控制作物害虫的应用实践,重点介绍了我国的一些典型的实际应用案例,旨在充分展示中国昆虫学科技工作者在该领域做出的贡献;针对现代农业集约化经营导致农田生态系统结构简单、农田生物多样性不断下降等特点,对如何以农田景观为单元进一步做好利用生物多样性控制作物害虫的理论研究和应用实践进行了讨论和展望。     

农田非作物生境调控与害虫综合治理

就害虫综合治理的研究而言,农田生态系统可以区分出作物生境和邻近作物的非作物生境。昆虫从作物生境迁移到非作物生境,与作物生境缺乏食物或受人类栽培活动干扰而引起的自然迁移、转换寄主和寻求庇护场所有关。许多研究表明,与特定作物田块相联系的植被类型和结构可影响害虫及其天敌迁居的种类、数量和时间。因此,我们可以通过改变大田周围非作物生境的植被组成及特征来调控农业生态系统中害虫与天敌的相互关系,提高天敌对害虫的控制效能。由于景观的空间格局对节肢动物的生物学特性有直接或间接的影响,所以,以景观为单元要比以同类作物的田块为单元更加适于害虫综合治理的研究和实施。在现代农业景观区域内重新引入和相嵌一些非栽培植物或廊道,可为众多有益节肢动物的繁殖、取食和避害提供多种类型的非作物栖境。     

Habitat linkages in conservation biological control: Lessons from the land–water interface

Terrestrial landscapes, including those with embedded agroecosystems, are a mosaic of cover types varying in size. Creating or maintaining habitats that support natural enemy populations to combat agricultural pests is the primary method of conservation biological control. Non-crop habitats can be managed in an attempt to maximize the exchange of natural enemies with adjacent agroecosystems with the expectation that they will suppress damaging pest outbreaks. Despite this goal, current habitat management relying on natural enemy spillover into crops has been unreliably effective at reducing pest abundance or increasing crop yield. Furthermore, the expansion and intensification of agriculture and changes in global climate patterns threaten the foundations of conservation biological control in future agroecosystems. However, the aquatic–terrestrial interface offers a natural boundary similar to the one between agroecosystems and their neighboring non-crop habitats that can provide useful insights to the challenges facing growers. Research of the exchanges between water and land suggests general biological and physical processes that govern the movement of organisms between disparate habitats. We propose that like aquatic insects moving from water to land, natural enemy dispersal from non-crop donor habitats into recipient crop patches on the landscape is a function of (1) the production of natural enemies in the source habitat which establishes the abundance of organisms that can disperse, (2) how and why mobile natural enemies disperse themselves into neighboring recipient habitats, and (3) the configuration of donor and recipient habitats on the landscape. We suggest that conservation biological control practitioners can focus on these main components of natural enemy production and dispersal to predict the effectiveness of conservation biological control measures and guide their adaptation to future global change.     

Mechanisms for flowering plants to benefit arthropod natural enemies of insect pests： Prospects for enhanced use in agriculture

Reduction of noncrop habitats, intensive use of pesticides and high levels of disturbance associated with intensive crop production simplify the farming landscape and bring about a sharp decline of biodiversity. This, in turn, weakens the biological control ecosystem service provided by arthropod natural enemies. Strategic use of flowering plants to enhance plant biodiversity in a well-targeted manner can provide natural enemies with food sources and shelter to improve biological control and reduce dependence on chemical pesticides. This article reviews the nutritional value of various types of plant-derived food for natural enemies, possible adverse effects on pest management, and the practical application of flowering plants in orchards, vegetables and field crops, agricultural systems where most research has taken place. Prospects for more effective use of flowering plants to maximize biological control of insect pests in agroecosystem are good but depend up on selection of optimal plant species based on information on the ecological mechanisms by which natural enemies are selectively favored over pest species.     

Hibernation of predatory arthropods in semi-natural habitats

Non-crop habitats provide important resources for natural enemies. Many natural enemies hibernate in non-crop habitats, from which they may colonise arable fields in the spring. Spring colonisation ensures annual repopulation of the crop with natural enemies, allowing them to keep pace with the development of pest populations. The availability of non-crop habitats can, therefore, be crucial to successful conservation biological control. We quantified the density of overwintering natural enemies near organic Brussels sprout crops in five different non-crop habitats (short grassy field margin, herbaceous field margin, herbaceous field margin under a tree line, ditch and forest). Soil and litter samples of non-crop habitats were taken at two sites. One site was located in an open agricultural landscape, the other in a landscape dominated by mixed forest. Insects belonging to Staphylinidae, Araneae, Carabidae, Coccinellidae and Dermaptera were the most abundant. Mean densities of predatory arthropods were higher in the open agricultural landscape (290 predators m⁻²) than in the forested landscape (137 predators m⁻²). Herbaceous habitat types supported the highest densities of overwintering predators (up to 400 predators m⁻²), whereas densities in the forest were lowest (10 predators m⁻²). These results indicate that herbaceous non-crop habitats are important refugia for predators and may play a vital role in conservation biological control. Handling Editor: Arne Janssen.     

Sustainable pest regulation in agricultural landscapes: a review on landscape composition, biodiversity and natural pest control

Agricultural intensification has resulted in a simplification of agricultural landscapes by the expansion of agricultural land, enlargement of field size and removal of non-crop habitat. These changes are considered to be an important cause of the rapid decline in farmland biodiversity, with the remaining biodiversity concentrated in field edges and non-crop habitats. The simplification of landscape composition and the decline of biodiversity may affect the functioning of natural pest control because non-crop habitats provide requisites for a broad spectrum of natural enemies, and the exchange of natural enemies between crop and non-crop habitats is likely to be diminished in landscapes dominated by arable cropland. In this review, we test the hypothesis that natural pest control is enhanced in complex patchy landscapes with a high proportion of non-crop habitats as compared to simple large-scale landscapes with little associated non-crop habitat. In 74% and 45% of the studies reviewed, respectively, natural enemy populations were higher and pest pressure lower in complex landscapes versus simple landscapes. Landscape-driven pest suppression may result in lower crop injury, although this has rarely been documented. Enhanced natural enemy activity was associated with herbaceous habitats in 80% of the cases (e.g. fallows, field margins), and somewhat less often with wooded habitats (71%) and landscape patchiness (70%). The similar contributions of these landscape factors suggest that all are equally important in enhancing natural enemy populations. We conclude that diversified landscapes hold most potential for the conservation of biodiversity and sustaining the pest control function.     

定量评价天敌昆虫控害功能的稳定同位素方法

天敌在区域性多作物农田景观系统中辗转捕食害虫,对调节和控制害虫种群数量发挥着非常重要的作用。明确天敌昆虫的食物来源和扩散规律是定量评价其控害功能的重要环节。其中,稳定同位素标记方法是追溯生物个体的食物来源和探究其运动规律的重要手段。本文首先介绍该标记方法的基本原理,接着以天敌昆虫龟纹瓢虫Propylea japonica(Thunberg)为例,应用稳定同位素碳标记方法追溯其在棉花和玉米农田景观系统中取食来源与食物比例;最后叙述了稳定同位素方法的应用前景和存在的问题。     

Reprint of: Biological control of rice insect pests in China

Rice is one of the most important food crops in the world. China has the second largest area of the rice growing in the world and the highest yield of rice produced. Infestation by insect pests, especially rice planthoppers, stem borers and leaf folders, is always a serious challenge to rice production in China. Current methods for controlling insect pests in China mainly include good farming practices, biological control, breeding and growing resistant varieties, and the use of chemical insecticides. However, for farmers, the favorite method for insect pest control is still the application of chemical insecticide, which not only causes severe environmental pollution and the resurgence of herbivores but also reduces populations of the natural enemies of herbivores. To control insect pests safely, effectively and sustainably, strategies encouraging biological control are currently demanded. Here we review the progress that has been made in the development and implementation of biological controls for rice in China since the 1970s. Such progress includes the species identification of the natural enemies of rice insect pests, the characterization of their biology, and the integration of biological controls in integrated pest management. To develop effective ecological engineering programs whose aim is to implement conservation biological controls, further research, including the evaluation of the roles of plants in non-crop habitats in conservation biological controls, volatiles in enhancing efficiency of natural enemies and natural enemies in manipulating insect pests, and education to increase farmers’ knowledge of biological controls, is proposed.