烟秆还田对水稻稻飞虱及其捕食性天敌田间种群动态的影响

烟秆还田是烟稻轮作种植系统中一种常用的农业措施之一。2015-2016年在广东南雄市烟稻轮作地区研究了不同烟秆还田方式、还田量以及耕作方式等对晚造水稻稻飞虱及其重要捕食性天敌田间种群动态的影响。结果表明,烟秆浅层还田处理水稻上稻飞虱数量低于深还田处理,但差异不显著;在水稻种植中后期,显著低于不还田处理;不同还田方式间对捕食性天敌田间种群影响差异不显著。烟秆不同还田量对稻飞虱及其捕食性天敌数量影响研究结果表明烟秆还田处理的田间稻飞虱数量要显著低于不还田对照处理,2015年和2016年,2.5倍烟秆还田处理的稻飞虱平均数量与对照相比分别减少52.9%和61.1%。1/2倍和1倍烟秆还田量处理与2.5倍还田量相比,差异虽不显著,但烟秆还田量大的处理其褐飞虱数量要低;捕食性天敌数量与还田量之间无显著相关性。浅耕和深耕条件下烟秆还田对稻飞虱及其捕食性天敌田间种群数量的影响都不显著。本研究结果将为烟秆综合利用和水稻害虫绿色防控提供科学依据。     

不同农事操作技术对稻田害虫和天敌种群动态的影响

【目的】通过分析常规稻作田、稻虾共作田和香根草Vetiveria zizanioides诱集田3种农事操作技术对水稻害虫及其天敌种群动态的影响,为湖北地区新型绿色农事操作技术防控田间害虫、天敌保育和稻田有害生物可持续治理策略提供重要依据。【方法】在水稻抽穗期,采用目测法、扫网法、盆拍法、剥查法对3种农事操作稻田(常规稻作田、稻虾共作田和香根草)内害虫(稻飞虱、稻叶蝉、稻螟虫)和天敌进行搜集和统计。【结果】香根草诱集田内稻飞虱种群数量显著低于稻虾共作田(P0.05),常规稻作田间稻叶蝉、稻螟虫种群数量显著高于稻虾共作田和香根草诱集田数量(P0.05);3种农事操作技术下稻田间天敌种类主要以捕食性天敌蜘蛛类、草蛉类、黑肩绿盲蝽Crytorrhinuslividipennis和青翅隐翅虫Paederus fuscipes为主。其中,稻虾共作田和香根草诱集田拟环纹豹蛛Pardosa pseudoannulata、拟水狼蛛Piratasubpiraticus和黑肩绿盲蝽Cyrtorhinuslividipennis种群数量显著高于常规稻作田(P0.05)。【结论】香根草稻作田间稻叶蝉、稻螟虫种群数量显著低于常规稻作田,稻虾共作田间稻叶蝉、稻飞虱种群数量显著低于常规稻作田;3种农事操作技术下稻田间天敌种类主要以捕食性天敌蜘蛛类、草蛉类、黑肩绿盲蝽为主。     

稻菜轮作对稻田褐飞虱和蜘蛛数量的影响

在广东省广州市花都区和白云区系统调查了稻菜轮作田、水稻连作田的水稻害虫褐飞虱Nilaparvata lugens(Stl)及其捕食性天敌蜘蛛的数量,结果表明:与水稻连作相比,花都区稻菜轮作模式总体上降低了褐飞虱数量,同期最高降低66.6%,对田间蜘蛛数量影响不明显;白云区的稻菜轮作模式也显著降低了褐飞虱的数量,同期最高降低56.3%,对蜘蛛数量的影响也不明显。稻菜轮作模式能有效降低田间褐飞虱数量,有利于水稻生产。     

不同稻菜邻作模式对稻纵卷叶螟、稻飞虱及其捕食性天敌的影响

为了探明不同稻菜邻作模式对稻区内主要害虫及其捕食性天敌的影响,对水稻-白瓜、水稻-番茄、水稻-玉米、水稻-苋菜、水稻-菜心和水稻-菠菜等6种稻菜邻作模式下稻区内稻纵卷叶螟、稻飞虱及食虫沟瘤蛛、拟水狼蛛、拟环纹狼蛛、蛸蟏和稻红瓢虫的发生动态及其种群消长规律进行了研究。结果表明:6种稻菜邻作模式均可以显著降低稻纵卷叶螟和稻飞虱数量;早稻生长期,水稻与白瓜和番茄邻作模式下,稻纵卷叶螟蛾量、虫卵量和稻飞虱数量最大降幅分别达84.3%、38.9%和24.3%;晚稻生长期,水稻与苋菜和菜心邻作模式下,稻纵卷叶螟蛾量、虫卵量和稻飞虱数量最大降幅分别达79.5%、49.8%和13.4%;水稻-白瓜和水稻-菜心邻作模式还可以显著增加捕食性天敌数量。因此,水稻-白瓜和水稻-菜心邻作模式最能发挥稻田控害保益功能。     

稻田养鸭对稻鸭复合系统中病、虫、草害及蜘蛛的影响

研究鸭子在稻鸭复合生态系统中对蜘蛛及病、虫、草害的影响。试验结果表明 :稻田中放入 4 5 0只鸭 / hm2 ,对农田杂草的控制率为 98.8% ;稻鸭共栖小区蜘蛛数量显著高于施药小区。高峰期蜘蛛量 ,稻鸭共栖小区比施药小区高 6 3.6 % ;第 4、第 5代稻飞虱虫量稻鸭共栖小区比对照小区分别下降 4 7.6 %、72 .8% ,稻鸭共栖对稻飞虱可以起到稳定、持续的控制作用 ;可减轻二化螟、纹枯病的发生量和发病程度约 5 0 .0 % ,对二化螟和纹枯病有较好的控制效果 ;稻鸭共栖对纵卷叶螟控制效果较差 ,水稻生长后期需结合采用药剂防治 ;稻鸭共栖可改变农田害虫、天敌的生存环境 ,减少用药次数 ,减轻农药对环境的污染 ,提高水稻产量和经济效益     

以蛛治虫对优化稻田生态系统的作用

我国稻田蜘蛛已知有 2 3科 1 0 9属 373种 ,其中东南、西南、华中、西北和东北稻区分别为 2 2 8、2 2 0、2 0 7、1 2 6和 97种 .田间优势种群较其它天敌相对稳定 ,蜘蛛与稻飞虱的种群数量季节消长和生态分布相关性强 ,彼此制约关系明显 .以蛛治虫 ,创造有利于蜘蛛发生发展的生态环境 ,大幅度减少了化学农药的用量 ,保护了其它天敌 ,发挥多种天敌对稻虫的自然控制力 ,减少了环境污染 ,优化了稻田生态系统 ,使之呈良性循环     

稻田食虫瘤胸蛛种群空间分布型研究

稻田蜘蛛是稻田生态系害虫的重要捕食性天敌类群,明了稻田蜘蛛各类群的田间分布特征,对制订开展保护和利用这类天敌的策略和措施是很为必要的。 国内报道经研究了解的有三化螟、玉米螟、东亚飞蝗等害虫的空间分布型,在生产实践中发挥了积极作用,并且在温室粉虱分布型研究中提出改进测定的方法。根据我们从1977年以来开展稻田生态系蜘蛛种群动态的研究,看出微蛛、狼蛛科等所属几个优势种群对稻叶蝉、稻飞虱的控制作用是明显的。与此同时,测定了优势种群的田间分布型,并对几种分布型的测定方法作了初步探讨。食虫瘤胸蛛     

利用农田蜘蛛治虫

蜘蛛是农作物害虫的重要天敌,在稻田、棉田、果园、茶园、森林及室内均有分布。农田蜘蛛常守在水稻、棉株的上中下部,以飞虱、叶蝉、稻纵卷叶螟、稻螟蛉等十多种害虫为食,它不为害水稻,不受气候变化的影响。在4月上旬至11月上旬——即早、晚稻全生育期,蜘蛛都能捕食害虫。据调查,在稻田中蜘蛛与害虫的效应指标达1∶4时,蜘蛛就能控制害虫的发生与发展。根据省农田蜘蛛治虫科研协作网(湘阴、湖南师范学院、酃县等三十四个单位)试验证明,利用农田蜘蛛治虫,能减少化学农药对环境的污染,有利人畜健康;能解决农药暂时的不足,节约成本,安全有效,简便易行,是植保工作中的一个新途径。     

湘桂走廊单双季稻混栽稻田稻纵卷叶螟、稻飞虱及其天敌的种群动态

2017年和2018年在处于湘桂走廊的广西兴安县设置田间小区试验,研究了单、双季稻混栽稻田中水稻"两迁"害虫及其天敌的种群动态。结果表明,早稻上稻纵卷叶螟Cnaphalocrocis medinalis Guenée基本为迁入型,中稻上为迁入+本地繁殖型或迁出型,晚稻上为迁出型。稻纵卷叶螟的落卵量在5月底至6月下旬为全年高峰,集中在早稻拔节期至孕穗期;这导致早稻田6月下旬至7月初卷叶发生严重。鉴定到稻纵卷叶螟寄生性天敌11种,其中幼虫寄生主要发生在早稻和中稻前期。稻飞虱种群数量在早稻和中稻田较高,早中稻上以白背飞虱Sogatella furcifera Horváth为主,晚稻上以褐飞虱Nilaparvata lugens St?l为主。捕食性天敌种群数量在水稻生育期的中后期较高,前期较低;晚稻田的蛛虱比高达1.4-6.3。这些结果表明,单、双季稻混栽时,早稻和中稻上"两迁"害虫发生为害较重,晚稻上较轻;这与水稻生产季节前期迁入的"两迁"害虫数量高有关,也与生产季节中后期天敌的控害作用增强有关。     

稻田蜘蛛与飞虱制约关系及其利用

1972—1991年间,我们对稻田蜘蛛及其相关害虫—褐稻虱进行了较为系统的调查研究。本文主要论述稻田蜘蛛种类多,发生量大,繁殖力强.与稻飞虱的季节消长、生态分布、变态类型相一致,彼此制约关系明显,有良好的保护利用价值。创造有利于蜘蛛发生发展的环境,合理施用化学农药,既是保护利用蜘蛛的有效途径,又可保护飞虱的其它天敌,发挥多种天敌联合控制飞虱的作用,在经济、生态与社会三方面都可收到显著效益。     

SIMULATION AND OPTIMAL MANAGEMENT OF THE PEST-NATURAL ENEMY-INSECTICIDE SYSTEM OF PADDY FIELDS IN MIDDLE SEASON RICE CROPPING REGION*

Abstract Investigations on the pest-natural enemy-insecticide system, including rice leaf roller-spider-tamaron and planthopper-spider-tamaron system, were carried out in the paddy fields in middle season rice cropping region. The relationship among insect pest, natural enemy and insecticide were studied based on the principle of the pest management system engineering. The optimal management models of the two systems were developed. Their diagrams of optimal feedback control strategy were contoured for computer monitoring of the pest-natural enemy-insecticide system. The population densities of pest and natural enemy in the future could be forecasted and the optimal strategy could be made when the current field densities of pest and natural enemy were input into the computer. The optimal performance index, which is a combination of the total cost of using the chemical and the total cost of pest damage to crops, for pest control is minimized. The objective of the system management is to drive the state of the system towards a beneficial equilibrium of the system generally. A comparison of the new IPM strategy with the ordinary strategy based on a single economic threshold is conducted in this paper. The optimal control strategies suggest that both pest and natural enemy populations should be controlled in the integrated pest management.     

Optimum timing for integrated pest management: Modelling rates of pesticide application and natural enemy releases

Many factors including pest natural enemy ratios, starting densities, timings of natural enemy releases, dosages and timings of insecticide applications and instantaneous killing rates of pesticides on both pests and natural enemies can affect the success of IPM control programmes. To address how such factors influence successful pest control, hybrid impulsive pest-natural enemy models with different frequencies of pesticide sprays and natural enemy releases were proposed and analyzed. With releasing both more or less frequent than the sprays, a stability threshold condition for a pest eradication periodic solution is provided. Moreover, the effects of times of spraying pesticides (or releasing natural enemies) and control tactics on the threshold condition were investigated with regard to the extent of depression or resurgence resulting from pulses of pesticide applications. Multiple attractors from which the pest population oscillates with different amplitudes can coexist for a wide range of parameters and the switch-like transitions among these attractors showed that varying dosages and frequencies of insecticide applications and the numbers of natural enemies released are crucial. To see how the pesticide applications could be reduced, we developed a model involving periodic releases of natural enemies with chemical control applied only when the densities of the pest reached the given Economic Threshold. The results indicate that the pest outbreak period or frequency largely depends on the initial densities and the control tactics.     

Effects of crop species richness on pest-natural enemy systems based on an experimental model system using a microlandscape

The relationship between crop richness and predator-prey interactions as they relate to pest-natural enemy systems is a very important topic in ecology and greatly affects biological control services. The effects of crop arrangement on predator-prey interactions have received much attention as the basis for pest population management. To explore the internal mechanisms and factors driving the relationship between crop richness and pest population management, we designed an experimental model system of a microlandscape that included 50 plots and five treatments. Each treatment had 10 repetitions in each year from 2007 to 2010. The results showed that the biomass of pests and their natural enemies increased with increasing crop biomass and decreased with decreasing crop biomass; however, the effects of plant biomass on the pest and natural enemy biomass were not significant. The relationship between adjacent trophic levels was significant (such as pests and their natural enemies or crops and pests), whereas non-adjacent trophic levels (crops and natural enemies) did not significantly interact with each other. The ratio of natural enemy/pest biomass was the highest in the areas of four crop species that had the best biological control service. Having either low or high crop species richness did not enhance the pest population management service and lead to loss of biological control. Although the resource concentration hypothesis was not well supported by our results, high crop species richness could suppress the pest population, indicating that crop species richness could enhance biological control services. These results could be applied in habitat management aimed at biological control, provide the theoretical basis for agricultural landscape design, and also suggest new methods for integrated pest management.     

药剂处理对早稻田害虫天敌群落的影响

研究了三唑磷、杀虫双、阿维菌素和Bt+吡虫啉4种药剂处理对安徽江淮地区早稻田害虫 天敌群落的影响.结果表明,4种药剂处理对主要害虫的种群增长均有显著控制作用.三唑磷对群落多样性影响最大,其次是杀虫双和阿维菌素,其各处理区群落多样性平均值分别为1.545、1.562和1.691,均显著低于空白对照区（群落多样性平均值为1.897）;Bt+吡虫啉处理区群落多样性平均值为1.915,较空白对照区有所提高.药剂处理2周后,杀虫双处理区与阿维菌素处理区的群落组成最相似,三唑磷处理区与Bt+吡虫啉处理区最不相似.从群落稳定性和害虫可持续控制的角度看,4种药剂处理中以Bt+吡虫啉最优,而杀虫双和阿维菌素又稍优于三唑磷.     

水稻一稻纵卷叶螟-天敌系统的优化管理

本研究是在水稻群体生长模型和纵卷叶螟种群生命系统模拟模型的基础上进行的。通过耦台水稻与纵卷叶螟相互关系模型,模拟了水稻-纵卷叶螟-天敌系统动态,估算了在不同条件下纵卷叶螟的产量损失率,结合经济核算确定不同条件组合下的经济阈值(多维动态经济阈值)。我们从稻田生态系统的整体出发,给出了稻纵卷叶螟管理系统流程图,图中将决策区分为趋势决策和实时决策,寓测报和防治于一体,以优化管理为目的。     

综防区和化防区稻田害虫-天敌群落组成及多样性的研究

本文对长沙地区综合防治区和化学防治区稻田害虫-天敌群落特性进行了研究。 1.综防区害虫类、寄生昆虫类、蜘蛛类的种类丰富度几乎为化防区的2倍,捕食昆虫类是化防区的3倍以上。 2.利用双轴系统的二维排序表明:害虫一天敌群落的组成变化受它们所处环境和所处时间的影响,水稻品种对群落组成的影响并不重要。 3.综防区、化防区害虫-天敌群落的优势种基本一致。综防区群落各营养层的优势集中性较化防区小。 4.综防区群落的多样性高于化防区。早稻季内的多样性高于晚稻。杀虫药荆对群落多样性的影响是决定群落结构水平的重要因素,环境复杂程度主要影响群落中的稀有种类。综防区害虫-天敌群落的内部结构较化防区稳定,抗灾变能力和自动平衡的调节能力较化防区强。 5.多样性是种类丰富度和均匀性的函数。早稻季内影响多样性的主要成分是种类丰富度(占多样性变异的81.7～87.4％);晚稻季内影响多样性的主要成分是均匀性(占多样性变异的70.7—75.9％)。     

水稻挥发性信息化合物对昆虫的作用

植物挥发性化合物是联系植物、害虫和天敌间3层营养关系的关键信息因子。是害虫防治理论与实践的基础．首先,介绍了水稻挥发性信息化合物的基本化学特征及其在植食性昆虫和天敌昆虫寄主选择中的作用;其次,分析了水稻挥发性信息化合物的产生与作用机制及其生态学功能和水稻挥发性信息化合物研究中存在的问题;最后,展望了水稻挥发性信息化合物的研究前景．对水稻挥发性化合物的更进一步研究有两个方向,一是对存在于水稻体内,启动相关代谢途径的小分子信号物质的生理生化和分子生物学特性进行研究;二是研究捕食性节肢动物对信息化合物的接收、识别和学习等行为及与这些行为相关的生理生化和分子基础．     

不同干扰条件下枸杞园节肢动物群落结构与动态

2008年通过对宁夏银川地区不同干扰条件下枸杞园节肢动物群落的系统调查,共采集节肢动物151628头,鉴定出4纲27目76科167种,其中天敌亚群落61种,化防园23种,有机园30种,自生园61种,天敌总量的比例分别为10.87%、18.78%、70.34%。通过群落结构分析,自生园丰富度、个体数均明显高于化防园和有机园,有机园均匀度、多样性较高,而化防园丰富度、个体数指数都较低,而优势集中度高。通过主分量分析表明潜叶类害虫与刺吸类害虫是不同人工干扰条件下的主要害虫,刺吸类害虫成为发展有机枸杞的重要障碍,食花果类害虫具有较大的危害潜力;寄生类天敌、病原类天敌为自生园优势天敌,捕食类天敌是有机园、化防园的优势天敌,但化防园天敌作用较为微弱。自生园天敌亚群落与害虫亚群落第一对典型变量为V1=0.048x1-0.2533x2+0.5951x3+0.5207x4,W1=0.9021y1+0.0354y2+0.0223y3+0.1847y4-0.0591y5,相关系数为0.8635,化防园、有机园天敌亚群落与害虫亚群落第一对典型变量的相关系数分别为0.6826、0.7332。通过害虫-天敌亚群落的种群消长动态表明,天敌亚群落作为整体对害虫发挥着调控作用,自生园7-9月份寄生性天敌对刺吸式害虫的跟随作用很强,有机园较弱,化防园则不明显。     

Effects of bund crops and insecticide treatments on arthropod diversity and herbivore regulation in tropical rice fields

Ecological engineering using vegetable or flower strips is promoted as a potential pest management strategy in irrigated rice. Farmers in the Philippines often plant rice levees (bunds) with vegetables, particularly string beans (Vigna unguiculata [L.] Walpers) to supplement income, but without considering the potential for pest management. This study examines the effects of planted bunds on rice herbivores and their natural enemies. We compared arthropods in (a) rice fields that had string beans planted on bunds, (b) fields without string beans and without any insecticide applications and (c) fields without string beans but with insecticide treatments (standard practice). Rice yield was similar across all treatments; however, the vegetation strips produced an extra 3.6 kg of fresh string bean pods per metre of bund. There were no apparent increases in major natural enemy groups in fields with string beans compared to fields with conventional bunds. Fields with insecticide treatments had higher damage from leaffolders (Lepidoptera: Pyralidae). The sprayed fields also had lower parasitism of planthopper eggs and fewer predatory dragonflies and damselflies (Odonata). Furthermore, the mortality of planthopper (Delphacidae: Hemiptera) and stemborer (Pyralidae) eggs by parasitoids and predators was density dependent only in the unsprayed fields (with and without string beans). Our results demonstrate that planting string beans on rice bunds improves the productivity of rice farms, but our ecological engineering system did not appreciably affect natural enemy or herbivore abundance; however, chemical insecticides adversely affected pest regulatory ecosystem functions leading to higher pest damage.     

Relative importance of predators and parasitoids for cereal aphid control

Field experiments with manipulations of natural enemies of plant-feeding insects may show how a diverse enemy group ensures an important ecosystem function such as naturally occurring biological pest control. We studied cereal aphid populations in winter wheat under experimentally reduced densities of: (i) ground-dwelling generalist predators (mostly spiders, carabid and staphylinid beetles); (ii) flying predators (coccinellid beetles, syrphid flies, gall midges, etc.) and parasitoids (aphidiid wasps), and a combination of (i) and (ii), compared with open controls. Aphid populations were 18% higher at reduced densities of ground-dwelling predators, 70% higher when flying predators and parasitoids were removed, and 172% higher on the removal of both enemy groups. Parasitoid wasps probably had the strongest effect, as flying predators occurred only in negligible densities. The great importance of parasitism is a new finding for aphid control in cereal fields. In conclusion, a more detailed knowledge of the mechanisms of natural pest control would help to develop environmentally sound crop management with reduced pesticide applications.