【作者】 姚凤銮；

【导师】 尤民生；

【作者基本信息】 福建农林大学 ， 农业昆虫与害虫防治， 2012， 博士

【摘要】 稻田生态系统生物多样性的减少是导致害虫大发生的重要原因之一,提高稻田生态系统生物多样性有助于害虫持续控制。非稻田生境尤其是非作物生境对天敌的保护作用已经得到证实。然而,利用多种作物进行配置种植,以多样化稻田生境进行水稻害虫生态治理的研究鲜见报道。因此,本文选取大豆和玉米作为伴生作物,以大豆或玉米与水稻相间排列的种植方式,提高稻田生境的多样性,以期达到保益控害的目的。在2008年和2009年,我们采用吸虫器和人工拨查的方法调查了不同类型稻田节肢动物群落,将稻田节肢动物群落划分为蚂蚁、食腐者、植食者(包括钻蛀类、咀嚼类和刺吸类)、寄生者、重寄生者、捕食者(包括捕食性昆虫和蜘蛛)、游走类和天敌共13个功能团,分析了稻田节肢动物群落的物种组成、结构和时序动态；应用陷阱法(针对蚂蚁、捕食者、捕食性昆虫和蜘蛛)、透明粘板法(针对寄生者、重寄生者和植食者)和马氏网法(针对寄生者、重寄生者、捕食者、捕食性昆虫、蜘蛛和天敌)分别监测在生境间迁移的节肢动物功能团,分析功能团物种丰富度、丰盛度和时序动态。主要研究结果如下：(1)与水稻单作相比,多作稻田在一定程度上提高了节肢动物群落及节肢动物功能团的物种丰富度。但是,除了2009年增种大豆稻作系统的稻田(RS)较单作稻田(RMon)显著增加了节肢动物群落、植食者、钻蛀类和蜘蛛的物种丰富度外,多作稻田与单作稻田的节肢动物群落及节肢动物功能团的物种丰富度差异均不显著。多作不影响功能团的物种丰富度消长动态趋势和相对多度分布。(2)除了2009年增种玉米稻作系统的稻田(RC)较RMon显著减少刺吸类、捕食者以及天敌的个体数量外,稻田节肢动物各功能团的个体数量不受增种玉米的多样化种植的影响。除了在2009年RS较RMon显著提高腐食者、植食者和钻蛀类的个体数量外,稻田节肢动物各功能团的个体数量不受增种大豆的多样化种植的影响。多作没有显著减少植食者的个体数量,也没有显著增加天敌的个体数量。(3)不同类型稻田节肢动物群落的总物种数(S)与总个体数(N)的比S/N仅在2009年差异显著,且以RC的S/N显著高于RMon和RS,RS与RMon的差异不显著。在2008年和2009年,不同类型稻田节肢动物群落的天敌物种数(Sn)与植食者物种数(Sp)的比Sn/Sp均差异不显著。RC仅在2008年较RMon显著提高天敌个体数(Nn)与植食者个体数(Np)的比,即益害比Nn/Np,而RS与RMon在两年中的差异均不显著。(4)多作可以提高稻田节肢动物群落的物种等级—相对多度分布的均匀性。不同类型稻田节肢动物群落及各功能团的物种等级—累积相对多度分布差异不显著。(5)不同类型稻田之间节肢动物群落及功能团的Jaccard相似性差异均不显著,Jaccard相似性平均值在0.46-0.73之间。除2009年节肢动物群落和游走类的Morisita-Horn相似性差异显著外,不同类型稻田之间节肢动物群落及功能团的Morisita-Horn相似性差异不显著。除2009年RS与RMon以及RS与RC的游走类相似性平均值少于0.23外,两年间不同类型稻田之间节肢动物群落及功能团的Morisita-Horn相似性平均值在0.53-0.98之间。(6)多作比单作稻田系统中迁移的节肢动物功能团物种数更少,但是多作系统与单作系统的物种丰富度显著性差异仅体现在：a)地面陷阱监测发现,在2008年,多作系统中迁移的捕食性昆虫物种丰富度显著少于水稻单作系统,增种玉米的稻作系统中迁移的蜘蛛物种丰富度显著少于水稻单作系统；b)透明粘板的监测发现增种玉米的稻作系统中迁移的重寄生者和寄生者物种丰富度显著少于水稻单作系统；c)马氏网监测发现增种玉米的稻作系统中迁移的钻蛀类物种丰富度显著少于水稻单作系统。(7)多作系统中迁出稻田进入大豆或玉米的天敌个体数量并未显著多于单作系统中同方向移动的天敌个体数量。而迁入稻田的天敌个体数量仅以马氏网监测的寄生者在增种玉米稻作系统中的显著多于水稻单作系统。迁入和迁出稻田的刺吸类、刺吸类中的稻叶蝉以及稻叶蝉中的白翅叶蝉个体数量均以在增种大豆的稻作系统中迁移的分别显著多于在增种玉米的稻作系统和水稻单作系统中同方向移动的刺吸类、稻叶蝉和白翅叶蝉的个体数量。由于白翅叶蝉在稻田稻叶蝉中相对多度很小,因此大豆虽能促进白翅叶蝉在大豆田和稻田之间移动,却不能显著提高稻田中以二点叶蝉为主的稻叶蝉的个体数量。(8)与RMon相比,RS的稻飞虱个体数量在2008年更多,而在2009年则更少,但均差异不显著。而RC可以显著减少稻飞虱的个体数量,比RMon少26%-48%。RC对稻飞虱种群数量的抑制作用并不是由玉米对天敌的促进作用引起的。不同稻作系统中稻飞虱及其天敌在生境间的移动个体数量差异不显著,而且移动的稻飞虱数量极少。总之,与RMon相比,RC在2008年显著提高S/N,在2009年显著减少刺吸类的个体数量并显著提高益害比Nn/Np。另外,RC在两年的试验中均显著减少稻飞虱的个体数量。因此,本试验中玉米及其多样化稻田生境的种植方式,包括种植时间和种植布局均值得进一步研究,以探明其影响稻田害虫天敌的具体机制,为水稻害虫的生态治理和水稻的可持续生产提供科学依据。更多还原

【Abstract】 The loss of biodiversity in rice ecosystems is one of the main causes of rice insect pest out-breaks. Methods of biodiversity enhancement of rice ecosystems have therefore been promotedunder integrated pest management and other sustainable management practices. Non-rice habi-tats, especially non-crop habitats surrounding rice fields, were shown to be important to the nat-ural enemies of insect pests. However, few attempts have been made to evaluate the ecologicalrole of more profitable crops that could be used to diversify rice ecosystems and aid in naturalenemy conservation and insect pest suppression. In2008and2009, soybean and corn intercropswere examined for their potential to diversify rice ecosystems and enhance insect pest manage-ment. The composition, structure, temporal dynamics and movements of arthropod guilds withinarthropod communities were evaluated using sampling methodologies that included vacuumsampling and directional traps (pitfall, sticky and malaise). Arthropod communities were dividedinto13guilds: ants, detritivores, herbivores (including chewers, miners and sap-suckers), parasi-toids, hyperparasitoids, predators (including predatory insects and spiders), tourists and naturalenemies.The species richness of each arthropod guild in the rice fields was slightly higher in diculturesystems than in monoculture systems. When compared to the species richness of arthropodguilds in rice fields in rice monoculture systems (RMon), a significant improvement in speciesrichness was recorded in2009among herbivores, miners and spiders in rice fields in rice-soybeansystems (RS). However, the diversification of the rice ecosystems had minimal effects on thetemporal dynamics of species richness and the relative abundance of each arthropod guild.In contrast, rice fields in rice-corn system (RC) showed no significant change in the abun-dance of arthropod guilds except for sap-suckers, predators and natural enemies, all of whichshowed significantly higher abundance in RC than in RMon in2009. There was no significant dif-ference in the abundance of arthropod guilds between RS and RMon except that the abundancesof detritivores, herbivores and miners were significantly higher in RS than in RMon in2009. Poly-cultural manipulation did not significantly lower the abundance of herbivores, nor did it signifi-cantly increase the abundance of natural enemies.In2009, the value of the ratio of arthropod species richness (S) to the abundance of arthro-pods (N), S/N, was significantly higher in RC than in RMon and RS, and there was no significantdifference in the value of S/N between RMon and RS. In2008and2009, there were no significantdifferences in the value of the ratio of species richness of natural enemies (Sn) to species richness of herbivores (Sp), Sn/Sp, in rice fields under different cropping systems. However, the value of theratio of the abundance of natural enemies to the abundance of herbivores, Nn/Np, was signifi-cantly higher in RC than in RMon in2008, although there were no significant differences in thevalue of Nn/Npbetween RS and RMon in either2008or2009.The species abundance patterns for all arthropods as indicated by the species rank/relativeabundance curves was significantly different in rice fields under different cropping systems; thedistribution of the species abundance was more consistent in diculture than in rice monoculture.However, the cumulative species abundance curves showed that there were no significant dif-ferences in the distribution of species abundance for the arthropod communities or guilds in ricefields under different cropping systems.The Jaccard similarity coefficients for the arthropod communities and guilds in the rice fieldswere not significantly different among the different cropping systems, with mean coefficient val-ues falling between0.46and0.73. Similarly, no significant differences in the Morisita-Horn simi-larity coefficients were found for the arthropod communities and guilds in the rice fields underdifferent cropping systems, except for the total arthropods and tourists in2009. The mean valuesof the Morisita-Horn similarity coefficients for the arthropod communities and guilds fell be-tween0.53and0.98; the similarity values for tourists were less than0.23between RS and RMonand between RS and RC.Species richness based on the movement of arthropod guilds was lower, but not significant,in diculture systems than in rice monoculture systems. In2008, the species richness of predatoryinsects sampled by pitfall traps was significantly lower in diculture than in rice monoculture, andthe species richness of spiders was significantly lower in rice-corn systems than in rice monocul-ture systems. The species richness of hyperparasitoids and parasitoids sampled by sticky trapswas significantly lower in diculture than in rice monoculture, as was the species richness of min-ers sampled by malaise traps in rice-corn systems relative to rice monoculture.The abundance of emigrant predators and parasitoids was not significantly increased in di-culture than in rice monoculture. The abundance of immigrant natural enemies was not signifi-cantly higher in diculture than in rice monoculture with the exception of the abundance of immi-grant parasitoids, which was significantly higher in rice-soybean systems than in rice monoculturesystems. The abundance of emigrant and immigrant sap-suckers, rice leafhoppers and Ery-throneura subrufa was significantly higher in rice-soybean systems than in rice-corn systems andrice monoculture systems. However, the number of rice leafhoppers (predominantly Cicadulafasciifrons), was not significantly different under different cropping systems. Compared to RMon, RS had lower rice planthopper abundance in2008, but higher abun-dance in2009, though neither value was significantly different. The abundance of rice planthop-pers was significantly reduced in RC than in RMon and RS, where RC had26%47%fewerplanthoppers than RMon. However, neither parasitoid nor predator numbers were affected bypolycultural manipulation. There were no significant differences in the directional movements ofplanthoppers or natural enemies between crop subplots in the different cropping systems. Ingeneral, the movement of planthoppers was very limited.Overall, those rice fields with corn intercrops significantly improved the S/N and Nn/Npval-ues in2008and2009, respectively; rice fields with corn intercrops had a lower abundance ofplanthoppers, which contributed to lower sap-sucker abundance in RC than in RMon in2009. Thisstrategy could therefore be useful as part of an ecologically based pest management strategy forthe sustainable production of rice.更多还原