上海地区花卉节肢动物群落组成调查

2006年2月至2007年1月对上海地区60余种花卉生境中节肢动物群落组成进行了调查,把采集的节肢动物按营养关系分为植食类、捕食类、寄生类、其它类等4个功能团。根据鉴定结果,植食类共121种,捕食类22种,寄生类12科,其它类13科。其中,16种节肢动物为上海地区首次报道。植食类、捕食类、寄生类和其它类的相对丰富度分别为78.10%、5.61%、2.44%和13.85%。保护花卉生境中的捕食性和寄生性天敌种类是花卉生产生态化管理的重要任务之一。     

转cry1 Ab基因粳稻对稻田节肢动物群落的影响

在将稻田节肢动物群落按营养关系分为植食类、寄生类、捕食类、腐食类和其他类等5个功能团的基础上,从功能团优势度、群落结构参数及群落相异性等方面,经2年3点的调查就2个转cry1Ab基因粳稻（Bt粳稻）品系KMD1和KMD2对稻田节肢动物群落结构的影响做了评价。结果表明：在大多数情况下,Bt粳稻与对照间各功能团优势度、群落结构参数[物种丰富度（S）、Shannon-Wiener多样性指数（H′）、均匀性指数（J）、优势集中性指数（C）]及其时间动态无明显差异;Bt粳稻与对照间植食类、寄生类、捕食类亚群落,及整个节肢动物群落的相似性也较高。综合分析认为,Bt粳稻对稻田节肢动物群落结构无明显的负面影响。     

群落结构特征参数对葡萄园节肢动物群落作用的比较

利用主成分分析法,对葡萄园节肢动物群落、植食类亚群落、捕食类亚群落的特征参数进行分析.结果表明,葡萄园节肢动物群落、植食类亚群落、捕食类亚群落特征向量矩阵中第1主分量综合指标贡献率依次为66.70%、73.39%和54.17%.节肢动物群落的总个体数N、Hill多样性指数N₁、Hill多样性指数N₂和McIntosh指数D_mc的标准回归系数绝对值较大,对群落贡献大;植食类亚群落的N、N₂、N₁和物种数S的标准回归系数绝对值较大,对植食类亚群落贡献大;捕食类亚群落的N₂、N₁、Shannon-Wiener多样性指数H'和丰富度R的标准回归系数绝对值较大,对捕食类亚群落贡献大.综合分析,多样性指数N₁和N₂对3种类型群落贡献较大.     

4种生态类型稻区节肢动物群落的基本组成与结构特征分析

根据在浙江富阳、河南郑州、江苏句容和湖南长沙的连续田间调查,稻田节肢动物群落的组成依生态学上的营养关系分为植食类（害虫）、捕食类和寄生类（天敌）、以及腐生类和水生类（与水稻关系不甚密切,但可作为天敌的猎物）等。进一步分析显示,不同稻区的节肢动物群落的种－丰盛度关系适于用对数正态分布（Ｌｏｇｎｏｒｍａｌｄｉｓｔｒｉｂｕｔｉｏｎ）模型描述,单一作物生长季节中取样总计少于１０个个体的物种所占比例为４３．７６％－７１．９１％。不同类群的相对丰盛度因地而异,且可是水生类的摇蚊（富阳早稻田）、白背飞虱和褐飞虱（富阳晚稻、句容、长沙）、黑尾叶蝉（郑州）或腐生类的弹尾虫（句容）。多样性（以Ｎ＿１表示）的高低顺序为郑州（２８．５６）＞富阳晚稻（２２．４３）＞句容９１（１１．０８）＞富阳早稻（６．４３）,句容９２（６．８０）,和长沙（６．７２）。极丰盛种所包括的个体数占总个体数量的比例在６９％－８０％之间,具有普遍性的丰盛种有猎物类的褐飞虱、白背飞虱、蚊类、弹尾虫以及捕食类的狼蛛、黑肩绿盲蝽和尖钩宽蝽等,构成了稻田节肢动物群落组成及功能作用的主体。     

转cry1Ab/cry1Ac基因籼稻对稻田节肢动物群落影响

将稻田节肢动物群落按营养关系划分为5个功能团,即植食类、寄生类、捕食类、腐食类和其它类,从功能团优势度、功能团内科组成及其优势度、群落主要参数及群落相异性等方面,经两年四点的调查就2个转cry1Ab/cry1Ac基因籼稻（Bt水稻）品系TT9.3和TT9.4对稻田节肢动物群落的影响作了较系统评价。植食类、寄生类和腐食类功能团内某些优势科的优势度在Bt水稻田与对照（IR72）田之间有时呈显著或极显著差异,如Bt水稻田中茧蜂或姬蜂科的优势度有时明显低于对照。但是,在大多情况下Bt水稻田与对照田之间功能团优势度、功能团内科组成及其优势度、群落主要参数（物种丰富度、Shannon-Wiener多样性指数、均匀性指数、优势集中性指数）及其时间动态基本无明显差异;Bt水稻田与对照田间植食类、寄生类、捕食类亚群落和整个节肢动物群落的相异性大多较低。可见,Bt水稻对稻田节肢动物群落基本无明显的负面影响。     

间种牧草枣林捕食性节肢动物群落结构的动态

应用群落结构特征参数与主分量分析,对间种不同牧草枣林中捕食性节肢动物群落的结构和动态进行了研究.结果表明,蜘蛛与捕食性昆虫是间种牧草枣林的主要捕食性节肢动物群落,其相对丰盛度分别为48.3%～52.7%和38.8%～ 44.4%.间种不同牧草枣林捕食性节肢动物群落主要类群的平均密度、多样性和均匀度有明显差异(P<0.05),表现为间作百脉根枣林>紫花苜蓿枣林>扁茎黄芪枣林>白三叶枣林,优势集中性指数为间作白三叶枣林>扁茎黄芪枣林>紫花苜蓿枣林>百脉根枣林.各处理枣林中捕食性蜘蛛类的平均密度明显(P<0.05)高于捕食性昆虫类.瓢甲类、蝽类、蛇蛉类、草蛉类、蟹蛛类、圆蛛类和植绥螨类的个体数量在间种牧草枣林捕食性节肢动物群落中起主导作用.     

不同抗性品种稻田捕食性节肢动物的群落结构

对3个类型稻田早、晚稻捕食性节肢动物群落调查,结果表明:共有捕食性节肢动物67种,丰富度以蜘蛛高于捕食性昆虫类;早稻高于晚稻;中抗品种高于抗虫和感虫品种。早稻以皿蛛科Linyphiidae的食虫沟瘤蛛UlmmeliatainsecticepesBoes.etStr.占优势,晚稻则以狼蛛科Lycosidae的相对丰盛度最高。早稻捕食性天敌数量动态以中抗品种峰期最长;感性样田中天敌平均密度与中抗样田差异不显著,与抗虫品种差异显著;捕食性节肢动物多样性随着品种抗性的增强呈降低趋势,优势度随着品种抗性的增强而增强。晚稻3个品种样田中天敌的平均密度差异不显著;各品种样田的多样性明显高于早稻,且波动幅度小于早稻,品种之间多样性差异较小,晚稻群落可能具有较高的稳定性。     

不同烟草品种烟田捕食性节肢动物群落的结构和动态研究

应用群落结构特性参数和主分量分析对Nc89、Nc82和K326烟田中捕食性节肢动物群落的结构和动态进行了研究.结果表明,蜘蛛和捕食性昆虫构成烟田主要捕食性节肢动物群落,其相对丰盛度分别为83.25%～86.87%和13.13%～16.38%.烟田捕食性节肢动物群落主要类群平均密度(头/8株)品种间差异显著,K326显著高于Nc82,Nc82显著高于Nc89.皿蛛和瓢虫的个体数量在烟田捕食性节肢动物群落中起主导作用.Nc89和Nc82烟田捕食性节肢动物群落的丰富度(S)差异显著,其它群落结构特性指数三品种烟田之间无显著差异.群落丰富度(S)和优势集中性(C)的时序动态三品种烟田呈低高低趋势,多样性(H')和均匀度(E)的时序动态三品种烟田呈高低高趋势.     

转cry1Ab基因粳稻对稻田节肢动物群落的影响

在将稻田节肢动物群落按营养关系分为植食类、寄生类、捕食类、腐食类和其他类等5个功能团的基础上,从功能团优势度、群落结构参数及群落相异性等方面,经2年3点的调查就2个转cry1Ab基因粳稻（Bt粳稻）品系KMD1和KMD2对稻田节肢动物群落结构的影响做了评价。结果表明：在大多数情况下,Bt粳稻与对照间各功能团优势度、群落结构参数［物种丰富度（S）、Shannon-Wiener多样性指数（H′）、均匀性指数（J）、优势集中性指数（C）］及其时间动态无明显差异;Bt粳稻与对照间植食类、寄生类、捕食类亚群落,及整个节肢动物群落的相似性也较高。综合分析认为,Bt粳稻对稻田节肢动物群落结构无明显的负面影响。     

不同抗性品系稻田捕食性节肢动物群落的结构和动态

通过野外调查,对粳籼８９,七桂早,七袋占３个不同抗性品种水稻田中捕食性节肢动物群落的结构,动态等方面进行了研究。结果表明：水稻品种抗性对捕食性节肢动物群落结构的影响不显著。高抗虫性品种样田中节肢类捕食性天敌的迁入虫口密度和总的虫口密度相对较低,群落物种丰富度,多样性,均匀指数也吾下降趋势。     

Arthropod communities in a Japanese cedar (Cryptomeria japonica D. Don) plantation: Abundance,biomass and some properties

Arboreal arthropod communities were censused by insecticidal knockdown in a plantation of Japanese cedar,Cryptomeria japonica, in central Japan from April 1983 to February 1985 at intervals of two months. All arthropods sampled were allocated to higher taxonomic groups or guilds and the composition of the communities was analyzed with respect to abundance, biomass and their seasonal trends. The total densities fluctuated seasonally from 200 to 3500 m⁻²; corresponding biomass values ranged from 7 to 600 mg fresh weight m⁻². Maximum density and biomass generally occurred in summer and were minimum in winter. The consistently dominant guild in terms of abundance were the detritivores, mostly comprising Collembola and oribatid mites, accounting for 36–93% of all arthropods; phytophages, predators and detritivores were major guilds in terms of biomass, showing average proportions of 27%, 23% and 20%, respectively. Biomass ratios of predators to prey were generally high in some canopy communities, suggesting the importance of predation pressure in regulating the population levels of arthropods in forests. Average individual size of predators was approximately proportional to that of prey, irrespective of tree locality. Soil arthropod communities maintained densities approximately 10²–10³ times as large as the corresponding canopy communities throughout the year. The seasonal variations in abundance were much greater in canopy than in soil communities.     

The invertebrate fauna on broom,Cytisus scoparius,in two native and two exotic habitats

This study quantifies the invertebrate fauna found on broom, Cytisus scoparius, L. (Link), in two countries where it grows as a native plant (France and England) and two countries where it grows as an alien plant (New Zealand and Australia). The data are used to test three hypotheses concerning the predicted differences in invertebrate community structure in native versus exotic habitats: (1) Are generalist phytophages dominant in exotic habitats and specialist phytophages dominant in native habitats? (2) Are there empty phytophage niches in exotic habitats? (3) As a plant species accumulates phytophages, do these in turn accumulate natural enemies? The broom fauna was sampled at five sites in each country by beating five broom bushes per site. The sampling efficiency of beating was quantified at one field site and it was shown to collect 87 % of invertebrate abundance, 95 % of invertebrate biomass and 100 % of phytophagous species found on the branches. Generalist phytophages were dominant on broom in exotic habitats and specialists dominant on broom in the native habitats. Thus, the two countries where broom grows as a native plant had higher numbers of total phytophage species and a higher abundance of specialist phytophages per bush. There was no significant difference in the average abundance of generalist phytophage species found per bush in native and alien habitats. Phytophages were assigned to seven feeding niches: suckers, root feeders, external chewers, flower feeders, seed feeders, miners and pollen feeders. Empty niches were found in the exotic habitats; species exploiting structurally specific parts of the host plant, such as flowers and seeds, were absent in the countries where broom grows as an alien plant. The pattern of niche occupancy was similar between native and exotic habitats when just the generalist phytophages were considered. As phytophage abundance and biomass increased, there were concomitant increases in natural enemy abundance and biomass. Thus, it appears that as plants accumulate phytophages, the phytophages in turn accumulate natural enemies and a food web develops around the plant. Moreover, in the native countries, the history of association between the natural enemies and their prey has been sufficient for specialist predators and parasitoids, feeding on the specialist phytophages, to have evolved.     

桃园节肢动物群落的多样性、均匀度和相对稳定性季节动态

对桃园节肢动物群落进行了系统调查,并对数据进行了数学分析．结果表明,群落与植食动物亚群落的多样性指数相关系数为0．9480,两者极显著相关;群落与捕食动物亚群落的多样性指数相关系数为0．7855,两者极显著相关;两个亚群落的多样性均与群落多样性有关,两个亚群落多样性指数间相关系数为0．6741,两者显著相关;群落多样性指数与群落均匀度指数问相关系数为0．7870,两者极显著相关;群落多样性指数与两个亚群落均匀度指数之间均不相关．群落多样性指数(H’),与捕食性动物个体数(Sd)和植食性动物个体数(Sz)之比值(Sd／Sz)相关系数为0．8112,两者极显著相关;与群落物种数(Sz)和个体数(Si)之比值(Sz／Si)相关系数为0．9188,两者极显著相关;与捕食动物类群(科)数(Spl)和植食动物类群(科)数(Szl)之比值(Spl／Szl)不相关。     

Field evaluation of effects of transgenic <Emphasis Type="Italic">cry1Ab/cry1Ac,cry1C</Emphasis> and <Emphasis Type="Italic">cry2A</Emphasis> rice on <Emphasis Type="Italic">Cnaphalocrocis medinalis</Emphasis> and its arthropod predators

The impacts of transgenic Bt rice on target pests and their predators need to be clarified prior to the commercialization of Bt rice. In this study, the percentages of folded leaves of three transgenic Bt rice lines and non-transgenic parental rice line caused by Cnaphalocrocis medinalis were studied over two successive growing seasons. In addition, the population densities, relative abundance and population dynamics of C. medinalis and four species of its natural arthropod predators were investigated at three sites in China. The results showed that rice line significantly affected the percentages of folded leaves and population densities of C. medinalis larvae. Significantly higher percentages of folded leaves were observed on the non-transgenic rice compared with the three transgenic Bt rice on most sampling dates. Significantly higher densities of C. medinalis larvae and higher relative abundance of C. medinalis within phytophages were found on non-transgenic rice compared with three transgenic Bt rice at different sites across the study period. The population dynamics of C. medinalis larvae were significantly affected by rice line, rice line×sampling date, rice line×year, rice line×sampling date×year. However, there was little, if any, significant difference in the relative abundance, population density and population dynamics of the four arthropod predators between the three Bt rice lines and non-transgenic rice. The results of this study indicate that the Bt toxin in transgenic Bt rice can effectively suppress the occurrence of C. medinalis, but has no significant effects on the occurrence of the four predatory arthropod species.     

Evaluation of Pesticide EVects on Arthropod Predator Populations in Soya Bean in Farmers' Fields

The impact of two insecticides applied at locally practised frequencies on the population fluctuations of soya bean arthropods was studied at two farmers' field sites in Indonesia. Temporal recovery was determined from observations taken consecutively at short intervals. Spatial recovery was determined from observations taken at diVerent distances from the unsprayed surroundings. Monocrotophos suppressed predaceous ants, spiders and beetles, but did not reduce all phytophages. Lambda-cyhalothrin had a large impact on generalist predators and suppressed phytophages. Multiple regression analysis showed that temporal recovery was low for generalist predators and highest for lepidopterous larvae, indicating a potential to resurge after spraying. Spatial recover was observed for spiders, beetles, crickets and lepidopterous larvae (Galerucinae and Empoasca sp.), indicating that the presence of refuge areas may encourage recovery. To reduce the dependency on insecticides, farmers require training in phytophage-predator-insecticide interactions through field exercises.     

Local predator composition and landscape affects biological control of aphids in alfalfa fields

The biological control service supplied to croplands is a result of the predator community present within a focal crop, which is likely influenced by surrounding landscape composition and configuration. In this study, using cage experiments in two regions near Santiago, we determined if predator communities supplied a significant biological control service in alfalfa fields, examined how the abundance of exotic and native coccinellids, as well as other key predator groups, influenced biological control of aphids and measured how landscape composition and heterogeneity at three spatial scales influenced this service. We found that predators significantly suppressed aphid populations in both regions, but the relative importance of predators versus landscape variables on biological control differed between regions. In the region where predators were abundant, biological control was higher and related to the abundance of native coccinellids and syrphids, highlighting the importance of native species as providers of crucial ecological services. In the region where predators were not abundant, biological control was lower, and it was related to landscape composition, being positively associated with the abundance of woodlots and urban habitats, and negatively associated with fruit crops in the landscape. Therefore, landscape effects on biological control service may be weaker than local factors, and only become important when local predator abundance is low.     

麦田昆虫群落结构及多样性的季节动态

通过2年对麦田昆虫群落的系统调查,共查得昆虫11目、62科1、13种,其中植食类51种、捕食类23种、寄生类24种、腐食和食血类15种,种类数和个体数分别占群落总数的45.13,20.35,21.24,13.27%和92.89,2.19,3.63,1.35%。麦田昆虫群落可划分为4个营养层、6个功能团和19个类群,麦长管蚜Macrosiphum avenae(Fabricius)是绝对的优势种,其数量变动决定着总群落结构和多样性的季节动态。麦田昆虫群落多样性表现为前期和后期高、中期低的时间格局,类群多样性与物种多样性的变化趋势最为相似,可用类群多样性代替物种多样性进行群落分析。     

Pairwise interactions between functional groups improve biological control

Ecologists have long debated whether predators primarily disrupt one another’s prey capture through interspecific interference, or instead complement one another by occupying different feeding niches. Resolution of this debate has been difficult because different experimental designs are typically used to study interference versus complementarity. We adopted a somewhat atypical approach, surveying communities of predatory insects on 73 free-growing Brassica oleracea plants, and then re-constructing each community in field cages to measure its impact on aphid prey. The predator communities naturally varied in species composition, richness, and relative abundance; in our experiment we kept total predator density constant to avoid confounding effects of differing overall abundance. The predator communities’ impacts on aphids differed by >10-fold. Using a generalized linear model, we found that pairings of several predators in the community improved aphid suppression while no pairings disrupted it. Indeed, accounting for the presence of the beneficial pairings provided more power than species richness to explain predators’ impacts on aphids. Altogether, our results suggest generally complementary or neutral, rather than disruptive, multi-predator effects in this community. Our approach may be useful for determining the frequency of complementary species-pairings in many other systems.