棉田节肢动物群落的优势种分析

优势种作为生物群落的基本特征之一 ,是指那些由于其数量多、生物量大及其在食物链中有重要地位而对群落产生重大影响的物种。但在农田昆虫群落优势种分析中 ,通常是以数量的多少而确定其是否为优势种。事实上 ,尽管有些昆虫 (如害虫 )数量不多 ,不具备群落优势种的特征 ,但由于其个体大 ,对作物造成很大的危害。对于这类昆虫是否属于优势种类目前争论较大[1,5] 。棉花 (Ｇｏｓｓｙｐｉｕｍｈｉｒｓｕｔｕｍ )是我国重要的经济作物。其内节肢动物群落物种的组成与优势程度直接影响着棉花的生产。本文拟在系统调查棉田节肢动物群落的基础上 ,…     

吡虫啉对烟田节肢动物群落的影响研究

利用群落参数分析了吡虫啉对烟田节肢动物群落及其各亚群落的影响。结果表明,施药后对烟田节肢动物群落、害虫亚群落的物种数有一定的影响,对天敌昆虫和蜘蛛亚群落物种数的影响不明显。5月23日施药后至6月13日施药区(Ⅱ)和对照区节肢动物群落、害虫亚群落个体数均下降,下降程度施药区大于对照区。6月14日施药后施药区节肢动物群落、害虫亚群落个体数下降,对照区显著上升。两次施药对天敌昆虫和蜘蛛亚群落个体数的影响不明显,施药后一段时间内优势种烟蚜种群个体数量显著下降,使节肢动物群落和害虫亚群落优势集中性下降,多样性指数和稳定性增加。     

蚜虱净对苜蓿田节肢动物群落结构及动态的影响

以物种丰富度(S)、个体数量(N)、香农指数(Shannon’sindex,H′)和均匀度指数(E)作为多样性指标,研究了蚜虱净对苜蓿田节肢动物群落结构和季节动态的影响.结果表明:蚜虱净对天敌亚群落物种数的影响大于害虫亚群落,使总群落和害虫亚群落的优势集中性显著增加,但5月底施药对传粉蜜蜂类亚群落的优势集中性无显著影响.喷药初期,蚜虱净显著降低了蚜虫、蓟马等害虫数量,7d后蚜虫、蓟马等种群数量迅速回升,40d后超过对照;施药初期天敌亚群落的物种数大幅减少,多样性和均匀度指数较低,7d后天敌的物种数逐渐回升,到后期与对照田基本一致,但个体数量一直未恢复至对照水平.     

沈阳地区稻田节肢动物群落结构及群落生态研究

通过对沈阳地区稻田生态系统节肢动物群落结构及群落生态研究。共查得。属昆虫纲的有10个目的29科66种,其中天敌昆虫种类有7目20科51种,属蜘蛛纲的有蜘蛛目10科20种。用空间及时间生态位分析了害虫与天敌两个营养阶层间的关系。稻田生态系统节肢动物的多样性指数、均匀度与优势度分析表明,各类群落受外界干扰都很敏感,且表现一致性。依据节肢动物群落的结构及规律,结合沈阳地区水稻生长、栽培条件,用最优分割方法将稻田群落分为4个阶段,并提出了不同阶段害虫群落特点及害虫防治对策。     

间种牧草杂交杏李园节肢动物群落的结构及动态

对间种牧草杂交杏李园节肢动物群落结构与组成的系统定位观察与分析表明:杂交杏李园害虫种类有蚜虫类、叶螨类、食心虫类、介壳虫类、吮吸类、食叶类等,危害最为严重的是蚜虫类、叶螨类和食心虫类,这三种害虫的数量直接影响果实的产量。蓄草果园的天敌种类主要有蜘蛛类、瓢虫类和草蛉类,这三类天敌对主要害虫具有一定的控制作用,而且对维持果园害虫及其天敌之间平衡起着重要作用。对各功能类群的数量结构、生态优势度和多样性分析表明,间种牧草果园节肢动物群落结构比较稳定,各种群落指标相对平衡,天敌自然控害效果比较明显。分析认为果园有害生物综合治理应坚持大量利用自然天敌为主的生态控制的途径,不断优化果园生物群落结构、提高群落多样性和均匀度,减少群落生态优势度,增强群落自身调节控害能力,辅助使用农药,逐步达到生态控制果园有害生物的目的。     

稻田节肢动物群落不同取样方法的比较

<正> 稻田节肢动物群落研究是水稻害虫综合治理的非常重要的基础性工作。国内过去主要是用肉眼观察或盆拍结合扫网对群落进行数量研究,其主要缺陷为取样单位大小不统一,扫网因人而异,误差可能较大,给不同群落结构与功能的比较研究带来一定的困难;国际水稻所(IRRI)应用Farmcop吸虫器进行稻田群落取样,经我们使用,该种吸虫器用直流电源,吸力较小,费时费力,使用不便。我们采用南京农业大学由弥雾机改装的吸捕器进行水稻生长季节     

抗虫转基因水稻和化学杀虫剂对稻田节肢动物群落的影响

从功能团优势度、功能团内科组成及其优势度、功能团个体数量、群落主要参数及群落结构相异性等方面,就含crylAb／crylAc融合基因的Bt水稻和化学杀虫剂对稻田节肢动物群落影响进行比较研究．结果表明,与对照田相比,Bt稻田的节肢动物功能团组成及其优势度、各功能团内科组成及其优势度分布、功能团内个体数量的时间动态、群落参数(物种丰富度、Shannon-Wiener多样性指数、均匀性指数、优势集中性指数)及时间动态在大多情况下均无显著差异,两者间群落结构相似性较高．Bt水稻对稻田节肢动物群落基本无明显的负效应、而化防田的功能团优势度等群落特征指标与对照田相比,有时具有明显甚至显著的差异;群落结构相似性也较低．综合分析表明,Bt水稻对稻田节肢动物群落的影响明显弱于化学杀虫剂。     

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。     

菜田节肢动物群落特征及其多样性恢复的研究

探讨了化学杀虫剂对菜田节肢动物群落结构和多样性的影响以及停止化学杀虫剂使用后多样性的恢复,结果表明化学杀虫剂对菜田节肢动物群落的物种组成,多样性指数及物种分布的均匀性等均有影响,菜田节肢动物群落结构变化同害虫类,捕食性天敌和蜘蛛类的特征变化关系密切,经常使用化学杀虫剂的菜田与停止使用后的菜田相比,物种数量显减少,多样性指数降低,停止化学杀虫剂使用后,优势害虫的种群趋势指数明显降低,大敌对主要害虫的控制作用增强,节肢动物多样性指数增大,因此,限制化学杀虫剂的使用,恢复由于化学杀虫剂的使用而破坏了菜田环境,增强天敌对主要害虫的控制能力,这在菜田害虫生态控制中起着重要的作用。     

不同生境区稻田节肢动物群落相似性分析

根据不同生境区稻田节肢动物群落系统调查结果,应用组平均聚类分析法及主成分分析法,讨论节肢动物群落的相似（相异）性问题。结果表明：生境条件及管理措施的差异对群落的结构影响较为明显,不同生境区的稻田节肢动物群落,都能在一定距离取值时聚合成一类,而水稻品种对此影响较小。主成分分析结果由二维图表达已基本满足要求。结果说明大八镇生境区稻田节肢动物群落与岗列镇生境区稻田节肢动物群落差异较大,分别列于两个极端。海陵镇生境区稻田介于两者之间,而与岗列镇生境区稻田节肢动物群落重叠。与聚类分析结果有所差异。这可能与主成分分析法损失部分信息有关。     

稻田节肢动物群落营养层及优势功能集团的组成与多样性动态

该项研究通过系统调查,把稻田节肢动物群落按营养和取食关系划分为三个营养层(基位物种,中位物种,顶位物种)和不同的功能集团,在物种、功能集团和营养层三个组织层次水平上探讨了稻田节肢动物群落的结构和多样性,较全面地考察了整个群落中物种和功能集团在时间上的结构动态、功能关系和数量消长规律。结果表明：功能集团多样性与种多样性的变化趋势较一致,在群落研究中似乎可以用对功能集团的研究代替对种的研究,从而简化物种间复杂的网络关系,认为这是研究群落物种间功能关系的途径之一。营养层多样性在时间序列过程中波动性较小,所以可用于群落相似性和稳定性的分析。研究分析了中性昆虫对害虫调控的意义,认为对于天敌作用的评价应以整个群落为基础,全面考虑天敌、害虫、以及中性昆虫的数量、丰盛度、空间时间生态位等信息。     

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。     

Insect conservation and pest management

The issue of insect conservation in pest management has many conflicting aspects. For instance, it is desirable to conserve a pest residue in order to maintain natural enemy population and it is imperative to conserve natural enemies. However, conservation of pest species is not relevant if the pest species is an exotic invader and a candidate for eradication, mainly because eradication, if successful, achieves only regional extinction. Conservation of native pests depends, to a large extent, on whether the species is a direct pest of a high value crop or an indirect pest with an acceptable economic injury level. In this paper, integrated pest management is defined in terms of sustainable agriculture and the conservation of biodiversity, and give five premises that stress the level of disturbance of agricultural communities and the dynamics of pest status for arthropod species in the community. The possible impacts of the main integrated pest management tactics on arthropod conservation are tabulated and the results reached stress that diversification of agricultural systems through maximum use of native plants should benefit both integrated pest management and regional arthropod conservation.     

大豆田节肢动物群落优势种群时间生态位及营养关系分析

【目的】阐明大豆田节肢动物群落时间生态位及营养关系,为大豆害虫生态调控手段的实施提供坚实的理论依据。【方法】以大豆田节肢动物群落为研究对象,通过两年的田间系统调查分析。【结果】统计得到种类220余种,物种可分为天敌、害虫和中性昆虫3个类群,以天敌物种丰富度最高;害虫中以烟蓟马Thrips tabaci(0.36902)和大豆蚜Aphis glycines(0.13122)优势度最高,且有着较高的生态位重叠指数(0.8163),蚜小蜂Aphytis sp.和大草蛉Chrysopa septempunctata对害虫的时间生态位重叠指数很高,其他天敌如异色瓢虫Harmonia axyridis、龟纹瓢虫Propylaea japonica、黑带食蚜蝇Zyistrophe balteata和黑食蚜盲蝽Deraeocoris punctulatus等对害虫的重叠指数居中;大豆田中各类群构成错综复杂的食物网结构。【结论】综合考虑天敌的种群数量,确定捕食性天敌是控制害虫种群数量的有效天敌。研究可知不能单纯从时间生态位的重叠指数的高低来判断天敌的控制能力。     

猕猴桃园节肢动物群落重建及主要类群的生态位

为研究猕猴桃节肢动物群落重建过程和主要类群生态位移,本试验系统调查野生猕猴桃和人工栽植不同树龄(3年、9年、14年)猕猴桃园节肢动物群落,测定群落特征指标和主要类群的时空生态位。结果表明,群落包含3纲15目74科,约90种。不同桃园节肢动物群落的主要类群不同,各类群占群落总数的比例差异显著,野生猕猴桃园群落中各类群分布较均匀,栽植桃园群落中害虫比例较大。野生猕猴桃园和栽植猕猴桃园之间,群落的多样性指数、均匀度和优势度差异均极显著,群落稳定性表现为野生>9年>14年>3年。各类群的时空二维生态位也会随着栽植时间增长发生变化：蜘蛛和蝇类的生态位在不同树龄的猕猴桃园中都保持在较高水平;人工栽植初期,山楂叶螨和叶蝉占据的时空生态位较宽,成为优势类群,小薪甲与山楂叶螨生态位重叠较大,竞争激烈;随后,小薪甲和瘿蚊的时空二维生态位逐渐增大,到14年桃园中已经取代了山楂叶螨和叶蝉,成为主要害虫。总之,人工干扰的节肢动物群落重建是一个次级演替过程,与自然生态系统群落明显不同。     

井冈山森林凋落物分解动态及磷、钾释放速率

应用网袋分解法对井冈山地区亚热带常绿阔叶林、针阔叶混交林和高山矮林地上和地下(10 cm)2个分解组的叶凋落物进行了连续2年的分解试验,测定了凋落物的分解速率以及P、K元素的释放动态.结果表明: 3种林分叶凋落物残留率与时间呈负指数衰减关系.各林分凋落物干质量损失前期较快,第1年末两组平均质量损失率分别为50.6%(常绿阔叶林)、41.7%(针阔叶混交林)和40.13%(高山矮林),且地上组显著高于地下组;后期较慢,至第2年末2组平均质量损失率分别达到60.95%(常绿阔叶林)、57.06%(针阔叶混交林)和56.60%(高山矮林),均以常绿阔叶林、针阔叶混交林、高山矮林为序递减,地上组与地下组的差异不显著.根据Olson指数衰减模型对质量损失率结果进行拟合,发现3种林分样地上凋落物分解95%所需的时间(t_0.95)为6.8～9.9年,其大小排序为常绿阔叶林＜针阔叶混交林＜高山矮林.P在不同林分凋落物分解过程中均存在明显的净固持效应,其强度顺序为高山矮林＞针阔叶混交林＞常绿阔叶林,凋落物初始P含量和C/P可能是导致上述情形的原因.K在各林分的多数时间均表现为净释放.以试验末期的元素释放量计算,P的释放速率在地上组和地下组之间无显著差异,而K则为地上组显著高于地下组.     

Arthropod fauna of jarrah (Eucalyptus marginata) foliage in Mediterranean forest of Western Australia: Spatial and temporal variation in abundance,biomass, guild structure and species composition

Abstract A 2 year study (using a branch-clipping technique) of the arthropod fauna of jarrah crowns (14 m above ground level) in a 7500km² area centred on Manjimup, Western Australia, yielded 7461 individuals belonging to 396 species. Lepidoptera, Hemiptera and Araneae dominated the fauna in abundance and biomass but Lepidoptera less so in number of species. Consequently, leaf chewers, sapsuckers and predators were the dominant guilds. Most species showed great spatial and temporal variation in their occurrence, with some 73% being recorded on only one or two of the nine sampling occasions. In addition 77% of species were recorded on four or fewer of the 45 trees sampled. Crowns of these trees tended to have highly dissimilar assemblages of arthropods. Dissimilarity between trees was not predictable from the distance between them. Total species richness was greatest in samples collected in summer. Predators and sapsuckers tended to be the most speciose guilds. Within-stand differences were much less pronounced than between-stand differences: ants were more abundant on jarrah foliage within 2 m of ground level and the pest defoliator Uraba lugens (Lepidoptera, Noc-tuidae) was more abundant on foliage of jarrah pole crowns 14 m above ground. The most abundant arthropod, U. lugens, did not reduce appreciably the biomass or abundance of other arthropod groups present in jarrah pole crowns. This is consistent with the paradigm that competition between species of herbivorous insects is infrequent. After comparison with other studies in jarrah forest, we tentatively conclude that there is no single fixed pattern of organization or predictable assemblage of invertebrates on jarrah foliage.     

Tea: Biological control of insect and mite pests in China

Tea is one of the most economically important crops in China. To secure its production and quality, biological control measures within the context of integrated pest management (IPM) has been widely popularized in China. IMP programs also provide better control of arthropod pests on tea with less chemical insecticide usage and minimal impact on the environment. More than 1100 species of natural enemies including about 80 species of viruses, 40 species of fungi, 240 species of parasitoids and 600 species of predators, as well as several species of bacteria have been recorded in tea ecosystems in China. Biological and ecological characteristics of some dominant natural enemies have been well documented. Several viral, bacterial, and fungal insecticides have been commercially utilized at large scale in China. Progress in biological control methods in conjunction with other pest control approaches for tea insect pest management is reviewed in this article. Knowledge gaps and future directions for tea pest management are also discussed.     

Structural complexity of arthropod guilds is affected by the agricultural landscape heterogeneity generated by fencerows

Intensive farming imposes harsh conditions impeding the persistence of most arthropod species within crop fields. Hence, arthropods surviving the unfavourable conditions prevailing within crop fields may disperse towards nearby uncropped margins, such as fencerows. Here, we evaluate the influence of landscape heterogeneity on the abundance of different guilds, particularly herbivores and their natural enemies. Said heterogeneity mostly derives from fencerow network density. Hence, we developed an approach based on fitting linear‐mixed models to elucidate the effects of landscape heterogeneity and field position (fencerows and crop interiors) on arthropod diversity. Mixed models were fitted to arthropod data obtained by pitfall trap samplings in 36 crop fields. Arthropod communities were structurally and functionally more complex along fencerows than within nearby crop interiors. Arthropods abundance was modulated by landscape heterogeneity, increasing the abundance of natural enemies as the landscape heterogeneity increased. On the contrary, herbivores abundance decreased as landscape heterogeneity increased. Consequently, the ratio between herbivores and natural enemies also decreased as landscapes became more heterogeneous. Natural enemies with larger body sizes, mostly carabid beetles, were more sensitive to landscape homogenisation. Our study reveals that, despite the coarse‐grained landscapes in the Rolling Pampa, fencerow density appears as a key factor for structuring complex arthropod guilds in intensively farmed agricultural mosaics. In landscapes with higher density of fencerows, arthropods tend to concentrate along them, thus increasing the community structural complexity as well as the predation pressure over herbivores. This structural complexity of upper trophic levels enhances the ‘top‐down’ regulation of herbivore populations, consequently decreasing the probability of pest outbreaks within crop fields.