禾谷缢管蚜的空间格局及其抽样技术

以抽穗后的小麦为材料,用各种聚集强度指标对禾谷缢管蚜种群在麦田的分布进行测定．结果表明,在小麦灌浆初期及近收获时该蚜的空间格局呈聚集分布,在小麦灌浆中期呈均匀分布．空间格局变化的原因与麦田有蚜茎率有关．当有蚜茎率大于９３％时,该蚜的空间格局就由聚集分布转向均匀分布．最后提出了该虫的最适理论抽样数和以无蚜茎率确定防治指标     

肚倍蚜干母空间分布型与抽样技术

本文分析了肚倍蚜干母的空间分布型。结果表明肚倍蚜干母种群星聚集分布,同时符合奈曼分布和负二项分布。并分析了引起聚集分布的原因和提出了理论抽样方程。     

云南两个不同生态区玉米蚜种群动态研究

在2013年5-9月,采取5点取样,对云南省昭通温凉玉米种植区及普洱暖热玉米种植区玉米蚜种群动态进行定期、定点、定株的系统调查,明确云南省两种不同生态条件下玉米种植区玉米蚜发生规律及分布特征,为玉米蚜的防治提供理论依据。结果显示:昭通温凉玉米种植区玉米蚜在玉米各生育期均有发生;玉米蚜在抽雄散粉期主要集中在雄穗为害,籽粒建成期以后转移集中在苞叶及雌穗为害;玉米蚜在玉米田始终呈聚集分布,聚集度呈聚集—扩散—聚集趋势。普洱暖热玉米种植区玉米蚜种群数量在玉米进入籽粒建成期后才有所增长;玉米蚜在籽粒建成期以后主要集中在苞叶及雌穗上为害;玉米蚜在玉米田基本呈聚集分布,聚集度始终呈扩散趋势。两地玉米蚜自然种群消长、垂直分布动态,空间动态均具有一定差异,昭通温凉玉米种植区相对更适宜玉米蚜的发生。     

桃粉大尾蚜及其天敌空间格局的研究

<正> 桃粉大尾蚜 Hyalopterus amygdali Blanchard是桃树的常见害虫,重发年份不仅影响产量和品质,而且降低树势。桃粉大尾蚜的空间分布格局直接影响调查抽样结果的准确性。为了科学抽样,提高测极准确性,为适时开展防治提供依据,特开展本研究。     

间作与施用水杨酸甲酯对麦长管蚜及其主要天敌空间分布的影响

研究了小麦-油菜间作和田间施用水杨酸甲酯(MeSA)下麦长管蚜及其主要天敌种群的空间分布.结果表明:小麦-油菜间作和施用MeSA使麦长管蚜的空间分布发生改变.间作和施用MeSA均能降低麦长管蚜的聚集程度,并使之趋于均匀分布,二者同时作用效果更显著.小麦不同生育期天敌种群空间分布的变化趋势与麦长管蚜种群基本一致.研究结果可为确立麦长管蚜及其天敌的田间调查抽样方法和预测预报等提供依据.     

苹果绵蚜种群的空间分布型及其应用——Ⅰ.秋季种群

生物种群的空间分布是一种高度特化的生物学特性,是长期适应自然环境的结果。在理论上,研究种群的空间分布有助于理解种群的生态学特性以及种群与所处环境的相互关系;在实践中,种群的空间分布是确定生物统计分析的资料代换方法和制定抽样技术方案的依据。 苹果绵蚜Eriosoma lanigerum(Hausm.)是苹果树的毁灭性害虫。50年代云南仅昆明地区有苹果绵蚜的分布,现在苹果绵蚜已侵入到云南许多苹果产区。1978年苹果绵蚜侵入到丽江县,其危害相当严重。过去的工作主要集中在生物学和防治方面,空间分     

红腹缢管蚜空间分布型及抽样技术研究

对红腹缢管蚜的空间分布型及抽样技术进行了研究。 11组样本各项指标均符合聚集分布的检定标准。应用 Taylor幂法则、Iwao回归分析法 ,测定出红腹缢管蚜的空间格局是基本成份为个体群的聚集分布 ,聚集强度随种群密度的升高而增加。聚集原因是昆虫本身行为和环境因素综合影响的结果。应用 Iwao提出的 N=t2D2 (α+1x +β- 1) )公式 ,确定了在一定精确水平下的理论抽样数。当 t=1,m0 =2时 ,序贯抽样的上、下限为 :T(n) =2 n± 6 .8577n。     

居竹伪角蚜及其3种主要天敌的空间格局研究

对危害孝顺竹Bambusa multiplex的居竹伪角蚜Pseudoregma bambusicola及其3种主要天敌的卒间分布进行调查,聚集度指标表明竹蚜在竹林问为聚集分布,其种群密度在一定时间内较为稳定.天敌蚜厌蝶Taraka hama-da、赤星瓢虫Lemnia sauciaia和食蚜虻Asilichae.sp.在竹林中主要符合负二项式分布和P-E核心分布,为小均匀的聚集分布,存在由点片向四周扩散的现象,频次分析和聚集度指标的分析结果基本一致,其中瓢虫的聚集程度不及另外2种天敌的明显.对竹蚜和天敌的相关关系分析表明,仪食蚜虻的分布与竹蚜之间表现为负相关(r=-0.6341),食蚜虻的活动受蚜群分布的影响最大,而其余2种天敌的取食范围不受限制.     

温室瓜蚜种群动态的研究

瓜蚜AphisgossypiiGlover在温室黄瓜上的空间格局为聚集分布,分布的基本成分为个体群,聚集强度随密度的上升而下降;瓜蚜主要分布于中部和下部叶片。瓜蚜在温室黄瓜上呈指数增长,模型为Nt=0.1745e0.7414t(r=0.9676)。应用最优分割法将瓜蚜种群动态划分为3个阶段:初建期、发展期和高峰期。在种群初建期,有翅蚜开始迁入,数量较低,以扩散为主,分布不均匀,聚集强度较高;在发展期,瓜蚜种群不断繁殖扩散,分布日趋均匀,聚集强度逐渐下降;在高峰期,瓜蚜种群数量急剧增长到最高峰,分布至所有植株,聚集强度继续下降,此阶段后由于黄瓜植株受害枯萎,瓜蚜缺少食物而数量急剧下降。     

菜蚜二项式抽样设计及其精度分析

１９９０～１９９２年间对杭州市郊区青菜上桃蚜（Ｍｙｚｕｓｐｅｒｓｉｃａｅ）、萝卜蚜（Ｌｉｐａｐｈｉｓｅｒｙｓｉｍｉ）及其混合种群的田间近１００组调查数据,利用每样方（株）虫口不超过数阈值Ｔ（分别为０、１、５、１０、２０、３０、４０）头蚜虫的植株比例（ＰＴ）与种群密度（ｍ,头·株－１）的关系,通过拟合经验公式ｌｎ（ｍ）＝ａ＋ｂｌｎ［－ｌｎ（ＰＴ）］而设计的二项式抽样．通过对三者不同数阈值（Ｔ）的回归决定系数（ｒ２）、种群密度的回归估计方差（Ｖａｒ（ｍ））、抽样精度（以ｄ表示）和实际应用等的比较,结果表明当桃蚜种群处于较高密度即ｍ≥１０时,其理想的Ｔ值为３０;当萝卜蚜种群处于较高密度即ｍ≥５时,其理想的Ｔ值为１０;而它们的混合种群未得到其理想的Ｔ值．数阈值Ｔ为３０和１０可分别用于桃蚜和萝卜蚜的二项式抽样设计．而传统的二项式抽样即０～１抽样由于应用于小白菜上菜蚜的抽样设计时产生很大的误差,不宜采用．     

AM真菌对紫花苜蓿茎点霉叶斑病及豌豆蚜为害的影响

苜蓿茎点霉(Phoma medicaginis)叶斑病和豌豆蚜(Acyrthosiphon pisum)是紫花苜蓿(Medicago sativa)生产中重要的病虫害,在自然条件下常混合发生。本研究以紫花苜蓿为植物材料,探究接种AM真菌后,紫花苜蓿被苜蓿茎点霉侵染时,植物自身的防御机制,以及对后续豌豆蚜为害的影响,以期明确AM真菌对其调控机制。结果表明:AM真菌可显著降低植株茎点霉叶斑病病情指数(P<0.05); AM真菌促进了紫花苜蓿生长(P<0.05),改变了植株抗氧化酶(超氧化物歧化酶(SOD)和过氧化氢酶(CAT))活性以及植物激素信号物质(水杨酸(SA))含量(P<0.05);病原菌侵染会诱导植物抗氧化防御系统活性增强,包括过氧化物酶(POD)、SOD、CAT和多酚氧化酶(PPO)(P<0.05),从而增加植物对后续虫害的抗性; AM真菌在植物受到病原菌胁迫时会发挥积极作用,显著提高植株的SOD和CAT活性(P<0.05),有效抑制病原菌侵染对植株造成的危害;而蚜虫为害则进一步加重了植物受到的损害,抑制了AM真菌对植物抗病性的正向调控。研究结果对...     

Sequential sampling of Aphis gossypii Glover (Hemiptera: Aphididae) and Frankliniella schultzei Trybom (Thysanoptera: Thripidae) on cotton crop

The goal of this research was to use the sequential probability ratio test to establish a sequential sampling plan for Aphis gossypii Glover and Frankliniella schultzei Trybom infesting cotton. Field work was conducted at the agricultural experimental station of the Universidade Federal da Grande Dourados during the 2003/2004 and 2004/2005 agricultural years. Aphid colonies and individual thrips in the sampling area were counted and their numbers were recorded. The spatial distribution pattern of A. gossypii and F. schultzei in the cotton culture was aggregated. Sequential sampling plans were developed for aphids and thrips with type I and type II errors set at 0.1, common Kc = 0.6081 (aphids) and = 0. 9449 (thrips), and safety and management levels of 20% (aphids) and 40% (thrips) of infested plants. The sampling plans resulted in two decision boundaries for each species, as follows: the upper boundary, indicating when management (population control) is recommended: S1 = 4.6546 + 0.2849n (aphids), and S1 = 3.6514 + 0.1435n (thrips); and the lower boundary, indicating when population control is not necessary: S0 = -4.6546 + 0.2849n (aphids) and S0 = - 3.6514 + 0.1435n (thrips). The highest probability of error when making a decision was 3% for aphids and 2% for thrips, respectively. The maximum number of samples required to reach a decision was 63 for aphids and 95 for thrips.     

甘蓝和白菜上桃蚜种群的空间格局及其时序动态

1999-1992年在杭州郊区菜区连续调查了10茬结球甘蓝、19茬白菜上桃蚜Myzus Persicae种群的分布图式。利用这些数据计算出多项空间聚集指标,分析了各项指标与密度的相关性,然后选择受密度影响较小的负二项分布的K值,描述了种群的空间格局及其时序动态。两类蔬菜上桃蚜种群全年呈聚集分布;但聚集强度变化有明显的季节规律。一年中5月和11月前后有两个明显的扩散高峰;在蚜虫迁离本田的6～7月和重新迁入本田的9-10月前后则有两个聚集高峰。在一季作物上的聚集强度随时间的变化过程因季节而异,春夏季为高一低一高,秋冬季从高往低呈持续下降,而冬春季则呈上下随机波动趋势,文中最后对桃蚜种群空间图式及其时序动态特征的成因,尤其是气温和植株营养条件变化的影响进行了讨论。     

棉花苗期棉蚜的二项式抽样设计及其精度分析(英文)

1991年4月—7月在河北省北京农业大学曲周试验站的棉花地进行苗期棉蚜（Aphisgossypii）的田间抽样调查,共收集到24组抽样数据。用泰勒幂法则对数据进行拟合,得到棉花苗期棉蚜为聚集分布。利用每样方（株）虫口不超过数阈值T（分别为0,1,2…9,10,15,20,30）头蚜虫的植株比例（PT）与种群密度（m,头／株）的关系,拟合经验关系式ln（m）=a十bln[-ln（PT）],通过对不同数阈值T的回归决定系数（r2）、种群的回归估计方差（Var（m））和抽样精度（用d估计）等进行综合分析,结果表明该蚜虫在数阈值T为15时,回归估计方差最小,回归决定系数和d值最大,因而T=15为该蚜虫的理想数阈值;而小的T值尤其是T为O时,由于产生太大的回归估计方差,很小的回归决定系数和d值即抽样的精度极低,因而不宜在实际中应用于棉蚜的二项式抽样设计。     

Spatial distribution of the green peach aphid used in estimating the populations of gynoparae

Summary In 2 years, during the initial invasion of peach leaves by the green peach aphid,Myzus persicae (Sulzer), the number of gynoparae was low, and the distribution on leaves was random. Then as the mean number increased, the distribution became intermediate and could not be distinguished from either a Poisson or a negative binomial. Finally, as the mean continued to increase, the variance increased rapidly, and the population was found to fit a negative binomial distribution. Thus the aggregation response was verified because the dispersion pattern fitted a contagious distribution. A sampling plan was devised by which the dispersion parameterk was used to estimate the density of aphids per leaf based on the percentage of leaves infested. Sampling the third year of the study confirmed the validity of the sampling parameter that had been calculated from data for the 2 previous years.     

BINOMIAL COUNT ANALYSIS BASED ON THE SPATIAL DISTRIBUTION AND POPULATION DENSITY ESTIMATION OF COTTON APHIDS1)

Abstract  Based on field population sampling of Aphis gossypii on cotton seedlings in Quzhou Experiment Station of China Agricultural University in Hebei Province in 1991, we obtained a data set consisting of 24 estimates of mean aphid density ( m , number of aphids per plant), variance (s²) and the proportion of plants (P_T) with no more than T aphids (T=0, 1, 2,…, 8, 10, 15, 20, respectively and defined as tally threshold). Taylor's power law fitted the data well (r²= 0. 958). The resulting slope (1. 515) was significantly greater than 1, indicating that the spatial distribution of this aphid was in aggregated pattern. An empirical relationship between m and Pr was developed for each T value using the parameters from the linear regression In( m )= a +bln[- ln( P_T )}]. The importance of the T values in reduction of sampling errors and their application to binomial sampling plans are discussed. Small T values, particularly aphid-free plant (T = 0, conventional binomial sample), could lead to spurious estimates of m from P_T . A value of T from 10 to 15 was recommended to develop binomial sampling plans for the aphids on cotton seedlings because of the relatively small sampling errors.     

Modelling the dynamic spatio-temporal response of predators to transient prey patches in the field

The spatio-temporal dynamics of two aphid species ( Metopolophium dirhodum and Sitobion avenae ) and a generalist predator ( Pterostichus melanarius ) were observed in a field-scale study using a grid of 256 sampling locations with a 12-m spacing. Using Spatial Analysis by Distance Indices we demonstrate that populations show ephemeral spatial pattern at the field scale. We observed a positive, lagged beetle response to this aphid pattern; conversely, the aphids displayed a negative, lagged response to beetle spatial pattern. Examination of the local structure of the spatio-temporal dynamics revealed a strong response by the beetle population to aphid patches. The temporal structure of spatial associations between the species shows a strong correspondence with those from a conceptual model of predator–prey spatial interaction. The spatially coupled dynamics were sufficiently strong for the predator to have a negative effect on the intrinsic rate of increase of their prey.     

Cereal Aphid Colony Turnover and Persistence in Winter Wheat

An understanding of spatial and temporal processes in agricultural ecosystems provides a basis for rational decision-making with regards to the management and husbandry of crops, supporting the implementation of integrated farming strategies. In this study we investigated the spatial and temporal distribution of aphid pests (Sitobion avenae and Metopolophium dirhodum) within winter wheat fields. Using an intensive sampling programme we investigated distributions at both the small (single shoot) and large (field) scales. Within two fields, a grid with 82 locations was established (area 120 m by 168 m). At each location, 25 shoots were individually marked and aphid counts by observation conducted on 21 and 22 occasions as the crop matured, resulting in 43,050 and 45,100 counts being conducted in the two fields respectively. We quantified field scale spatial distributions, demonstrating that spatial pattern generally emerged, with temporal stability being both species- and field- dependent. We then measured turnover of colonies at the small (individual shoot) and large (field) scales by comparing consecutive pairs of sampling occasions. Four turnover categories were defined: Empty (no aphids recorded on either occasion); Colonised (aphids recorded on the second occasion but not the first); Extinction (aphids recorded on the first occasion but not the second); Stable (aphids recorded on both occasions). At the field scale, population stability soon established, but, at the small scale there was a consistently high proportion of unoccupied shoots with considerable colonisation and extinction and low stability. The redistribution of aphids within the crop at the local scale is a vulnerability which could be used to disrupt population development – by mediating exposure to ground-active natural enemies and by incurring a metabolic cost caused by the physiological demands to re-establish on a nearby host plant.     

Density-dependent dispersal may explain the mid-season crash in some aphid populations

Aphid population dynamics during the season show a characteristic pattern with rapid increase in numbers at the beginning followed by a sudden drop in the middle of the season. This pattern is usually associated with predation and/or change in food quality during the summer. By developing a mechanistic model of aphid population dynamics we show that this pattern can arise from density-dependent dispersal behaviour of aphids. The dynamics produced by the model were similar to those observed in real populations of the alder aphid (Pterocallis alni). The two mechanisms required for these oscillations to arise were the perception of density through the number of contacts with other individuals and the inter-generational transfer of information (the maternal effect). Both mechanisms are examples of delayed density-dependence and, therefore, this study adds to the evidence that delayed density-dependence might cause complex population dynamics. To reproduce the seasonal dynamics of the alder aphid with the model, the maternal effect was essential, indicating that this could be an important factor in alder aphid dynamics. According to our model, external regulations (e.g., predation and/or change in food quality) were not required to explain the highly oscillatory population dynamics of aphids during a season.     

Vertical and Temporal Distribution of Aphis gossypii Glover and Coccinellid Populations on Different Chilli (Capsicum annuum) Varieties

The vertical and temporal distribution of an aphid, Aphis gossypii Glover, and the coccinellid populations on six chilli varieties were studied. The total number of apterous aphid per plant stratum was significantly different among plant strata of a particular variety (treatment) as well as among the treatments. Generally, the total number of aphids was significantly greater in the lower stratum than in the middle and upper strata. However, the varieties with erect and open plant architecture (Kulai and MC 11) had significantly less number of apterous aphids at all strata as compared to varieties with compact or prostrate plant architectures. There was a significant difference in the total number of coccinellids per plant strata among the treatments but not within a treatment. The distribution of apterous aphid populations varied significantly among sampling periods and treatments. The temporal distribution of coccinellids showed a similar trend as that of apterous aphids. The total number of alate aphids caught per week was significantly different among the sampling periods. However, its population was significantly greater during the early season and gradually declined as the season progressed except during June 18 to 24. The importance of recording the most observed coccinellids species, which limit the aphid populations at each particular plant stratum per variety, and the conditions that favor natural enemies are also discussed.