麦长管蚜的序贯二项式分类抽样设计与管理决策优化：样本单位虫口数阈的重要性

依据１９８８～１９９１年间对麦长管蚜（Ｓｉｔｏｂｉｏｎａｖｅｎａｅ）种群的抽样数据和新的抽样理论而设计了用样本单位（分蘖株）虫口数阈Ｔ（每株不超过Ｔ头蚜虫,Ｔ≥０）进行样本分类的序贯二项式分类抽样方案,用于蚜害的管理决策。负载不超过Ｔ头蚜虫的植株比例（ＰＴ）与种群密度（ｍ,头／株）的关系通过拟合经验式ｌｎ［－ｌｎ（ＰＴ）］＝ａ＋ｂｌｎ（ｍ）和负二项分布的概率模型而建立。一系列Ｔ值（０～２５）和３个干扰阈限即经济危害水平（２．５和１０头／株）用于抽样方案的设计和比较,以优化麦作不同生育期控制蚜害的决定。抽样设计的可靠程度和经济性状分别由运行特征（ＯＣ）函数和平均样本数（ＡＳＮ）函数判别。结果显示,各干扰阈限的抽样设计随Ｔ值的增大而愈趋合理。传统的０－ｌ抽样（Ｔ＝０）被证明错误决策的风险很大,所需样本数最多,应当摒弃。考虑到Ｔ过大会增加处理单位样本的时间,作者建议使用略高于干扰阈限的Ｔ值进行麦蚜的分类抽样和田间管理决策。     

萝卜蚜不同虫口密度下的二项式抽样设计

基于1990—1992年间对杭州市郊区小白菜上萝卜蚜（Lipaphiserysimi）种群的田间抽样调查数据,根据虫口密度（m）,将数据归为两组,一组为整个虫口密度范围的数据;另一组为虫口密度≤5头／株范围的数据．每组数据选择不同的数阈值（T）,利用每样方不超过T头蚜虫的植株比例（P_T）与种群密度的关系,通过拟合经验公式Ln进行二项式抽样设计．对抽样方差（用MSE估计）、抽样精度（用d估计）进行分析发现,当用整个密度范围的数据进行拟合,且种群处于较高密度（m≥5）时,其理想的T值为10,可用于小白菜上萝卜蚜种群的二项式抽样设计．当用虫口密度m≤5的数据进行拟合时,T＝4时可保证抽样精度,但从实际应用考虑,则不宜用于萝卜蚜的二项式抽样设计．应用本文方法所发展的0—1抽样方法,无论是在整个密度范围还是在密度≤5的范围,都由于产生较大的抽样误差而不宜用于萝卜蚜。     

棉花苗期棉蚜的二项式抽样设计及其精度分析

基于棉花苗期棉蚜（Ａｐｈｉｓ ｇｏｓｓｙｐｉｉ）的２４组调查数据,利用每样方虫口不超过数阈值Ｔ（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１ｎ（ｍ）＝α＋ｂ１ｎ〔－１ｎ（ＰＴ）〕设计二项式抽样。通过对不同数阈值Ｔ的决定系数（ｒ＾２）、估计方差（Ｖａｒ（ｍ））和抽样精度（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     

田间不同品种蔬菜对萝卜蚜种群的影响(英文)

本试验通过利用５个品种蔬菜（萝卜,芥蓝,芥菜,菜芯和白菜）研究萝卜蚜（Ｌｉｐａｐｈｉｓ ｅｒｙｓｉｍｉ）在不同蔬菜上的种群动态以及对寄生于萝卜蚜的菜蚜茧蜂（Ｄｉａｅｒｅｔｉｅｌｌａ　ｒａｐａｅ）种群的影响。研究结果显示,在３０天研究期间,有翅萝卜蚜的平均虫口（蚜虫数／苗）在萝卜、芥蓝、芥菜、菜芯和白菜苗上分别为３．９１８、０．８３１、１．１４９、１．７４３和５．２３头,表明降落在萝卜苗上的有翅蚜数量显著地比在其它蔬菜苗上的高;而无翅萝卜蚜的中均虫口分别为６３．４２１、１０．０４１、２４．９２８、２３．３２３和１１４．３０８头,说明萝卜蚜无翅蚜在白菜上的种群显著地高于其它品种蔬菜上的。由于萝卜蚜在不同品种蔬菜上的种群不同,导致菜蚜茧峰种群在不同品种蔬菜上也不同,其僵蚜虫口分别为１．０５６、０．２５１、０．２７７、０．６５１和１．４４头,显示了在萝卜和白菜上的僵蚜数量显著地比其它蔬菜上的高。分析结果表明,萝卜蚜的种群（ｘ）与菜蚜茧峰的种群（ｙ）呈显著的相关关系：ｙ＝０．１１８８＋０．０１４３ｘ（ｒ＝０．９７３９）。本研究还利用试验结果提出了萝卜蚜无翅蚜种群从蔬菜在田间种植后达到防治指标（５０头／苗）的临界天数（ｃ     

不同温湿度组合对安微虫瘟霉诱发桃蚜病害的影响

用孢子浴方法,对４２批次桃蚜Ｍｙｚｕｓ ｐｅｒｓｉｃａｅ（３０－６０头／批）接种大剂量（孢子７９－９０个／ｍｍ＾２）安徽虫瘟霉Ｚｏｏｐｈｔｈｏｒａ ａｍｈｕｉｅｎｓｉｓ的分生孢子,在２０℃下保湿２４ｈ后转入不同温度（１０℃、１５℃、２０℃、２５℃、３０℃及自然变温下１．５－１６．６℃和８．５－２０．２℃）和温度（５０％、６５％、８０％、９０％９５％及１００％ＲＨ）的组合条件下观察桃蚜的反应。结果表     

桃蚜、萝卜蚜的种内密度和种间竞争效应

在温室内不同密度条件下,研究了桃蚜和萝卜蚜在甘蓝上的种内密度效应和种间竞争作用。结果表明：单独饲养时,在5头／株和10头／株密度下,两种蚜虫种内密度效应均较弱;而在15头／株时,桃蚜和萝卜蚜的寿命和产蚜量都随之显降低,说明当两种蚜虫达到一定的拥挤程度时,种内密度对种群均产生一定的负效应。两种蚜虫共存时,单头产蚜量均比单独饲养时显下降,种问竞争作用明显。在10、15头／株密度下,桃蚜的竞争作用大于萝卜蚜,萝卜蚜的寿命和单头产蚜量都极显低于桃蚜。     

大草蛉对桃蚜和夹竹桃蚜的捕食作用研究

大草蛉在我国分布广泛，能捕食多种农作物害虫。本试验首先研究了大草蛉一龄幼虫对桃蚜、大草蛉二龄幼虫对桃蚜和夹竹桃蚜的捕食功能反应。三个反应的最大捕食量Namax分别为144．93、303．03和151．51（头），瞬时攻击率a分别为0．7428、0．8654和0．6644。大草蛉一龄幼虫有较强的种内干扰反应，随着捕食者密度的增加，捕食作用率（E）依次为0．2025、0．1185、0．0866、0．0694和0．0584；对桃蚜的捕食作用率（E）与自身密度（P）的函数关系式为E=0．2025P^-0.7727。在桃蚜和夹竹桃蚜的混合种群中，大草蛉二龄幼虫对桃蚜的选择效应大于夹竹桃蚜。     

三突花蛛对桃蚜和桃粉蚜选择效应研究

三突花蛛是桃树上早春2种重要害虫桃蚜和桃粉蚜的主要天敌。对这2种害虫的捕食喜欢程度,受害虫种群密度的变化而变化。在二者等密度增加时,其捕食喜好程度相近;在桃蚜数量明显增加时,喜食桃蚜;在桃蚜数量剧增时,当两者密度值在50:50以下,喜食桃蚜,高于此值,则喜食桃粉蚜。     

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。     

角圆尾蚜属研究及一新种记述（同翅目：蚜科）

本文系统研究了角圆尾蚜属ＣｅｒｕｒａｐｈｉｓＢｏｒｎｅｒ, １９２６, 并描述了１新种：食沙棘角圆尾蚜ＣｅｒｕｒａｐｈｉｓｈｉｐｐｏｐｈａｅｔｒｏｐｈｉｓＺｈａｎｇ, ｓｐ． ｎｏｖ．,给出了该属所有种类的分种检索表。新种与Ｃ． ｅａｓｔｏｐｉ近似,但尾片有毛９～１２根（后者５根）,触角末节端部约等于基部（后者４倍）。新种的模式标本存放于中国科学院动物研究所昆虫标本馆。食沙棘角圆尾蚜ＣｅｒｕｒａｐｈｉｓｈｉｐｐｏｐｈａｅｔｒｏｐｈｉｓＺｈａｎｇ, 新种（图１）有翅孤雌蚜：活时体绿色,体长１．１７０、体宽０．４２０ｍ ｍ 。玻片标本头、胸黑色,触角、足和尾片灰色。额具中额瘤,额瘤不存在。触角５节,长０．７６０ｍ ｍ ,为体长的０．６５;节Ⅰ～Ⅴ比例：１３,１３,１００,４２,３５＋ ３５。触角次生感觉圈小圆形,节Ⅲ～Ⅵ分别有１６～２０,１～３个。腹管端部直径大于基部直径。雌性蚜：活时体绿色,体长１．５９０、体宽０．７４０ｍ ｍ 。额具中额瘤,额瘤不存在。头顶缘毛相当长,约为触角节Ⅲ直径的４．００～５．００倍。复眼无眼瘤。触角５节,长０．５８０ｍ ｍ ,为体长的０．３７;触角节Ⅰ～Ⅴ长度比例：２６,１８,１００,５８,５８＋     

Ranked set sampling for replicated sampling designs

In practical ecological sampling studies, a certain design (such as plot sampling or line-intercept sampling) is usually replicated more than once. For each replication, the Horvitz-Thompson estimation of the objective parameter is considered. Finally, an overall estimator is achieved by averaging the single Horvitz-Thompson estimators. Because the design replications are drawn independently and under the same conditions, the overall estimator is simply the sample mean of the Horvitz-Thompson estimators under simple random sampling. This procedure may be wisely improved by using ranked set sampling. Hence, we propose the replicated protocol under ranked set sampling, which gives rise to a more accurate estimation than the replicated protocol under simple random sampling.     

Comparison of Cytobrush sampling, spatula sampling and combined Cytobrush-spatula sampling of the uterine cervix

Since the introduction of the Cytobrush for sampling the uterine cervix, some practitioners have ceased taking a concomitant cervical scraping using a spatula. To examine whether Cytobrush sampling alone is adequate for the diagnosis of cervical lesions, the Cytobrush and spatula samples in 444 smears (most with original diagnoses of at least mild dysplasia) were analyzed separately for the presence of diagnostic cells, endocervical cells and squamous cells. Of the 412 smears showing pathologic findings (mild to severe dysplasia or worse), diagnostic cells were present in 400 Cytobrush samples and in 369 spatula samples; the combination of both samples thus gave a 3% gain in correct diagnoses as compared to use of the Cytobrush samples alone. Another 18 smears would have been underdiagnosed based only on the Cytobrush samples. Endocervical cells were present in 95.3% of the Cytobrush samples and 83.8% of the spatula samples; squamous cells were present in 93.9% of the Cytobrush samples and 96.8% of the spatula samples. Analysis confirmed that it is important that the smear should contain both endocervical and squamous cells. A positive relationship between the absence of squamous cells in the Cytobrush sample and the probability of a false-negative assessment was suggested. It thus seems inadvisable to replace the combination sampling method by Cytobrush sampling alone, which may lead to a false-negative diagnosis.     

Adaptive web sampling

A flexible class of adaptive sampling designs is introduced for sampling in network and spatial settings. In the designs, selections are made sequentially with a mixture distribution based on an active set that changes as the sampling progresses, using network or spatial relationships as well as sample values. The new designs have certain advantages compared with previously existing adaptive and link-tracing designs, including control over sample sizes and of the proportion of effort allocated to adaptive selections. Efficient inference involves averaging over sample paths consistent with the minimal sufficient statistic. A Markov chain resampling method makes the inference computationally feasible. The designs are evaluated in network and spatial settings using two empirical populations: a hidden human population at high risk for HIV/AIDS and an unevenly distributed bird population.     

Repeated sampling but not sampling hour affects plasma carotenoid levels

Carotenoid pigments have become a central subject of research on animal signaling systems during the past decade. Thus, measurement of plasma carotenoid levels is widespread in the literature. Many plasma biochemical parameters tend to vary with the hour of sampling, which may be an important source of sampling error. However, little is known about this kind of variation for circulating carotenoids. With a sampling protocol that allowed us to separately analyze the effect of sampling hour and repeated blood extraction at the within-individual level, we evaluated the effect of these two parameters on plasma carotenoid concentration in captive red-legged partridges (Alectoris rufa). The hour of sampling did not show a significant influence on carotenoid variability. Nevertheless, carotenoid levels significantly decreased as a result of repeated sampling. In fact, carotenoid variability was positively related to hematocrit values, which also decreased throughout the experiment. Furthermore, the effect was evident from the second sampling event. These results suggest that blood samples for carotenoid analysis may be obtained at random during the daytime with no serious risk of adding variance to data obtained. However, the effect of hemodilution associated with repeated blood extraction should be carefully considered in those studies involving repeated sampling.     

Accounting for cluster sampling in constructing enumerative sequential sampling plans

Green's sequential sampling plan is widely used in applied entomology. Green's equation can be used to construct sampling stop charts, and a crop can then be surveyed using a simple random sampling (SRS) approach. In practice, however, crops are rarely surveyed according to SRS. Rather, some type of hierarchical design is usually used, such as cluster sampling, where sampling units form distinct groups. This article explains how to make adjustments to sampling plans that intend to use cluster sampling, a commonly used hierarchical design, rather than SRS. The methodologies are illustrated using diamondback moth, Plutella xylostella (L.), a pest of Brassica crops, as an example.     

Photographic sampling: a photographic sampling method for mites on plants

A photographic sampling method for mites on plants was evaluated using Tetranychus urticae and Phytoseiulus persimilis on pepper plants. It was found to be 92% accurate for T. urticae eggs and 98% accurate for P. persimilis eggs at densities up to 45 eggs per cm² for T. urticae, and up to 3 eggs per cm² for P. persimilis. The motiles of the two species were not confused, nor were they confused with exuviae or other matter.     

Microdialysis sampling of cytokines

Microdialysis sampling is a well-known method for collection of low molecular weight hydrophilic analytes. Due to the success of this sampling technique for these analytes, many researchers have wanted to extend the use of this method to a wider range of analytes-particularly proteins and peptides. These analytes pose unique challenges during microdialysis sampling. The primary challenges are the reduced recovery across the dialysis semi-permeable membrane and the volume limitations/requirements for the typical immunoassay methods used for detection of proteins. This review covers the practical and theoretical aspects needed for in vivo microdialysis sampling of cytokines, which are a vitally important class of signaling proteins. In addition to the basics of the microdialysis method for sampling cytokines, the use of the microdialysis device as a localized cytokine delivery method is also described. Since relative recovery of cytokines is often low during microdialysis sampling, methods to improve the membrane recovery are discussed for in vitro and in vivo applications.