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     

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．     

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。     

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。     

不同寄主植物与棉蚜酯酶活性的关系

通过测定不同越冬寄主植物棉蚜Aphis gossypii种群α-乙酸萘酯（α-NA）酯酶的活力,结果表明：山东高密棉田棉蚜种群酯酶活力是北京花椒棉蚜酯酶活力的2.4倍,石榴、木槿上棉蚜酯酶活力是花椒棉蚜酯酶活力的1.3-1.5倍,不同寄主植物棉蚜α-NA酯酶和β-NA酯酶的频率分布表明：鼠李、花椒棉蚜的α-NA酯酶频率分布范围较集中,酯酶活力（每0.033头蚜虫的OD值）小于0.10时的频率分别为70%和62%,其个体累积率达50%时的酯酶活性（EF50）分别为0.08和0.085(每0.033头蚜虫的OD值）;石榴、木槿和棉苗上α-NA酯酶频率分别为25%、31%和45%,其EF50分别的0.154、0.1368和0.1138,酯酶活力明显比鼠李和花椒棉蚜高;高密棉蚜为4%,EF50为0.2113,频率分布范围较宽。β-NA酯酶的频率分布,鼠李、花椒、木槿和棉苗上棉蚜酯酶活力（每0.033头蚜虫的OD值）小于0.10时为52%-62%的个体,EF50分别为0.098、0.084、0.102和0.091,寄主之间差异不大,而石榴和高密棉蚜分别为23%和3%,EF50分别为0.135和0.2136,与其它4个寄主有明显差异。     

棉花苗期棉株内含物与棉蚜种群消长动态及成蚜翅型分化的关系

棉蚜Aphis gossypii Glover是我省棉花苗期的主要害虫之一,其有翅型蚜虫的比例变动既是分析种群扩散趋势的一种指标,也是表示其环境(包括寄主营养)是否适宜的一个标     

不同类型品种棉花上棉蚜适生性及种群动态

通过田间调查、室内网罩盆栽苗测定选择性等方法,考察了常规棉（泗棉3号,石远321）、杂交抗虫棉（辽棉19号,鲁棉研18号）、转单价基因抗虫棉（国抗12号,中棉所32）和转双价抗虫棉（SGK321,中棉所41）4种类型8个品种棉花上棉蚜的适生性及种群动态。结果表明： 棉蚜在各棉花品种上的种群动态有明显差异（P<0.05）,单株蚜量以转单价基因抗虫棉中棉32上最高,常规棉泗棉3号上最低,分别为297.81头/株和76.88头/株。棉蚜对4种类型棉花品种的选择性有明显差异（P<0.05）,其中对转单价基因抗虫棉有很强的选择性。根据棉蚜实验种群的参数判断,其在不同品种棉花上的生长发育、存活及繁殖存在显著差异： 若虫发育历期常规棉石远321上最长（6.46天）,双价棉中棉所41上最短（5.75天）; 存活率转单价基因抗虫棉中棉32上最高（88.21%）,双价棉SGK321上最低（76.46%）; 单雌产蚜量杂交抗虫棉辽棉19上最大（44.48头）,双价棉SGK321上最小（33.51头）; 内禀增长率转单价基因抗虫棉中棉32上最高（0.3695）,双价棉中棉所41上最低（0.3389）。综合评价,棉蚜的生存和繁殖适合性在转单价基因抗虫棉上最高,在双价棉上最低。     

棉蚜在棉株上数量动态的初步研究

棉蚜(Aphis gossypii)是棉花苗期至花铃前期的主要害虫之一。长期以来,由于大量使用化学药物,其抗药性不断增加。为了掌握棉蚜种群数量消长的一般规律,给寻找其他有效的防治方法提供依据,本文对棉蚜实验种群的数量动态与其宿主棉株的关系进行了初步探讨。现将结果报道如下。     

田间中间寄主豇豆对专化型棉蚜的影响

中间寄主植物在植食性昆虫的取食选择和进化方向上起着重要的作用。本研究在田间设置罩笼,结合生态学调查和生物型鉴定技术研究了中间寄主豇豆对棉花型棉蚜和黄瓜型棉蚜专化性的影响。研究结果表明,棉花型棉蚜在豇豆上需经过1周时间的适应才能在豇豆上繁殖并在接虫后的第31天达到峰值(1 019±191头/百株),但不能够继续转移到黄瓜上建立种群;黄瓜型棉蚜在豇豆上在接虫后的第11天首次被记录后,其种群密度就迅速增加,到接虫后的第28天达到种群数量最大值(16 810±2 966头/百株),但也未能成功转移到棉花上存活并建立种群。在本实验研究条件下,中间寄主豇豆不能够改变棉花型棉蚜对棉花的偏好性,也不能在短期内改变黄瓜型棉蚜对黄瓜的专化性。     

不同温度条件对棉蚜、棉长管蚜种间竞争关系的影响

【目的】棉蚜Aphis gossypii和棉长管蚜Acyrthosiphon gossypii是棉花上的共存种,本文拟明确不同恒温条件下两种蚜虫单种和共存时的种群动态、有翅蚜发生及在棉株上的分布情况,探讨温度对两者种间竞争的作用。【方法】棉蚜、棉长管蚜单种、混合初始等蚜量设置,分别置于室内21、24和27℃恒温条件下,系统调查记录各处理种群数量、有翅蚜数量及在棉株上的分布,应用内禀增长率rm、空间分布情况、有翅蚜比例为竞争判别指标。【结果】棉蚜单种种群过程的rm均大于棉长管蚜,共存条件下一种对另一种蚜虫的rm均没有显著影响;棉蚜种群97%以上在叶片活动,棉长管蚜在叶片的比例为55%~75%;同一温度条件,两种共存不影响对方在棉花叶片和茎秆上的分布;棉蚜和棉长管蚜主要分布于棉花中上部。随温度升高,共存种群中棉蚜向棉株下部移动的比例增加,单种和共存种群棉长管蚜趋向于棉株上部移动。同一温度条件下,共存对棉蚜上下分布没有明显影响。21℃和27℃棉蚜的存在对棉长管蚜没有显著影响,但24℃时共存可使棉长管蚜在下部的比例明显增加;随温度的升高,棉蚜有翅蚜比例下降显著,而棉长管蚜无显著变化。【结论】适温范围内,两种蚜虫种间竞争的存在不影响彼此的内在繁殖能力,棉蚜比棉长管蚜具有更强的内在竞争能力;温度对棉蚜在竞争活动空间上的影响不明显,而对棉长管蚜的上下位置的选择有一定作用;种间竞争和种内竞争加速棉蚜有翅蚜的发生。     

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.     

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.     

Enumerative and binomial sequential sampling plans for soybean aphid (Homoptera: Aphididae) in soybean

Since the discovery of the soybean aphid, Aphis glycines Matsumura, in midwestern U.S. soybean, Glycine max L., in 2000, the aphid has become a significant economic pest. Basic information about estimating population density within fields is unknown. Therefore, we developed two sampling plans to efficiently characterize A. glycines densities. Enumerative and binomial sequential plans were developed using 89 data sets collected from 10 commercial fields sampled during 2001-2003. Re-sampling software was used to validate the enumerative plan on whole plant counts, based on Taylor's power law parameters (a = 9.157 and b = 1.543). For research applications, the enumerative plan was modified to provide an actual precision level of 0.10 (SE/mean), which resulted in an average sample number of 310 individual plants. For integrated pest management (IPM) purposes, we developed an enumerative plan with an actual precision of 0.25, which resulted in an average sample number of 38 individual plants. For IPM applications, the binomial plan will likely be more practical. Binomial plans were developed using two tally thresholds at five action thresholds. Final analysis of the operating characteristic curve for each plan indicated that the tally threshold of > or = 40 aphids per plant, and an action threshold of 0.837 (84% of the plants infested) provided the most correct treat (4%) and no-treat (95%) decisions, with very low incorrect treat (0.5%) and no-treat (0.5%) decisions. A tally threshold of > or = 40 aphids per plant and action thresholds of 84% of plants infested is equivalent to a mean density of 250 aphids per plant, a recently recommended economic threshold. Using this threshold, the minimum required sample number for the binomial plan was 11 plants.     

嵊泗列岛潮间带群落生态学研究Ⅱ.岩相潮间带底栖动物的群落结构

用Shannon-Wiever多样性指数、Pielous种类均匀度、Margalef种类丰度、McNaushton优势度4个测定群落种类多样性指标进行数值分析.结果表明,嵊泗列岛从近岸到外海.H'(S)、J、d值呈现逐渐增加的趋势.而D值则有逐渐减小的趋势;各断面多样性指数H'(S)以春、秋季较高,J值则基本上以春、冬季稍高,d值则随断面的不同有差异,D值基本上以夏、秋季为高用Whiftaker和Fairbanks群落系数计算公式及Bray-Curtis群落相似性指数进行群落相似性及聚类分析,结果表明,嵊泗列岛潮间带底栖动物群落结构可聚为两大类型,从结构上看.近外海底栖动物群落为近岸及外海群落的过渡类型.     

Sequential decision plans for the management of cotton arthropods in south-east Queensland

An outline of a pest management plan for cotton insects has been developed that is essentially based on three sets of sequential sampling plans. These plans utilize the binomial sampling theory and treatment levels for pests during three phenological stages of cotton plant growth. The plans also provide a known level of accuracy in making management decisions and frequently will require less time than other sampling techniques.     

Operating characteristics of full count and binomial sampling plans for green peach aphid (Hemiptera: Aphididae) in potato

Counts of green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), in potato, Solanum tuberosum L., fields were used to evaluate the performance of the sampling plan from a pest management company. The counts were further used to develop a binomial sampling method, and both full count and binomial plans were evaluated using operating characteristic curves. Taylor's power law provided a good fit of the data (r2 = 0.95), with the relationship between the variance (s2) and mean (m) as ln(s2) = 1.81(+/- 0.02) + 1.55(+/- 0.01) ln(m). A binomial sampling method was developed using the empirical model ln(m) = c + dln(-ln(1 - P(T))), to which the data fit well for tally numbers (T) of 0, 1, 3, 5, 7, and 10. Although T = 3 was considered the most reasonable given its operating characteristics and presumed ease of classification above or below critical densities (i.e., action thresholds) of one and 10 M. persicae per leaf, the full count method is shown to be superior. The mean number of sample sites per field visit by the pest management company was 42 +/- 19, with more than one-half (54%) of the field visits involving sampling 31-50 sample sites, which was acceptable in the context of operating characteristic curves for a critical density of 10 M. persicae per leaf. Based on operating characteristics, actual sample sizes used by the pest management company can be reduced by at least 50%, on average, for a critical density of 10 M. persicae per leaf. For a critical density of one M. persicae per leaf used to avert the spread of potato leaf roll virus, sample sizes from 50 to 100 were considered more suitable.     

Effect of cotton cultivar on performance of Aphis gossypii (Homoptera: Aphididae) in Iran

Cotton aphids, Aphis gossypii Glover (Homoptera: Aphididae), obtained from cotton, Gossypium hirsutum L., fields in the Gorgan region of northern Iran, were colonized on 'Varamin' cotton plants in a growth chamber. The development, survivorship, and life table parameters of the cotton aphid were evaluated at 27.5 +/- 1 degrees C, 65 +/- 10% RH, and aphotoperiod of 14:10 (L:D) h of artificial light on five commonly growing cotton cultivars: Varamin, 'Sealand' (relatively resistant cultivar), 'Bakhtegan', 'Sahel' (both relatively susceptible cultivars), and 'Siokra' [resistant to Bemisia tabaci (Gennadius)]. The developmental times of immature stages ranged from 4.6 d on Bakhtegan and Varamin to 6.3 d on Sealand, whereas the immature survival was 97.5 to 65% on Sahel and Siokra, respectively. On average, there were 28.7, 28.3, 23.5, 20.1, and 16.8 nymphs produced per female on Sahel, Bakhtegan, Varamin, Sealand, and Siokra, respectively. The intrinsic rate of natural increase (r(m)) for cotton aphids on Sahel was the highest, whereas the values for r(m) varied from 0.284 (nymphs per female per d) on Siokra to 0.368 on Sahel. Jackknife estimates of generation times (T), net reproductive rate (R(0)), doubling time (DT), and finite rate of increase (lambda) on these cultivars were as follows: 9.79-10.84 d for T, 9.23-23.81 nymphs per female for R(0), 2.17-3.19 d for DT, and 1.28-1.38 nymphs per female per d for lambda. Cotton aphid performance was at its highest on Sahel and lowest on Siokra.     

Binomial sampling as a cost efficient sampling method for pest management of cabbage root fly (Dipt., Anthomyiidae) in cauliflower

A binomial (presence–absence) sampling plan has been developed based on the relationship between the proportion of cauliflower plants having visible cabbage root fly eggs ( Delia radicum L.) exposed on the soil surface around the plant stem and the mean density of eggs per plant. The Kono–Sugino's model was fitted to a total of 125 population estimates, each based on 10 plant samples collected from cauliflower fields in 1994 and 1995 (P=0.001; R²=0.64). When the model was compared with an independent data set consisting of 39 population estimates collected in 1995, an analysis of covariance showed no significant differences between the regression lines. The efficiency of the binomial method was compared with absolute sampling in terms of relative precision and cost efficiency. The binomial method had a high coefficient of variation, RV ≈ 0.85, due to large biological error. In spite of this, binomial sampling was more cost efficient than the applied soil sampling when between 10 and 30 plants were examined for the presence of visible eggs.