二点叶蝉自然种群的时空动态

选择受密度影响较小的负二项分布K值 ,描述玉米上二点叶蝉自然种群在 3个海拔高度上的空间格局及时序动态。在玉米生育期间 ,二点叶蝉种群即可作聚集分布亦可作均匀分布。 4月中下旬 ,二点叶蝉种群呈均匀分布 (K <0 ) ;5月份 ,呈聚集分布 (K >0 ) ;6月上中旬呈均匀分布 (K <0 ) ;6月下旬至 7月上旬呈聚集分布 (K >0 ) ,表现为扩散→聚集→再扩散→再聚集的总趋势。K值亦表明 ,5月份高海拔聚集强度最高 ,6月下旬至 7月上旬则低海拔的聚集强度最高。根据Taylor的幂函数法和Iwao的M -X回归方程的系数 ,高、中海拔的聚集强度大于低海拔     

新疆葡萄斑叶蝉若虫的发育起点温度和有效积温

室内饲养观察表明 ,5月 1日从吐鲁番地区田间采集的葡萄斑叶蝉ZyginaapicalisNawa越冬代成虫存活时间长 ,室内饲养仍然可存活 45d以上 ;在适宜温度下 ,单雌繁殖后代 5 0～ 60头 ;在 1 9～ 3 1℃ 5个温度处理中 ,若虫发育历期在 1 2 6～ 2 1 1d之间 ;2 2～ 2 8℃是发育的适温范围 ,以 2 8℃为最佳发育温度。若虫发育起点温度为 5 2 ,有效积温为 3 0 7 1日·度。     

基于地统计学和GIS的苜蓿斑蚜种群空间结构分析和分布模拟

运用地理信息系统(GIS)和地统计学方法对宁夏南部固原市原州区不同时期苜蓿斑蚜(Therioaphis trifolii)种群的空间结构进行了分析,并采用普通克立格插值法模拟了苜蓿斑蚜种群空间分布.结果表明:不同时期苜蓿斑蚜种群存在空间相关性,其半变异函数曲线均为指数型,空间格局呈聚集分布,空间变异成分的变化范围为34.13%~48.77%,空间相关范围为8.751~12.049km,聚集程度和方向有从西南向东北方向聚集的趋势.空间分布模拟图能较好地从时间、空间两个角度直观地分析不同时期苜蓿斑蚜种群的动态变化,易于确定同一时期苜蓿斑蚜的发生位置和发生程度.     

基于地统计学的新疆棉田烟粉虱(Bemisia tabaci (Gennadius))危害动态与时空分布

应用地统计学(GS)的原理与方法研究了外来入侵有害生物烟粉虱(Bemisia tabaci (Gennadius))为害新疆棉田的时空动态,并与经典统计学进行对比分析.两种方法一致表明,烟粉虱成虫在空间上呈聚集分布的格局,而各时期成虫的聚集程度依据空间变异随机程度所占的比例不同而不同.经频次分布检验,以零频率法参数拟合的负二项分布来表达其空间分布型最为合适.运用GS的分析方法,进一步得到种群分布面积变化与扩散的趋势,并依此对昆虫种群的扩散模型进行模拟.棉田烟粉虱成虫在田间7～8月份均存在一定的空间相关性,随机程度为19.22%～49.99%;空间相关距离(相关程)在一个月内从32m急速增至6372m,随后在2000～3000m的范围波动.从整个发生过程看出,烟粉虱从越冬场所顺风侵入大田后,迁飞扩散在很大程度上受风向的影响,属于典型的借助风力扩散的昆虫,其在棉田的垂直分布则与吐鲁番地区独特的暖温带大陆性干旱荒漠气候特征有关.顺风扩散时多从棉株上部叶片开始危害, 而逆风扩散时从棉株中、下部叶片危害.烟粉虱在棉株上建立稳定种群后,中、下部虫口密度要略高于上部, 这是烟粉虱对吐鲁番地区特殊气候的适应.     

柰树桃一点叶蝉的研究

柰树桃一点叶蝉Brythroneura sudra (Distant)在福建古田一年发生六代,7—9月温度较高,发生育较快,时虫口密度大,产卵量多,是主要的危害世代,本文对桃一点叶蝉的生活史与习性、繁殖特征（性比、产卵量）、1—4代的世代历期,发育起点与有效积温、种群空间分布型进行研究。同时进行了氧化乐果防治实验。     

桃一点斑叶蝉种群消长动态和空间分布型研究

研究探明了桃一点斑叶蝉Erythroneurasudra种群消长动态和空间分布型 ,结果表明 :该虫在桃园全年共出现 3个为害高峰 ,分别发生于 4月下旬、5月下旬和 8月上旬 ;该害虫在桃园中呈聚集型的负二项分布。讨论了适宜取样调查方法。     

桃一点叶蝉及草间小黑蛛空间格局的地学统计学研究

应用地学统计学的原理和方法方法研究了不同时期桃－点叶蝉及草间小黑蛛种群的空间结构和空间相关性。结果表明,不同时期桃－点叶蝉种群的半变异函数曲线皆为球型,其空间格局为聚集型,变程在25.71-37.14m之间,草间小黑蛛种群的拟合并变异函数也表现为球型,呈聚集空间格局,空间变程在25.12-44.06m之间,并与桃－点叶蝉种群在数量和空间上有较强的追随关系,说明草间小黑蛛种群是桃一点叶蝉种群的优势种天敌。     

树桃─点叶蝉的研究

树桃—点叶蝉Ｅｒｙｔｈｒｏｎｅｕｒａｓｕｄｒａ（Ｄｉｓｔａｎｔ）在福建古田一年发生六代,７—９月温度较高,发育较快,时虫口密度大,产卵量多,是主要的危害世代。本文对桃一点叶蝉的生活史与习性、繁殖特征（性比、产卵量）、１—４代的世代历期、发育起点与有效积温、种群空间分布型进行研究。同时进行了氢化乐果防治实验。     

珍稀濒危植物桫椤种群结构与动态研究

采用空间序列代替时间变化的方法,对7个地段中的桫椤种群大小结构进行分析,运用C、K、m^*、m^*/m和Iδ5种聚集度指标测定不同地段内桫椤种群的空间分布格局及其动态,并根据植株个体点位图,考察桫椤种群在不同取样尺度上的空间分布格局.结果表明,不同地段中的桫椤种群结构存在增长型、稳定型、成熟型和衰退型4种类型;不同地段中的桫椤种群空间分布格局有所差异,表现为集群分布或随机分布;在桫椤种群生长过程中,分布格局从集群型向随机型转变;种群扩散型指数Iδ随取样尺度的增大而减小.     

海南岛黎母山四眼斑水龟种群密度与空间分布格局

2004年3～7月,采用系统抽样法在海南岛黎母山对四眼斑水龟（Sacalia quadriocellata）种群密度与空间分布进行了调查,采用Cassie指数、David＆Moore指数、Morisita指数和Lloyd指数测定了四眼斑水龟种群空间分布格局。结果表明,（1）四眼斑水龟种群分布于海拔170～470m范围内,在垂直梯度上呈现不连续的分布状态;（2）在海拔170～470m范围内种群相对密度为0．011～0．050只／笼捕日;（3）种群空间分布呈现聚集分布格局;（4）资源的空间分布特点和人为干扰可能对四眼斑水龟种群密度及空间分布格局有重要影响。     

绿僵菌药后草原蝗虫种群空间分布型研究

综合多个聚集度指标对绿僵菌药后田间蝗虫和僵虫的空间分布型进行了研究。结果表明：施药后不同时间随蝗虫种群密度的减小,处理区残虫的分布型呈现聚集随机交错变动,僵虫的空间分布型为聚集分布。采用Taylor幂法则和改进的Iwao模型分析表明,整个调查时段处理区残虫、僵虫的空间分布均为聚集分布。推测认为,药后蝗虫点片状死亡,部分地片相对密度较高,残虫分布型趋向聚集; 自然消除作用使僵虫密度很低,低密度下取样产生大量空样本,僵虫的分布型产生聚集假象。     

Dispersion models and sampling of cacao mirid bug Sahlbergella singularis (Hemiptera: Miridae) on Theobroma Cacao in southern Cameroon

The spatio-temporal distribution of Sahlbergella singularis Haglung, a major pest of cacao trees (Theobroma cacao) (Malvaceae), was studied for 2 yr in traditional cacao forest gardens in the humid forest area of southern Cameroon. The first objective was to analyze the dispersion of this insect on cacao trees. The second objective was to develop sampling plans based on fixed levels of precision for estimating S. singularis populations. The following models were used to analyze the data: Taylor's power law, Iwao's patchiness regression, the Nachman model, and the negative binomial distribution. Our results document that Taylor's power law was a better fit for the data than the Iwao and Nachman models. Taylor's b and Iwao's β were both significantly >1, indicating that S. singularis aggregated on specific trees. This result was further supported by the calculated common k of 1.75444. Iwao's α was significantly <0, indicating that the basic distribution component of S. singularis was the individual insect. Comparison of negative binomial (NBD) and Nachman models indicated that the NBD model was appropriate for studying S. singularis distribution. Optimal sample sizes for fixed precision levels of 0.10, 0.15, and 0.25 were estimated with Taylor's regression coefficients. Required sample sizes increased dramatically with increasing levels of precision. This is the first study on S. singularis dispersion in cacao plantations. Sampling plans, presented here, should be a tool for research on population dynamics and pest management decisions of mirid bugs on cacao.     

关于Taylor幂法则的统计学讨论

自Greenwood于1920年把负二项分布引做昆虫种群空间格局模型以来,昆虫种群空间格局分析的理论和方法大致经历了两个阶段的发展:五、六十年代以前,是以少数离散型概率分布为主要模型;其后,各种聚集性指标和一些回归公式被提出,显示了比原有     

桔小实蝇自然种群蛹和越冬成虫的耐寒性

本文通过过冷却点和低温耐寒能力的测定,研究了我国桔小实蝇Boctrocera dorsalis (Hendel)不同季节种群和地理种群蛹的耐寒性规律。结果表明：桔小实蝇自然种群蛹的低温存活力有明显的季节规律,冬前种群的耐寒性显著强于夏季种群。如在0℃低温下暴露2天,夏季种群基本全部死亡,而冬前种群存活率仍为61.4%。2005-2006年不同月份桔小实蝇1日龄蛹过冷却点差异明显,以2月份均值最高,为-9.26℃,8月份最低,为-15.20℃;且2月份桔小实蝇蛹个体过冷却点值出现明显的分化现象,分别在-15℃左右和-6℃左右出现两个明显的聚集区。所研究的5个桔小实蝇地理区域种群没有出现明显的耐寒性分化。结合本文结果,文中还就桔小实蝇自然种群耐寒性影响因素进行了讨论。     

Population Differentiation in Locomotor Performance and the Potential Response of a Terrestrial Organism to Global Environmental Change

SYNOPSIS. Models of global climate change predict an increasein the mean surface temperature between 1.5° and 4.5°Cby the middle of the next century. Even a moderate increaseof 3°C is likely to result in a shift in the distributionof North American habitat types and vegetational associations,either in latitude or elevation or both. The challenge to ConservationBiology is to predict the responses of terrestrial organismsto the expected alteration in habitats and ecosystems. Recentbiophysical models have been expanded to demonstrate the intimateassociations between the thermal environment, organismal physiologyand ecology. Thus, the expected turnover in habitats may havea profound influence on the distribution of organisms. I describeone possible approach that couples temporal and spatial variationin an ecologically relevant physiological trait, locomotoryperformance, in a widespread species of lizard, Urosaurus ornatus,to predict the expected response of species to global change. Estimates of maximum velocity and endurance capacity were obtainedfrom 16 populations throughout the range of U. ornatus. Informationon spatial variation was supplemented with data on temporalvariation spanning an eight year period from a single referencepopulation. I used thesedata to address two questions: 1) isthere an association between locomotory performance and theexpected habitat changes predicted from global climate modelsand 2) is there sufficient variation within a population torespond to habitat modification. Populations of U. ornatus varied significantly in sprint speedand stamina. Several environmental factors expected to correlatewith global climatechange were evaluated using the patternsof variation in locomotor performance. Results from this studysuggest that high elevation populations found in ponderosa pineforests should be most susceptible to changes in climate. Within-populationvariation was found to span the range of variation seen amongpopulations and was sensitive to temporal variation in climaticconditions. Given the expected and rapid change in environments,small, ectothermic, terrestrial species may not have the abilityto modify their geographic distribution. However, the resultspresented here suggest that only certain populations are atrisk; yet the evolutionary response of the population may belong relative to the rate of environment change.     

柳厚壁叶蜂幼虫空间格局及抽样技术

应用Taylor的幂法则、Iwao m^*-m回归分析法及6个聚集指标,对柳厚壁叶蜂幼虫空间分布型进行了研究,并进行了影响因素分析.结果表明,该幼虫在柳树的枝条和叶片两个空间阶元都属于聚集分布,分布的基本成分是个体群,其聚集性随密度的增大而增加.在枝条上,聚集的原因是由柳厚壁叶蜂成虫集中产卵的习性与枝条上叶片空间位点共同影响所致;在叶片上,当m＜2.37时,其聚集原因与春季柳树新叶空间位置有关,当m＞2.37时,虫瘿聚集除与春季新叶空间位置有关外,还与柳厚壁叶蜂成虫羽化和在叶片上集中产卵的习性有关.运用Iwao m^*-m回归中的两个参数α和β值,确定了在不同精度下的理论抽样数及序贯抽样数.     

紫薇毡蚧种群生物学特性研究

该文报道紫薇毡蚧EriococcusLagerostroemiae Kuwana的种群生物学特性。该虫80年末传入贵州,在贵阳地区每年发生3-4代,世代重叠极重,越冬代是第3、4两代的混合群体,越冬虫态有卵、若虫和蛹。分别估测了卵、雄若虫、蛹、雌若虫和雌成虫的发育起点温度(T₀)和有效积温(K)。周年虫口变动有两个高峰：6月中旬至7月上旬和8月上旬至9月上旬。11月至翌年4月,因寄主休眠和低温导致虫口缓慢下降。雌成虫产卵量与寄主生长势好坏有关。控制紫薇毡蚧虫口最有效的天敌是红点唇瓢虫Chilocoruskuwanae Silverstri。药液涂干并辅之具内吸作用的杀虫药液灌根是目前较好的药剂防治方法。     

The effect of pyrethroid lambdacyhalothrin applications on the spatial distribution of phytophagous and predatory mites in apple orchards

The spatial distribution of three phytophagous mites,Panonychus ulmi (Koch),Tetranychus urticae Koch andAculus schlechtendali (Nalepa), and two predacious mites,Zetzellia mali (Ewing) andAmblyseius fallacis (Garman), and the effect of pyrethroid lambdacyhalothrin applications on mite spatial dispersion were investigated over a 3-year period in an apple orchard in Ontario. The index of dispersion and the slope of Taylor's power law were used to evaluate dispersion patterns of mites. Panonychus ulmi showed that between-tree spatial variation decreased with an increase of population densities, whereas between-leaf variation increased with population densities. With all other four species it appeared that between-tree variation is much greater than between-leaf variation at all field population density levels. The values ofb by Taylor's power law suggested that all five species of mites are aggregated, but that in generalP. ulmi andT. urticae (b=1.427–1.872) are more aggregated than their predators (b=1.254–1.393). Taylor's regression technique suggests that pyrethroid applications causedP. ulmi, T. urticae, Z. mali andA. fallacis to be less aggregated whileA. schlechtendali was more aggregated. The impact of changes in mite spatial distribution following pyrethroid applications on sampling plans is discussed.     

Fine-scale genetic structure among genetic individuals of the clone-forming monotypic genus Echinosophora koreensis (Fabaceae)

• Background and Aims For rare endemics or endangered plantspecies that reproduce both sexually and vegetatively it iscritical to understand the extent of clonality because assessmentof clonal extent and distribution has important ecological andevolutionary consequences with conservation implications. Asurvey was undertaken to understand clonal effects on fine-scalegenetic structure (FSGS) in two populations (one from a disturbedand the other from an undisturbed locality) of Echinosophorakoreensis, an endangered small shrub belonging to a monotypicgenus in central Korea that reproduces both sexually and vegetativelyvia rhizomes. • Methods Using inter-simple sequence repeats (ISSRs) asgenetic markers, the spatial distribution of individuals wasevaluated using Ripley's L(d)-statistics and quantified thespatial scale of clonal spread and spatial distribution of ISSRgenotypes using spatial autocorrelation analysis techniques(join-count statistics and kinship coefficient, F_ij) for totalsamples and samples excluding clones. • Key Results A high degree of differentiation betweenpopulations was observed (_ST(g) = 0·184, P < 0·001).Ripley's L(d)-statistics revealed a near random distributionof individuals in a disturbed population, whereas significantaggregation of individuals was found in an undisturbed site.The join-count statistics revealed that most clones significantlyaggregate at 6-m interplant distance. The Sp statistic reflectingpatterns of correlograms revealed a strong pattern of FSGS forall four data sets (Sp = 0·072–0·154), butthese patterns were not significantly different from each other.At small interplant distances (2 m), however, jackknifed 95% CIs revealed that the total samples exhibited significantlyhigher F_ij values than the same samples excluding clones. • Conclusion The strong FSGS from genets is consistentwith two biological and ecological traits of E. koreensis: bee-pollinationand limited seed dispersal. Furthermore, potential clone matesover repeated generations would contribute to the observed highF_ij values among genets at short distance. To ensure long-termex situ genetic variability of the endangered E. koreensis,individuals located at distances of 10–12 m should becollected across entire populations of E. koreensis.