李园桃蚜和草间小黑蛛种群空间格局的地学统计学研究

利用地学统计学的原理和方法分析了李园桃蚜种群和草间小黑蛛种群的空间结构和时间相关性.结果表明,桃蚜种群6月27日和11月22日此两次的半变异函数拟合模型为直线,表明此两次两种空间分布为均匀分布或随机分布,其余9次半变异函数拟合模型均为球形,表明此9次李园桃蚜种群的空间分布是聚集分布,变程RSD(m)为4.173903～34.7837.草间小黑蛛空间格局5月21日、5月31日及10月19日、11月22日4次半变异函数拟合模型为直线,表明此4次种群的空间分布为均匀分布或随机分布,其余8次半变异函数拟合模型均为球形,表明此8次李园草间小黑蛛种群的空间分布是聚集分布,变程RSD(m)为2.3169～42.00711,表明草间小黑蛛种群对桃蚜种群在空间位置上具有追随关系,对其种群数量的控制有较大作用.     

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。     

棉蚜和草间小黑蛛种群空间格局的地统计学研究

应用地统计学的原理和方法研究了石榴园不同时期棉蚜及草间小黑蛛种群的空间结构和空间相关性．结果表明,不同时期棉蚜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7．33～12．40cm之间;草间小黑蛛种群的拟合半变异函数曲线也表现为球型,呈聚集空间格局,空间变程在6．47～20．88cm之间,并与棉蚜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棉蚜种群的优势种天敌．     

桃-点叶蝉及其天敌草间小黑蛛种群三维空间格局动态

对桃树树冠上、中、下3层及东、西、南、北4个方位桃—点叶蝉及其天敌草间小黑蛛的系统调查分析表明,桃—点叶蝉及其天敌草间小黑蛛种群在7个部位的聚集强度其5个判断指数都大于聚集格局的判断标准,证明桃—点叶蝉及其天敌草间小黑蛛种群7个部位均为聚集格局,1wao公式m·=a+βx^-中的α值均大于0。表明个体间互相吸引,其中树冠中层和东面树冠平均拥挤度最高,而树冠下层和南面树冠最低,在时间上平均拥挤度为9月中旬最高．     

桃一点叶蝉及其天敌草间小黑蛛种群三维空间格局动态

对桃树树冠上、中、下3层及东、西、南、北4个方位桃一点叶蝉及其天敌草间小黑蛛的系统调查分析表明,桃一点叶蝉及其天敌草间小黑蛛种群在7个部位的聚集强度其5个判断指数都大于聚集格局的判断标准,证明桃一点叶蝉及其天敌草间小黑蛛种群7个部位均为聚集格局,Iwao公式m=α+βχ中的α值均大于0,表明个体间互相吸引,其中树冠中层和东面树冠平均拥挤度最高,而树冠下层和南面树冠最低,在时间上平均拥挤度为9月中旬最高。     

草间小黑蛛对茶蚜的捕食功能反应

在实验室条件下研究了草间小黑蛛(Erigonidium graminicolum)对茶蚜(Toxoptera aurantii)的捕食作用。草间小黑蛛对茶蚜的捕食功能反应属于HollingⅡ型。草间小黑蛛有较强的种内干扰反应,随着捕食者密度的增大,草间小黑蛛的捕食率相应降低。猎物密度和天敌密度相互干扰会降低草间小黑蛛的寻找效应,但对捕食量没有影响。     

枣园中枣瘿蚊和草间小黑蛛的空间分布格局及空间依赖性

利用地统计学原理和方法,对枣园中枣瘿蚊及其天敌草间小黑蛛种群的空间结构和空间相关性进行了研究.结果表明,6月8日、8月27日、10月19日枣树主要生育期阶段,枣瘿蚊种群的半变异函数模型为球形.在林间基本上呈聚集分布,其样点空间依赖性距离分别为26.3、7.8和22.0 m,其空间依赖性程度分别为88.05%、85.77%和87.58%.草间小黑蛛种群的半变异函数也为球形,呈聚集分布,空间依赖距离分别为28.3、22.5和22.2 m,且在该取样尺度下,总变异中分别有90.09%、87.96%和85.72%是由空间依赖性产生的.两者空间依赖关系说明草间小黑蛛对枣瘿蚊有较强的追随作用.     

桃园生草对桃树节肢动物群落多样性与稳定性的影响

对种植白三叶草的桃园(生草桃园)和非生草桃园的桃树节肢动物群落进行分析比较.结果表明:生草桃园桃树天敌、中性类群和植食类群数量分别是非生草桃园的1.48、1.84和0.64倍,而节肢动物群落个体总数无显著差异;与非生草桃园相比,生草桃园桃树节肢动物群落丰富度(83.733±4.932)、多样性(4.966±0.110)和均匀性指数(0.795±0.014)均显著升高,而优势度指数(0.135±0.012)显著降低.稳定性指数S/N、Sd/Sp与非生草桃园均无显著差异,但Nn/Np、Nd/Np及Sn/Sp均显著高于非生草桃园.生草桃园桃树节肢动物群落多样性与稳定性指数N/Np、Sd/Sp、S/N存在显著的负相关关系,而与Nn/Np、Sn/Sp无相关性;非生草桃园多样性与稳定性指数Nn／Np、Nd/Np存在显著的正相关关系,而与其他稳定性指数无显著相关性.     

恩施烟区无翅桃蚜在烤烟田空间动态的地统计学分析

恩施烟区是湖北省最大烟叶生产基地,桃蚜Myzuspercicae(Sulzer)是恩施烟叶最重要的害虫之一,桃蚜在田间的发生以及传播的病毒病害逐年加重,给烟业生产带来巨大损失。进一步了解桃蚜发生动态和空间分布规律,将提高对桃蚜的预测效果并为其综合防治提供理论依据。烟区和烟田之间的迁移以有翅蚜为主,田块内部的种群动态和发生规律,无翅桃蚜发挥着更加重要的作用。受寄主生理生化特性影响,不同烟叶生育期,桃蚜空间结构的差异需要进一步验证。经典的统计学方法以纯随机变量为基础,而昆虫种群的田间分布存在空间相关性,地学统计学承认空间相关性的存在,为区域化变量的空间分布分析提供新的理论和方法。在烟叶不同生育期进行无翅桃蚜的田间密度调查,运用地统计学的方法分析了其空间特征和发生动态,模拟了无翅桃蚜在烟叶不同生育期的田间分布图,并对无翅桃蚜在不同烟叶生育期田间分布格局的相关性进行了分析。结果表明:无翅桃蚜在烟叶苗期密度最小为(5.59±4.07)头/株,烟叶旺长期虫口密度最大为(14.5±9.6)头/株;种群密度变异系数均较大(0.6147-0.7281),表明其空间分布的不均匀性,并随密度的增大而减小,表明种群密度的增大一定程度上提高了种群结构的稳定性。烟叶苗期的种群分布曲线峰度最大,表现出更高的聚集性。无翅桃蚜在烟叶苗期的135°方向和团棵期的45。方向表现为随机分布。烟叶苗期的0°方向和45°方向可用线性有基台模型拟合,其他均可用球形+指数套合模型拟合,判断球形+指数套合模型是无翅桃蚜田间分布的主要模型,属于聚集型分布的范畴。块金值、基台值和变程均随田间虫口密度的增大而增大,苗期的随机程度(0.1905—0.7186)明显大于其他时期(0.0116—0.1620)。无翅桃蚜空间分布模拟图可以清晰地看出无翅桃蚜苗期迁移,旺长期后逐渐稳定的特性。无翅桃蚜的田间分布在烟叶苗期与团棵期无明显相关性,而团棵期与旺长期以及旺长期与成熟期显著相关,再次证明烟叶苗期到团棵期,无翅桃蚜的田间分布发生较大迁移,而团棵期以后基本定殖。烟叶苗期的无翅桃蚜高度聚集在少数烟株上,及早预防可以减少烟叶苗期虫口基数,有利于桃蚜种群数量的控制。首次将平面坐标系划分为4个方向,更加准确、全面地描述昆虫种群的空间分布特征。     

柑橘全爪螨种群空间格局的地学统计学分析

应用地学统计学方法分析了柑橘园主要害螨柑橘全爪螨Panonychus citri（McGregor）种群的空间格局及其动态。结果表明,柑橘全爪螨种群具有空间相关性,变程介于1．10～21．0m,其半变异函数主要符合高斯模型,表现为聚集分布,其中3月、8月和9月的聚集强度较大;种群空间格局动态显示,4月、10月为该种群的两个发生高峰期,柑橘全爪螨种群数量快速上升扩散。地学统计学方法能够应用于柑橘全爪螨种群的空间格局分析,并有助于对该害螨进行发生预测与控制处理。     

烟蚜及其捕食性天敌草间小黑蛛种群空间结构分析

采用地统计学原理和方法,拟合了不同时期烟蚜种群及其捕食性天敌草间小黑蛛种群的空间结构模型,分析了其空间关系．结果表明,不同时期烟蚜种群的空间结构模型均为球型,空间格局呈聚集型分布,空间相关距离在2．0252～4．1495m之间,异质系数为10281．36～300216．30,空间依赖程度为12176．81～303433．70;不同时期草间小黑蛛种群的空间结构模型也均为球型,空间格局呈聚集型分布,空间相关距离在3．7328～4．8983m之间,异质系数为1．4482～4．4134,空间依赖程度为1．6941～5．8167．该结果和方法可用于监测烟田目标害虫的时空格局动态．     

Organic farming-compatible insecticides against the aphid Myzus persicae (Sulzer) in peach orchards

Abstract:  Three products allowed in organic farming (kaolin, mineral oil and insecticidal soap) as alternatives to chemical insecticides, were evaluated for the control of Myzus persicae (Sulzer) in a peach orchard. Their efficacy was compared with the neonicotinoid imidacloprid and an untreated control. The experiment was replicated for 2 years (2003 and 2004). The products were applied once in May every year and aphid infestation was recorded three to four times post-treatment. In 2004, the effect of the products on the predatory coccinellid species was also recorded. In 2003, all four products showed good control with average Abbott's efficiency ranging from 80% to 88%. In the next year, however, the products were less effective and only imidacloprid and kaolin reduced aphid population significantly compared with the untreated control, with an average Abbott's efficiency of 62% and 31%, respectively. This reduced efficiency was attributed to high rainfall occurring post-treatment. Regarding the effects on beneficial coccinellids, only imidacloprid and mineral oil reduced their numbers after application. The results showed that the three alternative products and especially kaolin are promising for aphid control in peach orchards. Kaolin has also low side-effects on beneficials and it could be used in organic peach orchards.     

Influence of ground cover and herbicide treatments onTetranychus urticae populations in peach orchards

Two-spotted spider mites,Tetranychus urticae Koch, were sampled in peach orchards to quantify abundance in trees over different types of ground cover to document the dispersal of mites from orchard-floor plants to trees. Mite populations developed more quickly and with higher densities in trees over ground cover compared to bare ground, and specifically over covers of predominantly narrowleaf vetch,Vicia angustifolia Reichard. Orchard floor plants such asVicia, Geranium, Lamium, andLepidium contained relatively high densities of mites during early spring, and may have formed the source for later peach-tree infestation.Paper no. 11982 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7643, U.S.A.     

Ecological genetics of host plant exploitation in the green peach aphid, Myzus persicae

The ecological consequences of genetic variability in host plant exploitation of Myzus persicae (Hemiptera, Aphididae) were studied in several agro-ecosystems, differing in crop plant heterogeneity. An analysis of aphid populations sampled from sugar beet, potatoes, and lettuce revealed changes in the frequency distribution of aphid clones according to their respective host plant adaptations. The spatial unit of differentiation was below an average field size of 3–5 hectares and a differentiation could be found in the centre of potato and sugar beet fields but not at the edge of the fields. On a temporal scale, the differentiation of populations is transitory even on a large-scale basis of highly specialized cropping areas. The ecological parameters of differentiation are discussed with special reference to agro-ecosystems and integrated pest management. Increasing the genetic heterogeneity of crop fields may help to reduce population outbreaks.

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Zusammenfassung Die ökologischen Konsequenzen genetischer Variabilität in der Wirtspflanzennutzung von Myzus persicae (Hemiptera, Aphididae) wurden in mehreren Agro-Ökosystemen untersucht, die sich in der Kulturpflanzenheterogenität unterscheiden. Eine Analyse von auf Rüben, Kartoffeln und Salat siedelnden Populationen zeigte eine genetische Differenzierung in Wirtspflanzen-angepaßte Feld-populationen. Die räumliche Einheit solcher Differenzierungen liegt unterhalb einer Feldgröße von 3–5 ha. Eine Differenzierung konnte hier in der Mitte der Felder aber nicht am Rand festgestellt werden. Aus zeitlicher Sicht ist die Differenzierung selbst in großräumigen, spezialisierten Anbaugebieten nur vorübergehend feststellbar. Die ökologischen Parameter der Differenzierung werden besonders in Hinsicht auf die integrierte Schädlingsbekämpfung in Agro-ökosystemen diskutiert. Eine Erhöhung der genetischen Heterogenität von Kulturpflanzenbeständen kann möglicherweise zu einer Verringerung von Blattlaus-Massenvermehrungen beitragen.

     

北方桃园秋季桃蚜发生规律与防控药剂筛选

秋季回迁到桃园的越冬桃蚜是翌年早春危害桃树的主要虫源。为明确秋季北方桃园中桃蚜的回迁发生动态和产卵情况,以及筛选高效防治的药剂,本研究分别在北京、石家庄、泰安、兰州各选1个桃园,采用黄板诱虫,监测秋季桃园内桃蚜的成虫种群和产卵动态;通过田间药效试验,评价藜芦碱、苦参碱和矿物油等3种药剂对秋季桃蚜的田间防治效果。2017年和2018年连续两年的调查结果显示,北方桃园中桃蚜9月初开始回迁,在10月中旬有性雌蚜开始产卵越冬,10月下旬桃蚜数量明显减少。藜芦碱、苦参碱和矿物油处理防治秋季蚜虫,虽然药效较慢,但用药后14 d后防效分别在91.6%、80.6%和66.4%。北方桃园回迁的桃蚜会快速繁殖扩增种群,且秋末产卵量较多,可以在9月中下旬选择喷施藜芦碱控制桃园桃蚜,降低桃蚜种群数量,减轻翌年蚜虫防治的压力。     

Impact of chemical elicitor applications on greenhouse tomato plants and population growth of the green peach aphid, Myzus persicae

Recent advances in the understanding of plant signaling pathways have opened the way for using elicitor‐induced plant resistance as a tactic for protecting plants against arthropod pests. Four common elicitors of induced responses in tomato, Lycopersicon esculentum Mill. (Solanaceae), were evaluated with regard to phytotoxicity, induction of plant defensive proteins, and effects on population growth and fecundity of a common pest, the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae). Ethephon and methyl jasmonate (MJ) treatments caused varying degrees of phytotoxicity. Ethephon caused pronounced changes in plant growth form and severe, dose‐dependent negative impacts on plant growth and flowering. Effects with MJ were milder, but still caused temporary inhibition of development, leading to smaller plants and delayed flowering. The commercial elicitors benzothiadiazole (BTH) and harpin did not cause detectable phytotoxicity. The highest doses of ethephon and MJ significantly increased leaf peroxidase (POD) levels but only MJ treatments significantly increased polyphenol oxidase (PPO) levels. BTH and harpin had no detectable effects on POD and PPO. Populations of green peach aphids grew significantly more slowly on plants treated with BTH or MJ than on control plants or plants treated with harpin or ethephon. Slowed aphid population growth on BTH‐treated plants was due to significant reductions in aphid fecundity, although this was independent of changes in time to onset of reproduction or time to death. Aphid fecundity was also reduced on MJ‐treated plants relative to controls, but this difference was not statistically significant, suggesting that other mechanisms are involved in slowing aphid population growth on MJ‐treated plants. Growth of aphid populations on plants treated with a MJ–BTH mixture was reduced almost as much as with treatments of MJ alone, suggesting that antagonism between JA‐dependant and SA‐dependent plant signaling pathways is only mild with regard to induced defenses against aphids.     

Cytogenetic and molecular characterization of a highly repeated DNA sequence in the peach potato aphid Myzus persicae

Electrophoresis following digestion of Myzus persicae genomic DNA with HindIII showed the presence of a prominent band of approximately 200 bp whereas a faint electrophoretic band corresponding to DNA fragments of about 3000 bp was observed after digestion with ApaI. In situ digestion with restriction enzymes, followed by in situ nick translation, showed that ApaI targets are localized at the nucleolus organizer-bearing X telomeric region, whereas HindIII restriction sites are clustered in intercalary C-positive areas on the same X chromosome. Fluorescent in situ hybridization (FISH) carried out by using digoxygenin-labeled HindIII repeats as probe fully confirmed overlapping between the hybridization sites of this probe and the AT-rich intercalary heterochromatic bands on the X chromosome. These findings, together with published data, allow us to conclude that the M. persicae genome possesses three classes of C-positive heterochromatin: (i) a GC-rich argentophilic band located on one telomere of the X chromosome that contains ApaI targets; (ii) AT-rich intercalary bands located on the X chromosome containing clustered HindIII fragments; (iii) AT-rich telomeric bands, located on autosomes, consisting of HaeIII repeats. Molecular analysis has shown that the length of the HindIII repeat consensus sequence is 189 bp with an AT content of 67%. Southern blotting with HindIII monomers revealed a regular ladder of bands composed of multimers of basic length that are characteristic of satellite DNAs. The HindIII repeat displays other features typical of eukaryotic satellite arrays such as overlapping with heterochromatic bands and a high degree of sequence similarity among monomers (84%–94%). A similarity plot showed that sequences were particularly variable in the 50–100 bp region whereas they proved to be highly conservative in the first 50 bp, thus suggesting that this portion of the repeat might be functionally important. Received: 23 February 1999; in revised form: 21 July 1999 / Accepted: 28 July 1999