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1.
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 ~21.0 m,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。  相似文献   

2.
采用聚集度指标分析了山楂叶螨聚集强度的时序变化,以指数模型进行拟合数量动态,运用最优分割法分析了山楂叶螨在香梨上的种群动态。山楂叶螨在香梨上的空间格局为聚集分布,分布的基本成分为个体群,聚集强度与叶螨的密度有关。山楂叶螨在香梨上呈指数增长,模型为Nt=15.199 4e0.054 t(R=0.913 2**);将山楂叶螨种群动态划分为3个阶段:发展期、高峰期和衰退期。  相似文献   

3.
荔枝瘿螨是为害荔枝的一类重要害虫,体型小、种类多、分布广。随着荔枝种植面积的扩大、荔枝果实和荔枝苗木的远距离运输,给荔枝瘿螨的传播创造了条件。本文主要总结了国内荔枝瘿螨的研究结果,阐明了荔枝瘿螨的种类及其分布特点;以荔枝瘤瘿螨Aceria litchii和荔枝分位瘿螨Disella litchii为例,阐述了荔枝瘿螨的生物学特性及种群动态、天敌、寄主(荔枝品种)的抗虫(瘿螨)性、种群监测技术、防治措施等方面的研究进展。结合产业发展,指出生产中亟待解决的问题和研究方向,并提出建立“以农业防治为基础、生物防治相结合、化学防控为辅助”的荔枝瘿螨综合防控技术体系的具体措施。  相似文献   

4.
以登记药剂40%哒螨·乙螨唑乳油为对照药剂,研究了多种杀螨剂对枸杞瘿螨的田间药效。结果表明,两次用药后,各供试药剂在其低、中、高剂量下对枸杞瘿螨均表现出一定防效。其中,高剂量处理第2次施药后7 d防效在72%以上,以阿维菌素防效最高,为90.70%,显著高于其他药剂。药后14 d,各药剂高剂量处理防效有升有降,总体变幅不大,均在73%以上。各药剂低剂量处理在第2次药后7d对枸杞瘿螨的防效达53%以上,14 d防效达63%以上。  相似文献   

5.
吡螨胺和哒螨灵亚致死剂量对截形叶螨的亚致死效应   总被引:1,自引:0,他引:1  
通过吡螨胺(tebufenpyrad)和哒螨灵(pyridaben)的亚致死剂量处理截形叶螨(Tetranychustruncatus Ehara)成螨和螨卵,研究了两药剂对实验种群的亚致死效应。结果表明:吡螨胺和哒螨灵处理后当代成螨的每雌日均产卵量均有不同程度的降低,日平均产卵量、卵孵化率均低于对照; F1的卵期、幼螨期、若螨期延长显著,净增殖率低于对照、内禀增长率和周限增长率与对照差异不大。两药剂处理卵后,卵期、幼螨期、若螨期延长,净增殖率低于对照。吡螨胺和哒螨灵的亚致死剂量处理截形叶螨成螨和螨卵都无刺激增殖的作用,能延缓种群的发育速度。  相似文献   

6.
栗瘿蜂的抽样调查及林间分布研究   总被引:2,自引:0,他引:2  
本文比较了三种栗瘿蜂种群抽样调查方法,报出了栗瘿蜂抽样调查最适抽样数。应用Iwao聚集度回归法确定栗瘿蜂在板栗林中的分布为聚集分布,主要分布于板栗树冠中层栗芽中,且技条上部采芽中数量较多。  相似文献   

7.
根据田间实际调查结果,应用5种聚集度指标和Iwao法分析了镰螯螨在人为干扰因素较小的苹果园内种群的发生动态和空间格局.结果表明:7-10月,镰螯螨种群数量随着时间变化表现为先升高后降低的趋势,8月初达到发生高峰期.除树冠下层呈现均匀分布外,其他部位均呈现聚集分布,分布的基本成分是个体群.8月1日到10月1日,各部位间种群聚集度变化平稳;10月1日到10月16日,树冠下层、西面和北面的聚集度略有增高.在苹果园生态系统中,芬兰真绥螨、叶螨、镰螯螨三者不仅相互制约而且相互依存.当果园内叶螨种群数量随捕食螨的作用而降低到较低水平后,镰螯螨作为主要捕食螨—芬兰真绥螨的重要补充猎物,对于维持芬兰真绥螨一定的种群数量和苹果园生物多样性及其数量的动态平衡具有十分重要的作用.  相似文献   

8.
在田间调查基础上,研究了竹笋基夜蛾[Kumasia kumaso(Sugi)]幼虫在早竹林和红哺鸡竹林中的种群动态.结果表明,竹笋基夜蛾幼虫在两种竹林中种群消长曲线均呈倒V形变化.种群密度高峰期出现在4月下旬,在红哺鸡竹林中种群密度高峰较在早竹林中推迟约6d.通过频次分析法和9种聚集度指标对竹笋基夜蛾幼虫在早竹和红哺鸡竹林内的空间分布型进行了测定.结果表明,竹笋基夜蛾幼虫在两种寄主竹林中的空间分布格局均符合Neyman分布和P-E核心分布2种分布模型.各聚集度指标也均表明竹笋基夜蛾在早竹和红哺鸡竹林中呈现聚集分布.聚集原因是由于环境因素引起的.  相似文献   

9.
桃李间作对桃树上节肢动物群落的影响   总被引:2,自引:0,他引:2  
2006年和2007年,对桃李间作果园和单作桃园害虫和天敌进行了调查。通过对主要害虫山楂叶螨(Tetranychus viennensis Zacher)和梨小食心虫[Grapholitha molesta (Busck)]种群动态的比较分析,发现桃李间作可以增加桃树上山楂叶螨的种群数量;从空间分布的角度发现,当梨小食心虫密度高时桃李间作可以降低梨小食心虫的空间分布聚集程度。天敌功能团的典范对应分析表明桃李间作对天敌群落的影响是不稳定的。  相似文献   

10.
应用空间分布型统计参数IwaoM—X模型中α,β及6个聚集指标分析柑橘全爪螨的空间格局,结果表明,柑橘全爪螨的空间格局为聚集型。在此基础上,研究提出了估算柑橘全爪螨在不同虫口密度情况下的理论抽样数。  相似文献   

11.
Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.  相似文献   

12.
Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.  相似文献   

13.
Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.  相似文献   

14.
We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.  相似文献   

15.
The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.  相似文献   

16.
Plant Viruses Transmitted by Whiteflies   总被引:18,自引:0,他引:18  
One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.  相似文献   

17.
《干旱区科学》2014,(6):782-782
正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad  相似文献   

18.
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.  相似文献   

19.
Solacol®, a formulation of the antibiotic validamycin, at 0.33% in 2% malt extract agar, reduced the spread of fungi on dilution plates drastically and allowed twice as much incubation time before subculturing; this resulted in an elevated number of species isolated. Using pure cultures of 62 common soil fungi, it was shown that all fast-growing species (exceptPythium ultimum) were efficiently inhibited but not completely suppressed. Inhibition was comparable to that by 0.5% oxgall, though, while this substance completely suppressed several species, Solacol very strongly inhibited onlyGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum andRhizoctonia solani. In a further experiment each separate constituent of Solacol was tested against 22 fungi at equivalent concentrations. Validamycin strongly inhibitedChaetomium globosum and two Basidiomycetes, though hardly more than the non-ionic detergent which mainly inhibited the other fungi. A few species were, however, more inhibited by Solacol than by the detergent alone. Solacol at 0.33% is a suitable aid in dilution plating of soil fungi, by increasing the number of colonies and species observed.Samenvatting Solacol®, een formulering van het antibioticum validamycine, remde de groei van schimmels in verdunningsplaten met een concentratie van 0.33% in 2% moutagar en maakte het mogelijk de periode tot afenten met een factor 2 te verlengen; daardoor was het aantal geïsoleerde soorten duidelijk toegenomen. Met reincultures van 62 algemene grondschimmelsoorten werd aangetoond, dat alle snelgroeiende soorten (met uitzondering vanPythium ultimum) voldoende geremd, maar niet volkomen onderdrukt werden. Het remmingspercentage was vergelijkbaar met dat van 0.5% ossegal, hoewel dit laatste sommige soorten volkomen onderdrukte; Solacol remde alleenGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum enRhizoctonia solani zeer sterk. In een volgend experiment werden de componenten van Solacol t.o.v. 22 fungi apart getoetst in concentraties equivalent aan 0.33% Solacol. Validamycine remde alleenChaetomium globosum en twee basidiomyceten behoorlijk, maar nauwelijks meer dan de niet-ionische uitvloeier, die in hoofdzaak de overige remeffecten veroorzaakte. Enkele soorten werden echter door het complete Solacol veel sterker geremd dan door de uitvloeier alleen. Solacol in een verdunning van 0,33% wordt aanbevolen bij verdunningsplaten voor het isoleren van grondschimmels ten einde het aantal kolonies en soorten te verhogen.  相似文献   

20.
A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVYN strain and six to the PVYO strain. No PVYC was found. Two other isolates reacted serologically like PVYO, but were unable to elicit a hypersensitive response from the Nytbr gene and probably represent the PVYZ group. At the molecular level, these two isolates showed a combination of both PVYO and PVYN and could be recombinants of these strains. Another isolate reacted serologically like PVYO, but induced vein necrosis in tobacco, like PVYN-Wilga. Some PVYN isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVYNTN group. The PVYNTN, PVYN-Wilga and PVYZ groups probably represent pathotypes within strains PVYN and PVYO, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.  相似文献   

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