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苹果绵蚜为害产量损失测定 总被引：7，自引：0，他引：7
苹果绵蚜为害苹果的树干、枝,新稍及根部,从中吸取大量营养,使寄主生长发育不良,产量降低。经测定苹果绵蚜发生群落数与造成的产量呈负相关,而与产量损失率成正相关,在苹果单株产量108．19～154．20kg,苹果绵蚜群落数±30～＞150个的情况下,小国光和青香蕉品种的产量损失率分别为4．10％～38．81％和7．5％～32．04％。 相似文献
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苹果绵蚜防治技术研究简报 总被引：1，自引：0，他引：1
苹果绵蚜 ( Eriosoma lanigerum Hausmann)俗称绵虫、棉花虫、血色蚜虫 ,是我国规定的植物检疫性有害生物 ,也是苹果属 ( Malus)果树的重要害虫。该虫在烟台发生较普遍 ,为害较严重 ,并有逐渐向非发生地区扩散蔓延为害趋势。为寻找经济、快速、有效的防治方法 ,笔者多年进行了这方面的研究 ,取得显著的效果 ,现简报如下 :1材料与方法在山东海阳、蓬莱、莱州等选择苹果绵蚜发生较重的老果园 ,树龄 2 0 - 30年之间 ,树势中等。供试药剂为 4 0 %氧化乐果乳油 (山东张店农药厂 )。设 5个处理 ,分别是 :( 1 )涂干 :在距地面 50 cm左右的主干处 … 相似文献
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苹果绵蚜发生危害特点及防治对策 总被引：19，自引：1，他引：19
苹果绵蚜主要在我国辽东半岛、胶东半岛和昆明一带局部发生 ,每年 5～ 6月和 9～ 1 0月为害虫发生盛期。近几年来 ,危害逐年加重 ,并不断扩展蔓延 ,对我国苹果的产量和品质构成了严重威胁。该文介绍了苹果绵蚜在我国的危害情况和发生规律 ,分析了其发生与危害的特点 ,并提出了有效防治对策 相似文献
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本文在生物学特性研究的基础上,组建了苹果绵蚜(Eriosoma lanigerum)及其日光蜂(Aphelinus mali)寄主——天敌作用系统的Boxcar train模型,对苹果绵蚜猖獗期的二种群数量进行了模拟,其结果与果园调查基本吻合。用此模型做系统的灵敏度分析,结果表明系统的内部因子(如蚜蜂的基数比例)和外部因子(温湿度)对系统均有影响。温度升高,二种群数量增加,反之则下降。湿度增加,苹果绵蚜日光蜂种群数量上升,反之则下降。湿度变化对苹果绵蚜无不良影响。比较而言,温度对系统的影响比湿度大得多。减少苹果绵蚜基数比增加日光蜂基数对系统的影响大,据此可从理论上估计生物防治的局限性。 相似文献
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果树抗苹绵好Eriosomalanigerum性与多种因素有关。其中营养成分α-氨基氮（α-N）的含量,以及毒性成分多酚（φ）的含量尤为重要[1]。邓家棋等为筛选抗虫性强的品系,采用核梢罩微型笼饲养等方法[2]对本地区多种品系果树进行测试。同时开展了对许多品系枝梢的α－N和φ含量的分析测试工作。结果表明,枝消的总酚含量与α-氨基氮的含量之比（φα－N）与用核稍微型笼饲养法测得的抗虫性具一定的相关性。因此,化学成分的分析对于抗虫性品系的选育具有一定的参考价值。1材料与方法1．1材料：湖北海棠（龙王1,龙王2,龙王3,房县3,房县8… 相似文献
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A multipatch model is proposed to study the impact of travel on the spatial spread of disease between patches with different level of disease prevalence. The basic reproduction number for the ith patch in isolation is obtained along with the basic reproduction number of the system of patches, ℜ0. Inequalities describing the relationship between these numbers are also given. For a two-patch model with one high prevalence patch and one low prevalence patch, results pertaining to the dependence of ℜ0 on the travel rates between the two patches are obtained. For parameter values relevant for influenza, these results show that, while banning travel of infectives from the low to the high prevalence patch always contributes to disease control, banning travel of symptomatic travelers only from the high to the low prevalence patch could adversely affect the containment of the outbreak under certain ranges of parameter values. Moreover, banning all travel of infected individuals from the high to the low prevalence patch could result in the low prevalence patch becoming diseasefree, while the high prevalence patch becomes even more disease-prevalent, with the resulting number of infectives in this patch alone exceeding the combined number of infectives in both patches without border control. Under the set of parameter values used, our results demonstrate that if border control is properly implemented, then it could contribute to stopping the spatial spread of disease between patches. 相似文献
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A simple model for the effect of border control or travel restrictions is proposed. It can be used to predict the corresponding results in quite complex disease spread models and has the advantage of providing easy qualitative understanding of the effects of this kind of intervention. 相似文献
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Epidemics of marine pathogens can spread at extremely rapid rates. For example, herpes virus spread through pilchard populations in Australia at a rate in excess of 10 000 km year?1, and morbillivirus infections in seals and dolphins have spread at more than 3000 km year?1. In terrestrial environments, only the epidemics of myxomatosis and calicivirus in Australian rabbits and West Nile Virus in birds in North America have rates of spread in excess of 1000 km year?1. The rapid rates of spread of these epidemics has been attributed to flying insect vectors, but flying vectors have not been proposed for any marine pathogen. The most likely explanation for the relatively rapid spread of marine pathogens is the lack of barriers to dispersal in some parts of the ocean, and the potential for long‐term survival of pathogens outside the host. These findings caution that pathogens may pose a particularly severe problem in the ocean. There is a need to develop epidemic models capable of generating these high rates of spread and obtain more estimates of disease spread rate. 相似文献
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Gustavo A. Villalona Milissa A. Mckee Karen A. Diefenbach 《The Yale journal of biology and medicine》2013,86(3):385-387
Damage control surgery is a feasible and successful approach for the managementof unstable neonates with intra-abdominal catastrophes, including liverinjuries. We report the case of a premature infant with a liver injury secondaryto the placement of an umbilical vein catheter who was successfully managedusing damage control surgery techniques. 相似文献
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Paul D. Pratt Michael J. Pitcairn Scott Oneto M. Brent Kelley Clayton J. Sodergren Frédéric Beaulieu 《Biocontrol Science and Technology》2019,29(5):494-513
Scotch broom (Cytisus scoparius (L.) Link) is a European shrub that has naturalised in several countries worldwide and is recognised as an invasive weed in much of western North America. The mite Aceria genistae (Nalepa) is a coevolved, gall-inducing herbivore associated with Scotch broom in its native range and has been intentionally introduced as a classical weed biological control agent of C. scoparius in Australia and New Zealand. An adventive, never intentionally introduced, population of A. genistae was discovered in Washington and Oregon, U.S.A. in 2005. Surveys for A. genistae in California resulted in the discovery of the gall mite in 11 counties, with a widely scattered distribution. Molecular and morphological assessments confirm the mites collected from galls in California are A. genistae. Whether natural or anthropogenic, the estimated rate of long range dispersal for A. genistae from Washington or Oregon to California ranges from 39 to 62?km/yr. Niche model predictions indicate that A. genistae will continue to expand its distribution throughout much of the Scotch broom-invaded lands of California but areas supporting the weed in the Eastern U.S.A. appear less suitable. Modelling evidence also indicates that portions of Chile and Argentina are suitable for colonisation by A. genistae, also suggesting that expansion of the mite is possible in areas of Tasmania, southeastern Australia, and New Zealand where the mite was released. The environmental safety of A. genistae in relation to non-target plants and the influence of herbivory on Scotch broom fitness are discussed. 相似文献
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Hildegard Uecker 《Trends in microbiology》2018,26(12):969-970
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The following aspects ofHypoaspis miles' biology were investigated; development rate of egg to adult at different temperatures, fecundity, longevity and rate of predation on sciarids. With an increase in temperature the time taken for development decreased from 33.7 days at 15°C to 9.2 days at 28°C. The threshold temperature forH. miles to complete its life cycle was between 10° and 12°C. When fed onAcarus siro, H. miles laid 2–3 eggs a day and unfertilized eggs only developed into males. Adults ofH. miles (0–1 day old) survived for 24.0±1.4 days without food and if fed for 6 days and then starved, females lived for 65.4±2.6 days which was significantly longer than males (45.2±3.0 days). With food, 60% of males and females survived for 142 days. All larval instars of sciarids were attacked byH. miles although the numbers consumed were dependent on the size of the larvae. Egg predation was negligible and pupae were not attacked. In productivity studies ofH. miles in culture (fed onA. siro), the time taken for the mites to reach a density of 45–65,000/litre ranged from 76 to 23 days at 15° and 28°C respectively.
Résumé Différents aspects de la biologied'Hypoaspis miles sont examinés: vitesse de développement de l'oeuf à l'adulte à différentes températures, fécondité, longévité et voracité sur les sciarides. Avec une augmentation de la température, la durée du développement passe de 33,7 jours à 15°C à 9,2 jours à 28°C. La température minimale qui permet le développement complet deH. miles est située entre 10 et 12°C. Quand il est nourri d'\"itAcarus siro, H. miles pond 2 à 3 oeufs par jour et seuls les oeufs non fécondés donnent des males. Les adultes deH. miles (agés de 0 à 1 jour) survivent pendant 24±1,4 jours sans nourriture et si elles sont nourries pendant 6 jours puis privées de nourriture, les femelles vivent 65,4±2,6 jours, ce qui est significativement plus long que les males (45,2±3 jours). Avec de la nourriture, 60% des males et des femelles vivent pendant 142 jours. Toutes les larves de sciarides sont attaquées parH. miles, mais le nombre de proies consommées dépend de la taille des larves. La prédation des oeufs est négligeable et les pupes ne sont pas attaquées. Dans des études sur la productivité deH. miles en élevage (nourri deA. siro), la durée nécessaire aux acariens pour atteindre une densité de 45–65 000/1 est de 76 et 23 jours à 15°C et 28°C respectivement.相似文献
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