共查询到17条相似文献，搜索用时 202 毫秒
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对华北地区经济树种蚧虫的种类区系、发生和分布规律及为害特点进行了系统研究。据调查，现已知华北经济树种蚧虫共有９科１２２种。随纬度增高、立地条件恶化、植物群落简单、人为活动频繁、管理水平粗放，蚧虫种类增多，为害严重。一般情况下，观赏树木受害普遍，温室植物受害严重，果树及平原地区林木部分受害，山地森林受害轻微。 相似文献
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北方温室内蚧虫有６科５１种，其中，以盾蚧科、粉蚧科、蚧科种类为主。植物以多年生、常绿、木本种类受害严重；温室以永久性观赏型和管理粗放的类型蚧害严重；蚧虫以多世代、多食性种类发生严重，并且具有世代重叠、发生量大、蔓延快的特点。最后提出了温室蚧虫的治理对策。 相似文献
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近年来，克拉玛依生态新垦宜农区杨树不同程度地遭到蚧壳虫的危害，林木平均受害率达到15％，严重的林带高达60％。若不加有效防治，3-5年内可将防护林体系中杨树毁灭。为了能够有效消灭杨树蚧壳虫，巩固植树造林成果，提高林木成活率、保存率，确保林纸工程顺利实施，在杨树蚧壳虫防治工作中，我们认真贯彻“预防为主、综合防治”的植保方针，因时、因地、因虫制宜地采用农业、生物、物理、化学、生态等综合防治措施，使其得到有效控制，取得良好的经济、生态和社会效益。现将克拉玛依生态新垦宜农区杨树蚧壳虫发生特点及防治关键技术措施介绍如下。 相似文献
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皱绒粉蚧(Eriococcus rugosus wang)属蚧总科,绒蚧属。我市现有毛竹林4,500多亩,受皱绒粉蚧为害较重的成园毛竹林达1,000多亩,严重地影响竹林的正常生长。1980—1984年,我们在青山蚕桑场进行了此虫生物学特性的观察。现将资料整理于下: 一、寄主及危害 皱绒粉蚧在我市主害毛竹,亦能危害刚竹。 此虫以若虫寄生于1—2年生竹嫩梢叶鞘内,初期每叶鞘可寄生多头,最后成活只1—2头。被害后的嫩梢先发黄,抽新梢少,严重受害的枯死,一般受害的竹林,出现霉污 相似文献
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南疆垦区果树又一重要害虫—橄榄片盾蚧 总被引：1，自引：0，他引：1
南疆的果树近年来受蚧壳虫危害日趋严重，每年因外壳虫危害所造成的直接经济损失都在百万元以上，受害果品表面布满蚧虫，凸凹不平，斑斑点点；受害果树树势衰弱，严重者死亡，已严重影响了垦区及地方果树业的发展。1994年，我们对南疆库尔勒，阿克苏垦区的果树蚧壳虫调查，发现除原有的蚧虫外，又有一重要害虫危害果树。经专家鉴定为橄摊片盾蚧，此蚧虫在南疆果品生产区分布广、危害严重。我们现将该盾蚧及防治方法介绍给读者。一、学名橄说片盾蚧Parlatoriadeae（Colvee）二、分布及为害橄榄片盾蚧在国外分布较广，国内分布于陕西、新疆… 相似文献
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林木检疫对象杨圆蚧Quadraspidiotus gigas(Thiem et Gemeck)近年来在我国部分地区相继发生严重为害,而且在有些地区还与其近缘种梨圆蚧Quadra-spidiotus perniciosus(Comstock)交错分布,这两种蚧虫在其分布区内有着共同的寄主,对各种杨树的为害程度因品种而异。 相似文献
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草履蚧(Drosicah corpulenta kuwana)又名桑虱、草鞋虫、树虱子,属同翅目珠蚧科.该虫在睢宁县的杨树上发生普遍,为害意大利杨的不同品种和无性系,对杨树丰产林和四旁绿化树种造成严重危害. 相似文献
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黑蚱Crytotypana atrato Fabricius.属蝉科,主要为害槐、柳、杨、柑桔、苹果等多种树木。近年来,该虫在徐州地区严重为害杨树人工幼林,主要以成虫在杨树嫩枝刻槽产卵使受害部位及以上组织坏死,受害枝易遭风折,主梢被害后形成多头梢或干形弯曲,严重地影响了杨树 相似文献
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《Forest Ecology and Management》1999,121(3):239-250
Nothofagus nervosa (=N. alpina) is one of the most important native forest tree species of Argentina, with a very small natural distribution area, fast growth and a high wood quality. Its overexploitation in the past seriously affected some populations and made others disappear, making it necessary to implement conservation policies and breeding programs.In order to study the genetic and geographic variation of the species, seeds from a total of 29 populations from the entire natural distribution area in Argentina were harvested, 11 of them during four consecutive years. Annual and geographic covariation of seed production, seed weight and proportion of seeds damaged by insects were analyzed.Significant differences among populations and among years for all studied traits were found. Seed production was highly variable, both among populations and among years. `Partial mast years' seem to occur every two years, whereas the occurrence of `full mast years' has a lower frequency. A significant population × year interaction was found both for the proportion of damaged seeds and for the seed weight. The proportion of seeds damaged by insects was very important, reaching >80% of the total seed produced in some populations. The differences in the quantity of attacked seeds among years are discussed in relation to seed production, insect's life cycle and climatic factors. Seed weight was also variable among populations and years, despite the small natural distribution area of the species in Argentina. Best seed quality, according to lower proportion of damaged seeds and higher seed weight, was observed in the analyzed `full mast year'. This would also imply a better genetic representation of populations with seed samples harvested during these years. A lower proportion of damaged seeds as well as the heaviest seeds were also found among those seeds fallen during the first part of the seed-fall period.The found covariation is discussed in relation to patterns of genetic variation previously found in this species and to the implementation of genetic studies and conservation and breeding programs. 相似文献
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对政和县受害严重的竹林，采用竹腔注射40％的氧化乐果、水胺硫磷等几种农药，并按不同比例、不同时间、筛选出最佳防治措施，害虫死亡率达98％以上。同时对竹小蜂、竹介壳虫等害虫也有毒杀效果，此方法适合于远离村庄、且交通不便的高山地带的竹林，是一种具有广泛推广意义的防治方法。 相似文献
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