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41.
红河地区枣树主要病害种类调查   总被引:1,自引:0,他引:1  
查清了红河地区主要枣树栽培区枣树上发生的主要病害种类为枣锈病、枣黑斑病、枣烂果病等,枣焦叶病、白粉病、缩果病、裂果病等病害在红河地区也有发生,但发病情况较轻;调查了部分枣树病害在该地区的发生规律,并对其发生特点进行了比较。  相似文献   
42.
A rhabdovirus was isolated in cell culture inoculated with tissue material from diseased grayling, Thymallus thymallus (L.), originating from a fish farm affected by a mortality episode in Poland. Diagnostics tests showed that the virus was not related to novirhabdoviruses known in Europe, nor to vesiculovirus‐like species, except perch rhabdovirus (PRhV) with which it shared moderate serological relations. However, RT‐PCR with PRhV probes gave negative results. To identify the virus, a random‐priming sequence‐independent single primer amplification was adopted. Surprisingly, two of the obtained sequences exhibited a high identity (>99%) with hirame rhabdovirus (HIRRV), a novirhabdovirus usually found in fish in marine Asiatic countries, for instance Japan, China and Korea. The full‐length sequence of the phosphoprotein gene (P) demonstrated a higher identity of the present isolate with HIRRV from China compared with the Korean isolate. An identical viral sequence was also found in brown trout, Salmo trutta trutta L., affected by mortalities in a second farm in the same region, after a likely contamination from the grayling farm. To our knowledge, this is the first report of HIRRV in Europe, and in two hosts from fresh water that have not been described before as susceptible species.  相似文献   
43.
甜菜筒喙象是世界潜在入侵象虫网收录的一种重要象甲科昆虫,主要为害甜菜,以及藜科、苋科和蓼科的一些杂草,国内外未曾见有为害藜麦的报道,2016年7月下旬我们发现该种象虫在北京严重为害藜麦。本文首次报道甜菜筒喙象在藜麦上的发生为害情况,同时介绍了其形态识别特征、生物学特性,给出了防治建议,并提出下一步研究重点,为有效防范甜菜筒喙象的进一步扩散为害,保障我国藜麦产业的健康发展提供科学支撑。  相似文献   
44.
In the 2‐week period following a Standardbred yearling sale, 5 horses from the sale died or were subjected to euthanasia. Three were confirmed as equine herpesvirus type 1 myeloencephalopathy (EHM), while EHM was suspected in 2. Clinical abnormalities were reported in 77 of 177 (43.5%) other yearlings during the 14‐day period after the sale; however, no diagnostic testing was performed. Eleven secondary cases of suspected EHM in horses in contact with yearlings purchased at the sale were identified. No cases of EHM were identified associated with the same sale in 2003; however, there was no difference in morbidity with clinical abnormalities reported in 39/96 (41%) horses sold that year (P = 0.70). Yearling sales have an inherent risk of pathogen exposure and illness is common in purchased horses. Disease in these horses could have been associated with a wide range of respiratory pathogens; however, the incidence of confirmed or suspected primary and secondary EHM cases associated with the 2002 yearling sale highlight the potential for significant outbreaks of disease.  相似文献   
45.
草地蝗虫发生原因及可持续管理对策   总被引:8,自引:0,他引:8  
本研究探讨了影响草地蝗虫数量动态变化的主要因素,并就如何实现草地蝗虫的可持续管理对策做了较为系统全面的概述。认为全球气候温暖化、干旱化以及区域性气候异常,食物资源,种间种内竞争,环境因子以及草地利用方式和强度等是导致草地蝗虫数量动态变化以及可能引发蝗虫灾害的主要原因。同时提出基于生态安全、经济有效和草地生态系统可持续发展的原则作为管理草地蝗虫的指导方针。最后,将强化蝗虫发生机理及预测预报技术研究,积极探索草地管理措施在调节蝗虫数量中发挥作用,尝试草地蝗虫管理新的方法和技术,扩大生物防治范围和力度并确立新型化学防治技术作为实现草地蝗虫可持续管理的主要措施。  相似文献   
46.
[目的]明确2008年石河子地区葡萄烂果病大发生的主要原因.[方法]通过田间调查、室内品种抗性鉴定与大田品种抗病性调查及实地了解病害发生整个过程中的田间管理措施,特别是激素使用次数和用量等,查阅相关气象资料,比较不同单位、不同年度间相关措施和烂果程度间的差异,从而找出引起烂果病大发生的主要原因.[结果]2008年石河子地区葡萄烂果病发生最严重的品种是无核紫,激素使用次数过多和过量导致裂果,是诱发烂果病发生的主要原因,8月上旬的久旱遇雨对该病发生也有明显促进作用.[结论]引起2008年石河子地区葡萄大量烂果主要与品种、激素使用过量和气候有关.  相似文献   
47.
通过对健康桑树人为接种病原菌诱导发病,探索了几种药剂对桑疫病的田间防治效果。试验结果显示,CH1000倍对桑疫病具有较高防治效果。处理后15天调查,CH1000倍先接种区和先喷药区的防治效果均达到82%以上,并高于环丙沙星,其余参试药剂效果较差。处理后27天调查,CH1000倍先喷药区防治效果仍达到82%以上,其余处理效果均较差。  相似文献   
48.
The frequency and intensity of ecosystem disturbance, including outbreaks of forest insects and forest fires, is expected to increase in the future as a result of higher temperatures and prolonged drought. While many studies have concentrated on the future climatic impacts on fire, little is known about the impact of future climate on insect infestation. Paleoecological techniques are important in this regard in identifying the potential relationships between climate and insect outbreaks in the past, as a predictive tool for the future. We examine a high-resolution 20th century record of spruce beetle (Dendroctonus rufipennis) infestation from a small, subalpine lake, comparing the paleoecological record to the historical and tree-ring record of the event. An extensive spruce beetle outbreak occurred in northwestern Colorado during the 1940s and 1950s, causing widespread mortality of mature Picea engelmannii. Pollen analysis of this period documents the decline of Picea and its replacement locally by Abies lasiocarpa, paralleling age and composition studies of modern forest stands in the region. This study is a proof of concept that, when applied to longer sedimentary records, could produce a detailed record of infestation for the Late Holocene or older time periods. This information will be useful to forest managers in efforts to plan for the effects of D. rufipennis infestations, and subsequent succession within high elevation conifer forests.  相似文献   
49.
基于MaxEnt和DIVA-GIS的亮壮异蝽潜在地理分布预测   总被引:2,自引:1,他引:1  
亮壮异蝽Urochela distincta Distant为中国特有种,具有结群迁飞和抱团越夏的习性,近年在江西武功山和仙姑坛风景区暴发成灾,为使相关自然保护区及风景名胜区做好对亮壮异蝽种群暴发的早期预警和监测,采用Max Ent和DIVA-GIS软件,基于该虫在江西、湖南、贵州等地的分布数据及相关的20个环境变量,对其潜在地理分布进行了预测。结果表明,影响亮壮异蝽分布的主要环境变量包括最干月降雨量、海拔、昼夜温差月平均值、最暖季降雨量、最冷月最低温、昼夜温差与年温差比值、最干季平均温和最湿季平均温,其中最干月降雨量和海拔是最重要的因素,贡献率分别为64.9%和19.5%。该虫在我国的高适生区多属于海拔700~1 500 m且最干月降雨量为25~130 mm的地区,主要集中在我国动物地理区划的华中区、华南区和西南区东部的部分区域,如江西与湖南交接的罗霄山脉,江西与福建接壤的武夷山山脉,以及重庆、湖南、贵州和湖北四交之地的武陵山脉等;非适生区包括我国的北部地区、西部地区、华中部分地区及华南的小部分区域。  相似文献   
50.
Reptiles are one of the fastest growing sectors in the United States pet industry. Reptile‐associated salmonellosis (RAS) continues to be an important public health problem, especially among children. We investigated an outbreak of human Salmonella infections resulting from serotypes Cotham and Kisarawe, predominately occurring among children. An outbreak of illnesses was identified in persons with exposure to pet bearded dragon lizards. Human and animal health officials, in cooperation with the pet industry, conducted epidemiologic, traceback and laboratory investigations. Onsite sampling was conducted at two US breeding facilities, one foreign breeding facility, and a large pet retail chain. A total of 166 patients in 36 states were identified with illness onset dates from 02/2012–06/2014. The median patient age was 3 years (range, <1–79 years), 57% were aged ≤5 years, and 37% were aged ≤1 year. Forty‐four patients (37%) were hospitalized, predominantly children. Sampling at breeding facilities and a national pet store chain resulted in isolation of outbreak serotypes at each facility; isolation proportions ranged from 2%–24% of samples collected at each facility.Epidemiologic, microbiologic and traceback evidence linked an outbreak of uncommon Salmonella serotypes to contact with pet bearded dragons. The high proportion of infants involved in this outbreak highlights the need to educate owners about the risk of RAS in children and the potential for household contamination by pet reptiles or their habitats. Strategies should be developed to improve breeding practices, biosecurity and monitoring protocols to reduce Salmonella in the pet reptile trade.  相似文献   
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