轻型飞机防治森林害虫技术

论述海燕650B轻型飞机防治森林害虫的作业技术,系统探讨诸因素与防治效果和作业效率的关系。结果表明,海燕650B轻型飞机在风速小于3m/s,飞行高度在10-25m间,作业速度110km/h时,利用超低量喷洒技术,运用风动式雾化器喷洒白僵菌生物制剂与化学农药的混合剂防治森林害虫,防治效果好,经济效益高。     

应用轻型飞机防治马尾松毛虫的试验Ⅰ.喷施四种药剂防治的效果

马尾松毛虫Dendrolimus punctatus Walker是马尾松林重要害虫.林间应用超轻型飞机大面积喷洒溴氰菊酯超低容量喷雾、白僵菌纯孢子油剂、菌药混合液超低容量喷雾以及喷洒白僵菌菌粉,其防治效果分别为96.5%、85.7%、95.6%、86.5%.上述的防治措施可作为单独的措施或综合防控中的配套措施使用,同时应用飞机防治解决了树高、林密、水源缺乏、劳力工资昂贵等条件给防治工作带来的困难,是一种适应林区林业生产整体水平而又快速、高效、经济的防治手段.     

飞机喷药防治马尾松毛虫对林内昆虫多样性的影响研究

近年我省采用飞机喷药防治森林病虫害的面积不断扩大,本文在飞防区防治前后随机采取昆虫样本,以研究飞防喷药对昆虫及其多样性的影响,采用Bt＋病毒、灭幼脲、苦参碱·烟碱乳油和森得保飞机喷药防治的各试验区内,调查发现飞机喷药防治前后各试验区出现的优势类群均为蜘蛛、鞘翅目、同翅目、膜翅目和双翅目昆虫。灭幼脲和森得保飞机喷药防治后生物多样性指数指数有所增加,且差异显著;Bt＋病毒和苦参碱·烟碱乳油飞防后生物多样性指数指数有变化,但差异不显著。     

应用轻型飞机防治马尾松毛虫的试验Ⅱ.喷施阿维菌素防治的效果

林间应用轻型飞机大面积超低容量喷洒阿维菌素防治马尾松毛虫Dendrolimus punctatus (Walker)幼虫,其防治效果为95%以上.结果表明:阿维菌素能有效地控制马尾松毛虫的大发生,可作为单独的措施或综合防治中的配套措施使用,同时应用飞机防治解决了树高林密、水源缺乏、劳力昂贵等条件给防治工作带来的困难,是一条适应林业生产高效、经济的防治手段.     

讯号伞是山区飞机防治森林虫害的良好导航标志

飞机在地形复杂的山区林份中喷药治虫,除与飞行员的“超低空”机动飞行技术有关外,在绝大程度上还取决于地面讯号队的导航指挥工作。 1963-1964年河南省罗山县先后利用飞机喷药防治马尾松毛虫3次,共飞行近300架次,防治面积达30余万亩。第一次防治采用一米见方的讯号旗导航,由于     

农作物病虫综合防治的新阶段——“健身防治”

<正> 一、综合防治理论依据新探 农作物病虫综合防治是对有害生物(包括病虫草鼠等)的控制和使作物健身的科学管理体系。从这个意义上讲,它应该包含两层意思:一是对有害生物的防治、要求达到控制(检疫对象,要求“零”状态的控制)。二是不能为防治而防治,而应该达到农作物健身保产和增产的目的。 就农作物健身保产和增产而言,它是遵循着农作物对病虫害补偿作用规律的,简单地说,     

浙江杭州发现黄蹼洋海燕

2019年8月11日6:59时,超强台风“利奇马”刚刚离开杭州,在浙江省杭州市西湖水域靠近钱王祠的水域(120°09′05″E,30°14′52″N,海拔约10 m)发现1只海燕。该海燕体型较小,腰部羽毛明显为白色,不似我国东海有分布的黑叉尾海燕现场拍摄的照片显示其腰部白色延伸到尾下覆羽,跗跖较长.     

荒漠与荒漠化

在讨论“荒漠”与“沙漠”概念之基础上,通过熟悉联合国《防治荒漠化公约》对“荒漠化(desertification)”的定义．了解我国专家强调“沙漠化”的缘由,认识荒漠化是当今世界最关注的环境-社会经济问题之一。我国是《防治荒漠化公约》的签约国,实施“西部大开发”战略,必须重视生态环境建设中荒漠化的防治问题,尤其是沙漠化和沙尘暴的防治工作。     

结核病仍是传染病头号杀手

3月24日是第9个“世界防治结核病日”。有关专家呼吁:结核病这个上个世纪曾经猖獗一时的“老”传染病仍然是传染病头号杀手,其防治形势不容乐观。解放军三0九医院全军结核病中心主任王巍告诉记者,今年结核病日的活动主题是“控制结核病,让每一次呼吸更健康”,其目的就是要强调结核病防治的重要性和紧迫性。2000年全国结核病流行病学抽样调查报告显示,我国目前有结核病人500多万,传染性结核病人150万,每年约有13万人死于结核病。结核病死亡在传染病和寄生虫病中仍居第1位。贫困、人口增多、耐药结核病人增多、流动人口的增多以及艾滋病流行,…     

试论稻飞虱的防治策略

<正> 在70年代,根据当时稻飞虱的发生发展,繁殖为害情况和生境条件等提出对稻飞虱“压前控后”的防治策略,对当时防治稻飞虱为害、确保水稻丰收起了一定的作用。随着稻飞虱优势种群的变化,栽培制度的变革、水稻品种的更换、肥水条件的改善、管理水平的提高等,使稻飞虱的生境条件发生了一些变化,在80年代继     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.