食虫瘤胸蛛、草间小黑蛛的发生和抗药性测定

食虫瘤胸蛛和草间小黑蛛是川东地区稻田和旱地蜘蛛种群中的优势种,是稻田和旱地部分主要害虫的重要天敌,对稻飞虱日食量为3—6.5头。现将这两种蜘蛛的发生和抗药性测定结果报道于下。     

食虫沟瘤蛛的饥饿耐受性

对我国多数稻区共享的优势种蜘蛛食虫沟瘤蛛进行饥饿耐受性测定,结果显示食虫沟瘤蛛的耐饥时间以及组内个体耐饥力的变异幅度与温度高低呈负相关。在35、25℃和15℃3种试验温度下,食虫沟瘤蛛的耐饥时间及变异幅度均与龄期呈正相关;在5℃时,耐饥时间极大延长,组内变异系幅度亦急剧增大,但此时耐饥时间和变异幅度均与龄期呈负相关。在高温35℃和低温5℃下,3个龄期组的耐饥时间差异不显著(p>0.05);但在适宜温度25℃和15℃时,3个龄期组之间的耐饥时间差异显著(p<0.05)。同一龄期组的食虫沟瘤蛛在任意两种不同的温度条件下,其耐饥时间的差异性均达到极显著水平(p<0.01)。4种试验温度条件下,处于饥饿状态的食虫沟瘤蛛各龄期组的阶段死亡率均具有正态分布特点,可用正态分布模型M=1σ2π.e-(T2-σ2μ)2进行拟合;并可根据正态分布的特点得出食虫沟瘤蛛的饥饿半致死时间(T50)和致死时间(T95)。     

四种微蛛卵袋的形态和护卵习性的观察

本文通过室内饲养和室外观察,对四种微蛛(草间小黑蛛)、驼背额角蛛、食虫瘤胸蛛和隆背微蛛)的卵袋形态特征及其护卵习性进行了较详尽的比较和描述,对于它们各自卵袋的识别和生物学特性的了解有一定的参考价值,为其保护和利用提供资料。     

稻田蜘蛛初步研究

一、稻田蜘蛛种类和优势种 1975—1977年的7—10月上旬在我省赣州、瑞金、会昌、遂川、泰和、井冈山、铜鼓、万载、宜春、九江、武宁、都昌、景德镇市、金溪、宜黄、崇仁、南昌等地调查,发现稻田蜘蛛约40种,已鉴定学名的有10科32种(表1)。其中以草间小黑蛛、食虫瘤胸蛛、八斑球腹蛛、拟环狼蛛、克氏狼蛛分布最广,对稻飞虱、稻叶蝉等多种稻虫有一定的自然控制效应。     

田埂留草控制稻飞虱效果及对捕食性天敌多样性影响

为探讨稻田田埂保留杂草控制稻飞虱的效果及对捕食性天敌多样性的影响,以稻田田埂周年性保留杂草为处理,以稻田田埂不保留杂草为对照,对处理区和对照区稻田稻飞虱成若虫、捕食性天敌种类和数量进行系统调查和分析。结果表明,在调查期内(6—10月),田埂留草稻田百丛稻株稻飞虱数量为(891.11±133.12)头,较非留草稻田减少35.31%;田埂留草稻田捕食性天敌隶属5目23科35种,而田埂非留草稻田隶属5目21科33种;田埂非留草稻田捕食性天敌优势种为食虫沟瘤蛛Ummeliata insecticepsBoes.etStr.、拟水狼蛛Pirata subpiraticus Boes.etStr.和黑肩绿盲蝽Cyrtorrhinus livdipennis Reuter,而田埂留草后优势种为食虫沟瘤蛛U.insecticeps、草间小黑蛛Erigonidium graminicolum(Sundevall)、拟水狼蛛和拟环纹狼蛛Lycosa pseudoamulata(Bose.etStr.);田埂留草稻田捕食性天敌的个体数量、丰富度、多样性指数分别为(128.89±13.52)、(33.67±0.50)、(4.53±0.04)头/百丛,较田埂非留草稻田分别增加31.96%、25.73%、5.59%,而优势度指数和均匀性指数没有显著变化。研究结果为发展稻田景观多样化控害提供依据。     

荧光物示踪法测定重复施药胁迫下食虫沟瘤蛛的摄食量动态

定量评价农药对天敌的影响是IPM研究的重要内容之一,由于对天敌的捕食量缺乏有效的定量测量方法,农药对天敌摄食功能影响仍处于定性水平的研究,误差基数较大。本文采用一种定量的测定方法——荧光物示踪法,以稀土元素铕作为荧光示踪物质,定量地测定了食虫沟瘤蛛在重复接受噻嗪酮喷施后,其存活个体在药后13天内摄食量的变化趋势,且把药后食虫沟瘤蛛的死亡率加以考虑,计算药后整个试验食虫沟瘤蛛群体的摄食量变化。结果表明：任何浓度任何一次施药后2天左右食虫沟瘤蛛存活个体的捕食量均急剧下降;药物浓度较低时,第1次施药对食虫沟瘤蛛的影响最大;药物浓度较高时,食虫沟瘤蛛存活个体药后摄食量恢复周期较长。药后一段时间内整个食虫沟瘤蛛种群的摄食率相当低下,高浓度农药处理的食虫沟瘤蛛组3次施药后13天内的平均种群摄食率只有正常状况下的1/4左右（24.44%）,推荐浓度及低于推荐浓度的食虫沟瘤蛛种群摄食率也仅为对照组的1/3左右（38.69%,36.52%）。因此在对水稻虫害防治时,应当尽可能地避免使用化学农药,充分发挥天敌对害虫数量的调控作用;当害虫数量超过经济阈值而必须施药时,也应当掌握农药用药剂量和次数的尺度,以利于食虫沟瘤蛛等稻田天敌的生理恢复和群落重建。     

稻田蜘蛛群落优势种群的重建

研究稻田蜘蛛群落优势种食虫沟瘤蛛Ｕｍｍｅｌｉａｔａ ｉｎｓｅｃｔｉｃｅｐｓ Ｂｏｅｓ．ｅｔ Ｓｔｒ．和拟水狼蛛Ｐｉｒａｔａ ｓｕｂｐｉｒａｔｉｃｕｓ（Ｂｏｅｓ．ｅｔ Ｓｔｒ．）种群的重建过程。食虫沟瘤蛛种群的重建过程基本上体现过程基本上体现了由近而远、由稀而密的规律;拟水狼蛛种群则只能观察琉由稀布密的现象。采取适当的措施保护种库,增加种库中食虫沟瘤蛛和拟水蛛的数量,将有助于稻田蜘蛛群落优势种群的重     

荧光物示踪法测定除草剂对食虫沟瘤蛛摄食量的影响

采用一种全新的测定方法——荧光物示踪法,以稀土元素铕作为荧光示踪物质,以“水稻 白背飞虱Sogatella furcifera Horvath食虫沟瘤蛛 Ummeliata insecticeps Bosenberg et Strand”这一食物链中的水稻和白背飞虱作为铕的传递者,经萃取和反萃取等一系列化学分析方法,定量地测定了3种除草剂胁迫下食虫沟瘤蛛的摄食量。结果表明：施用除草剂西草净、使它隆和高效盖草能以后,食虫沟瘤蛛的存活个体12天内平均每天捕食白背飞虱分别为1.784、2.678和2.856头,均低于对照组的平均个体摄食量3.321头/d; 各组12天内个体摄食量的趋势线均为开口向上的抛物线,可用二次方程进行拟合; 同时除草剂的喷施亦对食虫沟瘤蛛造成一定的致死率,因而造成施药后食虫沟瘤蛛的种群摄食率减退,第2、5、8天的平均摄食率分别为对照组的52.11%、36.45%和50.27%; 药后第12天3个处理组的摄食量均超过了正常值,平均摄食率达到对照组的131.84%。因此在稻田中害虫大发生或天敌群落迁移时应慎用除草剂,以免食虫沟瘤蛛药后摄食量减少导致对目标害虫控制力减弱或由于除草剂的致死力而对食虫沟瘤蛛的群落重建构成威胁。     

温度对黄褐新圆蛛(Neoscona doenitzi)历期和繁殖力的影响

在20—35℃温度范围内,随着温度升高黄褐新圆蛛发育历期逐渐缩短。其发育速率随温度增加的拐点约为25℃。雌蛛历期长于雄蛛历期,相差1—3天。发育历期随温度升高而缩短的极限值:雌蛛为24天,雄蛛为22天。幼蛛的死亡率随龄期的增长而逐渐减少。全代的发育起点温度为10.35℃,有效积温为738.19日度。 25—30℃为繁殖的最适温度。在该温度条件下,产卵袋致多、产卵总量多、孵化率也高。产的卵袋效与卵粒致总量成正比关系。     

稻田蜘蛛优势种对飞虱对叶蝉控制力的分析

系统调查结果表明,长沙地区早稻田中,蜘蛛优势种相对稳定,在水稻各生育期内均为拟水狼蛛和食虫沟瘤蛛,并无更替现象,采用灰色关联分析法,研究了长沙地区稻田蜘蛛优势种群对飞虱,叶蝉种群数量的控制程度,结果表明拟水狼蛛和食品沟瘤蛛对飞 虱,叶蝉种 数量影响最大,其次为锥腹肖蛸和八斑鞘腹蛛,当拟水狼蛛与飞虱之比为1：20．2,食虫沟瘤蛛与飞虱之比为1：14．5以上时,蜘蛛对飞虱显示出明显的控制力。     

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.