长尾潜蝇茧蜂对橘小实蝇幼虫的寄生效能

以橘小实蝇幼虫为寄主,在(25±1)℃,RH(70±10)%,光照周期14L∶10D的条件下,研究了在不同密度的寄生蜂与寄主条件下的长尾潜蝇茧蜂寄生效能。结果表明:不同密度的橘小实蝇幼虫对长尾潜蝇茧蜂的寄生作用有明显的影响,其寄生效应符合功能反应模型HollingⅡ型,方程为Na=0.7291No/(1 0.02362No)。长尾潜蝇茧蜂自身密度对寄生作用也存在干扰效应,用Hassell-Varley模型可表示为a=0.1993P-0.2966。     

阿里山潜蝇茧蜂对橘小实蝇卵的寄生效能

在温度25℃、相对湿度75%、光周期L∶D=12∶12的条件下,研究了阿里山潜蝇茧蜂对橘小实蝇卵的寄生效能。结果表明:橘小实蝇卵的密度变化对阿里山潜蝇茧蜂的寄生作用有很大影响,可用功能反应模型HollingⅡ型模拟,其模拟方程为Na=0.9082N0/(1 0.0046N0);阿里山潜蝇茧蜂成虫的自身密度对寄生作用也有较大影响,可用Hassell-Varley模型模拟,其模拟方程为α=0.2858P-0.3448。     

黄色潜蝇茧蜂寄生功能反应的研究

实验结果表明,南美斑潜蝇幼虫的密度,对黄色潜蝇茧蜂的寄生作用有一定程度的影响,随寄主幼虫密度的增加,被寄生的幼虫数量相对变少。黄色潜蝇茧蜂对南美斑潜蝇幼虫的瞬时攻击率为0．3886,寄生一头寄主幼虫需要0．624小时,在24小时内寄生量的最大理论值为38．46头。黄色潜蝇茧蜂成虫自身密度,对寄生作用也有一定程度的影响,随着黄色潜蝇茧蜂数量的逐渐增加,寄生蜂的发现域逐渐变小,说明寄生蜂之间存在相互干扰作用。     

橘小实蝇寄生蜂切割潜蝇茧蜂的人工繁殖技术

切割潜蝇茧蜂[Psyttalia incisi(S ilvestri)]是福建疫区寄生于橘小实蝇[Bactrocera dorsalis(Hendel)]幼虫—蛹期的重要本地寄生蜂。利用室内大量繁殖的橘小实蝇幼虫作为寄主,在室内条件下对其进行人工繁殖技术研究,并设计了人工繁蜂的质量控制和工艺流程。旨在将来提供足够数量的寄生蜂来满足田间放蜂的需要,尽早实现对橘小实蝇的持续、有效地治理。     

橘小实蝇一种重要的寄生蜂-凡氏费氏茧蜂

橘小实蝇寄生蜂凡氏费氏茧蜂Fopius vandenboschi（Fullaway）隶属膜翅目小茧蜂科潜蝇茧蜂亚科,是田间控制橘小实蝇的优势蜂种,在国外田间控制橘小实蝇已获得巨大成功,而国内应用寄生蜂田间控制橘小实蝇尚属空白。本研究室在研究中发现田间已有凡氏费氏茧蜂F.vandenbosch定殖,并室内繁殖成功。本文详细地描述了该寄生蜂的特征,旨在为田间应用奠定基础。     

应用寄生蜂和不育雄虫防控田间橘小实蝇

食品安全已成为当今社会广受关注的问题。尽管国内的一些学者就阿里山潜蝇茧蜂[Fopius arisanus(Sonan)]和橘小实蝇SIT技术分别开展了不同程度的研究,然而关于应用该蜂和不育雄虫对橘小实蝇[Bactrocera dorsalis(Hendel)]进行田间联合防治的研究还未见相关报道。为此,为探讨天敌昆虫和雄性不育技术对橘小实蝇的田间综合治理(IPM)技术,开展了阿里山潜蝇茧蜂和橘小实蝇不育雄虫的田间释放试验:首先应用性引诱剂降低田间野生雄虫数量;而后,释放橘小实蝇不育雄虫,进一步降低田间橘小实蝇种群数量;最后,释放阿里山潜蝇茧蜂对田间残余的橘小实蝇卵进行追踪寄生,以达到持续控制的目的。通过监测整个防控期田间橘小实蝇的种群数量以及果实受害率和防治效果作为评价指标评价该防治方法的综合防治效果。结果表明:应用阿里山潜蝇茧蜂、橘小实蝇不育雄虫并配合引诱剂的综合措施对橘小实蝇的种群数量有明显控制作用,田间总体防治效果可达90%左右。此外,提出完善橘小实蝇田间防控措施的建议,并提出该研究的不足以及有待进一步开展研究的方向。     

阿里山潜蝇茧蜂Fopius arisanus的发育起点温度和有效积温

对橘小实蝇卵寄生蜂阿里山潜蝇茧蜂Fopius arisanus(Sonan)的发育起点温度和有效积温进行了研究。结果表明,阿里山潜蝇茧蜂的卵、幼虫、蛹、雌成虫、雄成虫和世代的发育起点温度分别为9.7、8.8、8.5、8.7、8.7和9.3℃;有效积温分别为25.2.200.2、133.6、344.4、242.8和440.2日度。在19-31℃之间,阿里山潜蝇茧蜂的发育历期随温度的升高而缩短。     

基于CiteSpace的国内实蝇科寄生蜂研究可视化分析

为了全面客观地了解近国内实蝇科寄生蜂的研究现状和发展脉络,为从事该科昆虫研究和利用的学者与决策者提供数据参考,本文从文献计量学角度,利用可视化分析工具CiteSpace,从发文时间、数量、作者、机构、关键词的共现和聚类、研究演进等角度,分析了国内实蝇科寄生蜂在CNKI数据库中的文献情况。经CiteSpace分析发现,作者群体中陈家骅贡献量最大、中心度最高;研究机构中福建农林大学发文量最多。从关键词共现分析可知实蝇科寄生蜂研究的高频关键词为橘小实蝇、阿里山潜蝇茧蜂、寄生蜂;经关键词聚类发现实蝇科寄生蜂研究可聚类为阿里山潜蝇茧蜂、体型大小、切割潜蝇茧蜂、养殖方法、瓜实蝇5个方向。并通过关键词时间序列的可视化展示,直观地了解国内实蝇科寄生蜂研究的发展脉络。     

寄主大小对蝇蛹俑小蜂Spalangia endius(Walker)产卵选择和发育的影响

【背景】对寄生蜂与寄主之间关系的研究是寄生蜂有效利用的基础。寄生蜂雌蜂通常选择最适于子代蜂发育的寄主进行产卵。【方法】在室内26℃条件下,研究了橘小实蝇蛹体型大小对蝇蛹俑小蜂产卵和生长发育的影响。采用饥饿方法处理3龄橘小实蝇幼虫以获得体型大小(用体质量表示)差异较大的寄主蛹,供寄生蜂选择寄生。【结果】蝇蛹俑小蜂显著偏好寄生体型中等的寄主蛹,然而,随着寄主体型的增大,后代雌性比率增大,且寄主蛹个体大小与后代雌蜂体型大小存在显著的正相关;橘小实蝇蛹个体大小对蝇蛹俑小蜂后代发育历期和寿命无显著影响。【结论与意义】蝇蛹俑小蜂雌蜂能够根据寄主蛹质量来调整后代数量和性比,以使后代适应度最大化。     

螟蛉盘绒茧蜂的过寄生行为及其对子代生长发育的影响

【目的】过寄生现象普遍存在于寄生蜂寄生过程中。本研究旨在探究螟蛉盘绒茧蜂Cotesia ruficrus的过寄生对子代发育的影响及影响过寄生行为的主要因素。【方法】室内研究了螟蛉盘绒茧蜂在其寄主稻纵卷叶螟Cnaphalocrocis medinalis3龄幼虫上过寄生行为的发生,不同产卵次数对寄主存活及子代蜂生长发育的影响,研究了不同接蜂时间和不同接蜂密度对过寄生发生的影响。【结果】螟蛉盘绒茧蜂存在过寄生行为,无论雌蜂有无产卵寄生经历,均能在被自身寄生过和同种不同个体寄生过的寄主内产卵。寄生蜂茧量随着被产卵次数的增加而增加,被产卵3~5次的寄主体内死亡的寄生蜂幼虫数随着增大。寄主在育出蜂前的死亡率随着被产卵寄生次数的增加而增加,被产卵5次时,寄主育出蜂前死亡率达50%。过寄生使螟蛉盘绒茧蜂子代蜂卵-蛹的历期延长,羽化率和雌雄性比下降,雌蜂体型随寄生次数的增加显著变小。过寄生率随着接蜂密度及接蜂时间的增加而增加。【结论】在寄主上产卵2次对螟蛉盘绒茧蜂子代发育是最适合的,产卵3次及以上为过寄生。过寄生使蜂子代发育适合度降低,不利于子代生长发育。在室内大量繁殖螟蛉盘绒茧蜂时,应减少接蜂密度和接蜂时间,从而减少过寄生的发生。     

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.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

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.