刺桐姬小蜂对不同品种刺桐属植物为害差异性研究

通过对广东境内刺桐属植物与刺桐姬小蜂分布情况的调查研究,发现广东省主要有刺桐、金脉刺桐、鸡冠刺桐、象牙花和龙牙花等5种刺桐属植物分布,广东省13个地巾级行政区有刺桐姬小蜂发生;5种主要奇主中,刺桐、金脉刺桐易感虫,而鸡冠刺桐、象牙花、龙牙花较抗虫.     

刺桐姬小蜂发生习性及其虫瘿形成分析

刺桐姬小蜂Quadrastichus erythrinaeKim是新发现的重要入侵害虫,在广东省深圳地区普遍发生且危害严重,受害植株超过10000株。寄主按受害程度依次为:杂色刺桐Erythrina variegata、金脉刺桐E.variegatevar.orientialis、鸡冠刺桐E.cristagalli和龙牙花E.corallodendron。移栽2年内的刺桐树受害严重。根据虫瘿形状,将其分为球形虫瘿、卷叶形虫瘿、肥厚叶虫瘿、分散虫瘿、粗柄形虫瘿、嫩枝肿大虫瘿、花蕾肿大虫瘿并对其形成过程进行分析。首次报道了刺桐姬小蜂为害鸡冠刺桐花蕾。刺桐姬小蜂在深圳无休眠和滞育现象,常年发生。     

我国首次发现外来有害生物刺桐姬小蜂

一种可将刺桐属植物危害致死的外来有害生物——刺桐姬小蜂,日前在广东省深圳市首次被发现。国家林业局9月6日发出紧急通知,要求疫区立即组织开展疫情扑灭、根除工作,防止疫情扩展蔓延。刺桐姬小蜂目前仅分布于毛里求斯、留尼汪、新加坡,美国夏威夷和中国台湾等局部地区,主要危害刺桐属植物,能够造成叶片、嫩枝等处出现畸形、肿大、坏死,严重时引起植物大量落叶、植株死亡。刺桐姬小蜂繁殖能力强,目前对刺桐姬小蜂尚无有效防治方法。我国首次发现外来有害生物刺桐姬小蜂     

金脉刺桐嫩枝上刺桐姬小蜂虫瘿分布规律研究

刺桐姬小蜂Quadrastichus erythrinae Kim是重要外来入侵害虫,危害刺桐属多种植物。本文调查研究了金脉刺桐嫩枝上刺桐姬小蜂虫瘿的数量分布和空间格局。结果显示,金脉刺桐嫩枝上靠近生长点（芽头）一端刺桐姬小蜂虫瘿数量较多,15 cm以内占90%以上,距离越远越少,其虫瘿数量比率（Y）和枝条长度（X）关系方程为Y= 72577e-0138X。对频次分布的分析结果显示,刺桐嫩枝上虫瘿主要以虫瘿集体形式出现。获得的虫瘿空间格局主要参数平均拥挤度M*、丛生指数I、聚块性指数M*/M等均显著大于1,表明虫瘿是聚集分布且聚集程度较强。建立的Iwao M*-M方程为M*=175+351M、Taylor幂函数法则模型为lg s2=0554+1828lg〖AKx-〗。     

刺桐姬小蜂的虫瘿

刺桐姬小蜂Quadrastichus erythrinaeKim雌虫在刺桐幼嫩的组织内产卵,随着幼虫的生长,这些部位会增生,产生形式多样的虫瘿,从而影响刺桐的正常生长,特别是枝叶不能展开,影响光合作用。由于刺桐姬小蜂发育速度快,夏季平均不到1个月完成1个世代,目前严重为害海南、广东等地的多种     

姬小蜂科中国大陆一新记录属一新记录种

刺桐姬小蜂QuadrastichuserythrinaeKim是刺桐属植物的重要致瘿昆虫,2005年7月,中国大陆深圳首次发现其严重为害杂色刺桐Erythrinavariegata等,我国已将刺桐姬小蜂确定为禁止进境的检疫性有害生物。本文报道了胯姬小蜂中国大陆新记录属Quadrastichus和刺桐姬小蜂中国大陆新记录种的分类地位、形态特征、分布及寄主,描述了刺桐姬小蜂与近缘种的区别,并探讨了该种的危害情况及加强检疫的重要性。     

基于ITS条形码序列的刺桐姬小蜂分子鉴定

【目的】刺桐姬小蜂Quadrastichus erythrinae Kim体型小,传统的形态学鉴定方法难以快速准确识别。【方法】本研究测定了刺桐姬小蜂的rDNA ITS1和ITS2序列,根据18S rDNA部分序列,利用MEGA的最大相似法(Maximum Likehood)构建系统发育树。根据刺桐姬小蜂ITS1和ITS2序列设计了特异引物,应用特异引物对单只刺桐姬小蜂进行PCR扩增,可稳定地扩增出明显的目的DNA条带。【结果】研究表明,基于ITS基因的DNA条形码技术可以用于刺桐姬小蜂的快速准确鉴定。【结论】因此,采用ITS1和ITS2区的特异性引物可对刺桐姬小蜂进行快速分子鉴定。     

防治刺桐姬小蜂的药剂筛选及防治方法研究

刺桐姬小蜂Quadrastichus erythrinae Kim是一种新入侵的有害生物,仅危害刺桐属植物Erythrina spp.,繁殖能力强,扩散速度快.为了有效控制刺桐姬小蜂的危害,本研究通过施药方法、药剂浓度试验对不用作用类型的9种农药进行筛选,结果表明,使用树干注射施药防治刺桐姬小蜂效果明显高于包杆施药和喷雾;混剂25%吡虫啉·丁硫克百威防治效果较高,10 d后防治效果可以达到95%以上,其它药剂防治效果由高到低依次为:20%丁硫克百威、30%敌敌畏·氧化乐果、8%吡虫啉·啶虫脒、31%氟虫腈·三唑磷、20%氧化乐果、5%吡虫啉、5.1%吡虫啉·阿维菌素、10%敌敌畏.     

刺桐树11种挥发物对刺桐姬小蜂的野外引诱活性研究

为探明刺桐姬小蜂Quadrastichus erythrinae Kim对寄主植物上11种挥发物（4-溴丁醚苄酯、1,2-二甲苯、3-蒈烯、乙酸叶醇酯、苯甲腈、α－法呢烯、奎诺二甲基丙烯酸酯、柏木烯醇、芳樟醇、水杨酸甲酯、法呢醇）的野外引诱活性，本试验分别通过不同挥发物引诱板及不同颜色引诱板对刺桐姬小蜂进行了野外引诱活性研究，结果表明：苯甲腈的引诱效果最好，除了和1,2-二甲苯差异不显著外，跟其他挥发物的引诱效果差异显著；对雌成虫的引诱作用与1,2-二甲苯、3-蒈烯差异不显著，与其他成分差异显著；对雄成虫的引诱作用苯甲腈和水杨酸甲酯的引诱作用最好，与其他成分均差异显著；在引诱板颜色试验中，刺桐姬小蜂成虫对带荧光的翠绿色具有较强的趋性，该颜色除了和无荧光的黄色差异不显著外，跟其他颜色差异显著。     

刺桐姬小蜂生物学特性研究

刺桐姬小蜂Quadrastichus erythrinae Kim是新近发现的重要检疫性有害生物,在新加坡、毛里求斯、留尼汪、中国台湾、美国夏威夷和中国大陆深圳对刺桐属植物造成严重危害。本文结合田间观察和室内实验对刺桐姬小蜂生物学特性进行了较为系统的研究。结果表明： 刺桐姬小蜂成虫活动与温度、光照密切相关。补充营养能显著延长雌成虫寿命,但对雄成虫寿命无影响。成虫性比随环境温度变化而变化。该虫的平均怀卵量为275.8粒,30℃时成虫的产卵量和产卵率最高,分别为203.63粒和73.83%。发育起点温度和世代有效积温分别为13.37℃和458.27日·度。温度与发育历期呈显著的负相关（r**=-0.9161）。     

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.