大猿叶虫生活史的研究

大猿叶虫Colaphellus bowringi是江西山区十字花科蔬菜上的重要食叶害虫,以成虫在土中越夏和越冬。由于成虫滞育期的差异,该虫的化性显示了明显的种内变异。有些个体隔年繁殖;有些个体是一化性的,仅在春季或秋季繁殖1代;有些个体是二化性的,春季和秋季各繁殖1代;有些个体是多化性的,春季1代,秋季2～3代。因此,大猿叶虫在田间一年可发生4代。在春季,滞育成虫于2月底至4月初陆续出土繁殖;在秋季,滞育成虫于8月中旬至10月初陆续出土繁殖。春季羽化的成虫于4月底至6月上旬陆续入土越夏,秋季羽化的成虫于9月中旬至12月底陆续入土越冬。大猿叶虫一生能交配多次,大多数雌虫的产卵期超过1个月,最长达67天。平均每雌产卵量：春季世代为644粒,秋季世代为963粒,最高达1.950粒。各虫态的发育历期：在15～30℃间,卵为13.78～3.14天,幼虫为22.83～6.95天,蛹为12.10～3.18天。发育阈值温度：卵为10.7℃,幼虫为8.8℃,蛹为9.6℃。非滞育成虫的寿命约为1～2个月,滞育成虫的寿命为5～38个月。滞育成虫均入土蛰伏,在土中的蛰伏深度为9～31 cm 。     

哈尔滨地区大猿叶虫发育历期与生物学特性

在哈尔滨对白菜上的大猿叶虫Colaphellus bowringi Baly的生活史和生物学习性进行观察研究。结果表明,大猿叶虫在哈尔滨地区绝大多数个体1年发生1代,少部分个体1年发生2代。主要以成虫入土在2～27cm土层中滞育越冬。越冬成虫翌年4月下旬开始出土活动。第1代发生在5上旬至7月上旬,第2代发生于6月中旬至7月中旬。所有成虫在7月下旬以后均滞育越冬。在25℃条件下,雌虫产卵期为6～55d,平均为30.95d,单雌平均产卵量为454.9粒。在25℃各虫态的发育历期为:卵(4.46±0.33)d,幼虫(8.22±0.26)d,蛹(4.17±0.22)d。各虫态发育起点温度卵为10.80℃,幼虫为10.95℃,蛹为9.79℃;有效积温卵为64.82日.度,幼虫为117.37日.度,蛹为64.36日.度。     

条纹小斑蛾的生物学特性

条纹小斑蛾Thyrassia penangae(Moor)是乌蔹莓(Japanese cayratia)的重要害虫,在南昌1年发生4～5代,以老熟幼虫结茧越冬。由于该虫各世代总有极少部分个体进入滞育,少数进入越夏的个体1年只发生2代或3代。羽化时间多出现在上午7～10时,羽化后当日或次日下午交配,交配时间集中在下午3～6时,交配一般可持续12个h左右。成虫羽化后需取食花蜜做补充营养才能充分产卵。产配后次日即可产卵。第1代成虫常将卵数十粒聚产于幼嫩叶片的背面,以后各代主要聚产于花蕾上,平均每雌产卵量为43粒。幼虫为4龄。第1代主要取食叶芽、幼枝及嫩叶,以后各代主要取食花蕾。在自然条件下各虫态发育历期:卵为4～7d;幼虫为10～14d;非滞育的茧期(指幼虫结茧后的预蛹至成虫羽化的日期)为8～11d,越夏茧期为32～40d,越冬茧期为205～224d。成虫寿命为3～13d。     

大突肩瓢虫生物学及田间种群消长研究

大突肩瓢虫5ynonycha grandis(Thunberg)在云南开远1年发生4代,以成虫在蔗茎老叶鞘内越冬.日均温26.6～27.8℃下,卵期3～4天,幼虫期9～12天,预蛹期1天,蛹期4～5天,成虫产卵前期20～25天,1个世代历期37～46天;日均温24.5～25.5℃下,卵期5～9天,幼虫期14～21天,预蛹期1～2天,蛹期5～8天,成虫产卵前期25～30天,1个世代历期45～55天.(第4代)(越冬代)各虫态历期延长,全代历期长达250余天.成虫、幼虫均捕食甘蔗绵蚜.大突肩瓢虫田间种群动态:6月初开始在蔗田出现,8～10月种群数量明显增长,11月间形成高峰,12月开始越冬.     

中华通草蛉成虫越冬体色变化与滞育的关系

对自然条件下中华通草蛉成虫越冬体色变化与滞育关系的系统研究表明,成虫在越冬过程中都经历了一个较明显的体色变化过程,主要表现在体躯底色从绿色到土黄色及体背面滞育斑由褐色到红褐色的改变,据此将成虫体色分成5个级别,在越冬过程中约80%个体体色经历了在生殖型体色（1级）和滞育型体色（4,5级）之间的明显变化,约有20%个体体色维持在2、3级,在越冬前,成虫滞育斑出现后其卵巢不再发育或者发育受抑而逐渐停止发育,滞育斑的出现是成虫开始滞育的重要标志;越冬后,随着成虫体色由滞育型向生殖型的转变,当大多数个体体色变为3级以下时,卵巢开始发育,这些结果说明,中华通草蛉越冬成虫体色的变化是其滞育越冬的一个重要形态指标,越冬前后体色的改变,标志着成虫滞育的开始和结束。     

枯叶蛱蝶越冬雌成虫的生殖休眠特征研究

【目的】为了开展枯叶蛱蝶Kallimainachus(Doyére,1840)野生种群保育、人工繁育与利用,研究了近自然实验种群越冬雌成虫生殖休眠的性质、自然休眠期及其进展过程。【方法】根据卵母细胞的成熟度,划分繁殖季直接发育雌成虫的生殖发育进度等级;主要根据越冬早期雌成虫是否即时响应适宜条件恢复发育,判定其休眠性质为滞育或静息;通过定期检查放养在近自然条件下的越冬雌成虫的生殖发育进度,阐明其自然休眠期;通过定期将越冬成虫转至25℃、光照L︰D=15︰9和RH70%条件下保育不同天数后解剖检查其生殖细胞的发育情况,判断其滞育期和后滞育静息期。【结果】(1)繁殖季雌成虫在2日龄即开始卵黄沉积,至14日龄均已发育出成熟卵母细胞,其生殖发育被划分为4个等级,日龄与发育等级呈显著线性相关。(2)将羽化于10月上旬、放养在近自然条件下的越冬雌成虫从其11日龄开始,保育在25℃条件下12 d,其生殖发育仍无启动迹象。(3)羽化于9月8日、放养于近自然条件下的雌成虫,在其10日龄时,绝大多数处于休眠状态,少量个体继续发育;羽化于10月1日的雌成虫,从10月中旬至12月下旬,几乎所有个体均处于休眠状态;次年1月上旬,部分个体的卵母细胞发育开始启动。(4)12月上旬,所有检查的近自然实验种群雌成虫均不能在25℃条件下迅速恢复生殖发育;12月下旬,大部分个体在25℃条件下恢复发育。但仍有少量个体未显示发育恢复迹象,体现了个体间存在滞育强度的差异。【结论】枯叶蛱蝶的越冬生殖休眠为典型的滞育;近自然条件下,绝大多数雌成虫从9月中旬到1月下旬处于休眠状态,部分个体在次年1月初开始生殖发育;越冬雌成虫在12月上旬前处于滞育维持阶段,自12月下旬开始逐渐进入后滞育静息期。     

小叶女贞新害虫黄环绢须野螟生物学特性

黄环绢须野螟Palpitaannulata(Fabricius)是小叶女贞(LigustrumquihouiCarr.)上新出现的一种害虫,严重危害小叶女贞叶片,造成植株枯萎、死亡,同时也危害金叶女贞(L.vicaryi)。该虫在湖南省衡阳地区1年发生3代,以蛹在土中越冬。越冬代成虫和第1、2代成虫分别于4月下旬、5月下旬和6月下旬出现。成虫产卵于嫩梢顶端叶片上,卵期3d,幼虫期9～12d。5月上旬和6月上旬分别是第1代和第2代幼虫盛发期,危害最重。越冬代成虫羽化期喷药是防治该虫的关键,在成虫期和幼虫期分别用40%氧化乐果乳油、50%辛硫磷乳油1000～1200倍或25%溴氰菊酯乳油2500～3000倍稀释液喷洒寄主叶面,可控制该虫危害。     

越冬代棉大卷叶螟的种群动态

对棉大卷叶螟Sylepta derogata Fabricius第5代、第6代室内种群饲养结果显示,该虫的有效越冬虫源为第5代滞育的老熟幼虫,滞育率24.4%～33.1%,第6代棉大卷叶螟的发生对第2年的种群基数影响不大。滞育老熟幼虫的越冬存活率为60.0%～71.9%。次年越冬代羽化的成虫雌虫少,雄虫多,单雌产卵量平均为163.4～198.8粒。     

环带锦斑蛾的生物学

环带锦斑蛾在江西南昌一年1～3代,以幼虫在寄主基部落叶层的叶片内越冬。根据其种群在生活史上的分化,可分为:连续发育型,一年3代;二代滞育型,一年2代;一代滞育型,一年1代。卵聚产于寄主枝秆、叶腋和叶片上。越冬幼虫6～7龄;非滞育幼虫5龄。成虫寿命,雌虫10～15天,雄虫7～10天。讨论了该虫生活史上的~α分散适应”对策的意义。     

高粱条螟在湘北地区的发生动态

用越冬幼虫及其后代研究了高粱条螟Procerasvenosatus (Walker)的年生活史和未成熟的发育分级特征。结果表明 :卵、幼虫、蛹分级分龄选用的特征比较明显、稳定 ;高粱条螟在湘北地区为兼性滞育昆虫 ,幼虫既能以滞育方式越冬、越夏 ,也能以滞育方式越冬连越夏或者越夏连越冬 ,每年发生 1～ 2代 ;各虫态历期为 :成虫产卵前期 2～ 3d ,卵期 7～ 1 0d ;1龄幼虫期 2～ 3d,2龄 6～ 7d ,3龄 5～ 7d,4龄 9～ 1 1d ,5龄 8～ 1 0d ,6龄 1 1～ 1 2d ,蛹期 9～ 1 1d。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV