山西口岸全国首次截获危险性蚧虫并蛎蚧

【目的】并蛎蚧属盾蚧科并蛎蚧属,该虫食性杂,危害植物种类多,极易随水果、苗木、景观花卉植物等寄主传播入境。并蛎蚧分布于美国、日本和我国台湾省,在我国大陆地区尚未见该虫的发生报道。2016年5月山西口岸从来自台北的水果释迦上截获了并蛎蚧,为我国大陆首次截获。【方法】通过显微形态特征的观察和测量进行种类鉴定,并研究并蛎蚧的生物学、生态学相关资料,对其进行风险评估。【结果】并蛎蚧与近似种的主要区别:中臀叶与第二臀叶愈合中间有腺刺,有第三对臀叶,中臀叶有向内延伸的硬化区。通过风险评估认为,来自我国台湾、日本的并蛎蚧入侵我国大陆的风险较大。并蛎蚧在大陆亚热带地区的定殖和扩散风险很大。【结论】我国大陆地区的气候条件、植物种类可为并蛎蚧的定殖提供可能的适生条件,各口岸应对进境的并蛎蚧寄主植物加强检验检疫。     

苹果密蛎蚧在枇杷上的发生和防治技术研究

苹果密蛎蚧Mytilaspisconchiformioides（Borchsenius）隶属于同翅目盾蚧科,是枇杷上的主要害虫之一。枇杷树体受到苹果密蛎蚧为害后,引起落叶,甚至抽发不出新梢和枝条而枯死,严重影响树势和产量。为了控制苹果密蛎蚧在枇杷上的发生和为害,1989～1993年作者对苹果密蛎蚧的生物学特性和防治技术进行了观察和研究。1田间发生和为害在太湖洞庭山调查的结果表明,东山枇杷栽培区苹果密蛎蚧发生占62．9％,西山枇杷栽培区苹果密蛎蚧发生占57．6％。苹果密蛎蚧主要寄生于叶梢和一、二年生枝条的缝隙里,部分寄生于当年叶片上。据作者观察,…     

警惕芒果蛎蚧Lepidosaphes tapleyi(同翅目:盾蚧科)传入中国

【背景】芒果蛎蚧属于盾蚧类昆虫,食性杂,分布广,是危害热带和亚热带水果、蔬菜和园林植物的重要害虫,主要随水果、苗木和交通工具等介质进行远距离传播。该虫被列入中华人民共和国进境植物检疫性有害生物名录。惠州口岸于2014年12月从芬兰进境的货物中截获该虫,属于我国口岸首次截获。【方法】在收集整理芒果蛎蚧的生物学、地理学等信息的基础上,介绍了芒果蛎蚧的主要形态特征、地理分布、寄主植物和生物学特性,并分析了该有害生物入侵我国的风险。【结果】芒果蛎蚧雌成虫为椭圆形,长约1.2 mm,触角每侧有1根长毛,每侧前气门有3个盘状腺,形态特征与近似种Lepidosaphes camelliae和Lepidosaphes pallida非常相似。风险分析表明,我国广东、广西、海南、云南、福建、台湾以及四川等省非常适合芒果蛎蚧生存和危害。芒果蛎蚧入侵我国会给芒果等果树造成危害,给相关产业带来损失,影响从业人员收入,还影响生态环境,可能导致生态灾难。【结论与意义】芒果蛎蚧有入侵我国的可能,加强检疫是防范该虫入侵的主要手段,生物防治是治理该虫的重要措施。     

东北地区柳蛎盾蚧的初步观察

柳蛎盾蚧Lepidosaphes salicina(Borchs.)属盾蚧科Diaspididae,为害多种绿化树木和果树。我国许多文献资料都把此种误认为榆蛎盾蚧Lepidosaphes ulmi(Linnaeus),本文根据观察柳蛎盾蚧的形态特征作些补充描述,同时又与榆蛎盾蚧相比较,以区分两者间的差异。 一、形态特征 1.雌介壳 长3.2—4.3毫米,栗褐色,边缘灰白色,外常被一薄层灰色蜡粉。前端尖,向后     

中国食蚧瓢虫名录

食蚧瓢虫在蚧虫生物防治中具有很重要的作用.根据食性可分为专性食蚧瓢虫和兼性食蚧瓢虫.本文记录了我国食蚧瓢虫8亚科26属65种,其中澳洲瓢虫和孟氏隐唇瓢虫为国外引进种.     

竹链蚧属一新种记述（同翅目：蚧总科，链蚧科）

本记述采自安徽歙县箸竹Indocalamus sp.上的链蚧属Bambusasis的一新种,凸腺竹链蚧Bambusasis prolrusus,sp.nov.     

中国大球蚧属四新记录种

大球蚧属Eulecanium Cockerell 1893,此前我国记述有8种,即:格纹白球蚧Eulecaniumalbodermis Chen 1962、桤木裸蚧Eulecanium alnicola Chen 1962、刺槐球坚蚧Eulecanium circumfluumBorchs.1955、瘤大球坚蚧Eulecanium gigantea(Shinji,1935)、昆明球坚蚧Eulecanium kunmingiFerris 1950、日本球坚蚧Eulecanium kunoensis(Kuwana,1907)、桑名球坚蚧Eulecanium kuwanaiKanda 1934和黑带球坚蚧Eulecanium nigrivitta Borchs.1959。但其中桑名球坚蚧E.kuwanai,根据原     

警惕木薯绵粉蚧入侵我国

原产南美的木薯绵粉蚧Phenacoccus manihoti Matile-Ferrero是危害木薯的重要入侵害虫,在非洲和亚洲（泰国）造成严重损失,已对我国构成入侵威胁.文章介绍了木薯绵粉蚧的鉴别特征、寄主、分布、传播方式等.适生性分析显示,我国华南地区及云南中南部、贵州、湖南、江西、浙江、四川东南部、重庆、湖北、安...     

安徽泡粉蚧属一新种(同翅目:蚧总科:粉蚧科)

记述采自安徽黄山的泡粉蚧属一新种,即黄山泡粉蚧Puto huangshanensis sp.nov.,模式标本保存在北京林业大学昆虫标本室。     

中国蚁粉蚧属的初步研究（同翅目：蚧总科：粉蚧科）

记述我国蚁粉蚧属一新种：杨凌蚁粉蚧Formicococcus yanglingensis sp.nov.,建立一新组合;天麻蚁粉蚧F.gasteris(Wang,1982)comb.nov.(移自簇粉蚧属Paraputo Liang),并将F.gastrodiae Tang(1992)作为该种的异名处理。此外,还编制了蚁粉蚧属中国种类分种检索表。新种模式标本保存在南开大学生物系昆虫标本室。     

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.     

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.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.