首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
对昌吉市棉花害虫种类进行了调查.结果表明:棉花害虫(螨)有17种,其中害螨4种,为害严重的害虫(螨)有棉铃虫、棉蚜、棉叶螨等.文章阐述了昌吉市棉花主要害虫的危害及防治现状,提出了今后对棉花害虫(螨)综合治理的意见和建议.  相似文献   

2.
Baculoviruses provide alternatives to chemicals for controlling insect pests and can be applied by spraying. Baculoviruses have a limited host range, but work relatively slowly. They are dissolved in the midgut of insect larvae to release infectious virions which enter gut epithelial cells and begin to replicate. Replication in other organs causes extensive tissue damage and eventually death. This process can take 4-5 days, but in the field may last for more than a week, allowing the larvae to feed for longer and thereby damaging the host plant. Baculovirus expression vectors expressing foreign genes, such as those for insect-specific toxins, hormones or enzymes, might alleviate this problem. We have now constructed a recombinant baculovirus derived from Autographa californica nuclear polyhedrosis virus containing an insect-specific neurotoxin from the venom of the North African (Algerian) scorpion, Androctonus australis Hector. The neurotoxin acts by causing specific modifications to the Na+ conductance of neurons, producing a presynaptic excitatory effect leading to paralysis and death; it has no effect in mice. Expression of the neurotoxin by the virus causes a reduction in the time required to kill the host insect.  相似文献   

3.
虫霉目真菌包含有重要的昆虫病原真菌,在害虫生物防治中具有很高的开发利用价值,倍受关注.对广东省乐昌市人工和自然生态系统中虫霉目真菌历经3年的调查,记录了虫霉目真菌3属3种,分别为蝗噬虫霉、蝇虫霉和飞虱虫疠霉.  相似文献   

4.
5.
昆虫作为变温动物类群,极易遭受高温胁迫的影响。研究高温胁迫对植食性昆虫的影响,可为气候变暖背景下农林害虫的种群动态监测及地理适生区预测提供重要理论依据。笔者从植食性昆虫个体、种间互作关系、种群及群落3个层面,综述了高温胁迫对植食性昆虫影响的国内外进展。研究发现,高温胁迫会对植食性昆虫个体的生长发育、繁殖及生理生化带来负面效应,但昆虫自身也会进化出一系列基于形态、行为及基因表达的热胁迫响应机制。高温胁迫对寄主植物、天敌、共生微生物的影响也能够通过种间互作传递给植食性昆虫,并导致寄主植物-植食性昆虫-天敌3级营养关系发生变化。同时,高温胁迫还能通过影响昆虫个体及种间关系,间接影响昆虫的种群动态、种群多样性及其生态功能,并可能导致植食性昆虫的种群大爆发或衰退。最后,笔者认为此领域未来研究方向为:在个体层面上,应优化高温胁迫处理方式并综合考虑干旱和降水等环境因子,开展农林害虫种群的长期野外监测,应注重高温胁迫对昆虫参与生长发育繁殖功能基因的影响;在种间关系层面上,应关注高温胁迫对昆虫关联的复杂多样的食物网及互作体系的影响;此外,应结合高温胁迫对不同昆虫种类自身生理特性和行为模式的影响,阐明温度升高对昆虫群落的影响。  相似文献   

6.
苔原是冷湿型极地自然景观类型,全世界现代苔原仅分布于北半球.综述北极苔原带昆虫的物种组成:部分苔原带种类存在较明显的形态适应,北极苔原带温度和紫外线对昆虫有较大影响,较低温度和较短的生长季节是导致昆虫多样性较低和形态变化的主要原因,当温度升高时昆虫能快速扩散到北极苔原带;综述长白山苔原带昆虫种类组成,侵入种及侵入原因,直翅目蝗虫种群适应变化和天牛、食蚜蝇、蝶类访花昆虫种类及其访花习性等研究进展.  相似文献   

7.
昆虫种群流行病的相对聚集性指标与抽样式研究   总被引:3,自引:0,他引:3  
提出适用于昆虫疾病传播方式及其强度分析的相对聚集性指标,它们是发病种群聚集度与复合种群聚集度之比.相对聚集度大,则发病中心明显,疾病水平传播的效应就较强;相对聚集度小,则发病个体分布稀疏,疾病的垂直传播和环境传播效应较为突出.同时,给出了用于昆虫种群流行病田间调查的理论抽样量公式和序贯抽样公式.  相似文献   

8.
This study used the sequence of the mitochondrial Cytochrome b (Cytb) to estimate phylogenetic relationships among host Hepialidae insects of Cordyceps sinensis. Genome DNA of host insect was extracted from the dead larva head part of 18 cordyceps populations and 2 species of Hepialus, and the Cytb fragment of host insect was amplified with PCR technique. The nucleotide sequence alignments and their homologous sequences of 24 species host Hepialidae insects of Cordyceps sinensis were obtained from GenBank and were used to construct phylogenetic trees based on neighbor-joining method. The results showed that genus Bipectilus diverged earlier than genus Hepialus and Hepialiscus. Hepialus host insects of Cordyceps sinensis have multitudinous species with different morphological characteristics and geographical distributions. The interspecific genetic differentiations are obvious in Hepialus. Thus, the genus Hepialus might be considered as polyphyletic origin. Cytb sequences have abundant variations among the host insects of Cordyceps sinensis on specific and generic level. The divergence rate of Cytb sequences among the species in Hepialus ranged from 0.23% to 9.24%, except that Hepialus pratensis and Hepialus jinshaensis have the same sequence. Cytb sequence can be used for species identification of host insects of Cordyceps sinensis, but further confirmation in more host insect species is needed. To obtain the Cytb sequence of host insect by amplifying DNA extracted from the head part of dead larva in cordyceps turns out to be an effective and accurate approach, which will be useful for studies on phylogeny and genetic structure of host insects of cordyceps populations, especially for analyzing relationships between C. sinensis and its host insects.  相似文献   

9.
This study used the sequence of the mitochondrial Cytochrome b(Cytb)to estimate phylogenetic relationships among host Hepialidae insects of Cordyceps sinensis.Genome DNA of host insect was extracted from the dead larva head part of 18 cordyceps populations and 2 species of Hepialus,and the Cytb fragment of host insect was amplified with PCR technique.The nucleotide sequence alignments and their homologous sequences of 24 species host Hepialidae insects of Cordyceps sinensis were obtained from GenBank and were used to construct phylogenetic trees based on neighbor-joining method.The results showed that genus Bipectilus diverged earlier than genus Hepialus and Hepialiscus.Hepialus host insects of Cordyceps sinensis have multitudinous species with different morphological characteristics and geographical distributions.The interspecific genetic differentiations are obvious in Hepialus.Thus,the genus Hepialus might be considered as polyphyletic origin.Cytb sequences have abundant variations among the host insects of Cordyceps sinensis on spe- cific and generic level.The divergence rate of Cytb sequences among the species in Hepialus ranged from 0.23% to 9.24%,except that Hepialus pratensis and Hepialus jinshaensis have the same sequence.Cytb sequence can be used for species identification of host insects of Cordyceps sinensis,but further confirmation in more host insect species is needed.To obtain the Cytb sequence of host insect by ampli- fying DNA extracted from the head part of dead larva in cordyceps turns out to be an effective and accurate approach,which will be useful for studies on phylogeny and genetic structure of host insects of cordyceps populations,especially for analyzing relationships between C. sinensis and its host insects.  相似文献   

10.
沼生花褶伞粗毒的毒性实验研究   总被引:2,自引:0,他引:2  
用花褶伞粗毒液对美洲蜚蠊进行腹腔注射、小鼠脑室注射、蟾蜍坐骨神经腓肠肌、蛙心灌流实验,检测了该粗毒液的毒性.结果表明,花褶伞粗毒对昆虫毒性不明显,对哺乳动物有一定毒性,可能含有神经致幻毒素裸盖菇素和一些拟胆碱成分.  相似文献   

11.
药用昆虫是指虫体全部或局部或其衍生物、分泌物及病理产物可以入药的昆虫,是重要的药用资源,在我国中医药产业中占有重要地位。井冈山具有多样的自然生境和丰富的物种资源,为了进一步摸清井冈山的药用昆虫资源本底信息,通过对井冈山地区药用昆虫资源的种类、分布、药性等开展了系统调查,研究结果发现:井冈山地区共有药用昆虫101种,隶属于12目52科,其中物种多样性最丰富的5个目是鞘翅目(15科26种)、膜翅目(7科15种)、直翅目(6科13种)、鳞翅目(7科12种)和半翅目(6科11种),合计种类占全部种类的76.2%。本研究梳理了井冈山药用昆虫研究现状和存在问题,并对我国药用昆虫开发、利用提出建议。  相似文献   

12.
Ice nucleation active(INA)bacteria are the most potent heterogeneous ice nuclei in nature,which have become an important biological resource for diverse applications.Many researches have proved that INA bacteria can raise the supercooling points(SCPs)of insect pests,then reduce their cold hardiness.However,INA bacteria‘s inefficient colonization on the surface or in the guts of insects,and the high incidence of frost injury induced by their release hampered the application of INA bacteria in controlling insect pests in agricultural fields.In this study,we constructed a recombinant plasmid mob-Tn5-iceA with the ability of broad-host-range conjugal mobilization and integration of the ina gene of icaA into chromosomal DNA of many gram-negative bacteria by Tn5 transposition.In addition,Ent.cloacae strains stably carrying iceA and expressing high ice nucleation activity(INA),even in the absence of antibiotic pressure,were constructed through conjugal mobilization and Tn5 transposition.Ent,cloacae strains have benn reported to be able to efficently colonize in the guts of insects,but have weak plant epiphytic ability.Therefore,these transgenic Ent.Cloacae may be promising candidates for control of insect pests in agricultural fields.  相似文献   

13.
本文对黄毛鼠及其体外寄生虫进行专题总结,黄毛鼠在我省分布广密度高,其组成及密度沿海高于山区,平原高于丘陵,随着海拔逐渐增高,数量逐渐减少。黄毛鼠外土唾有跳蚤。革螨、恙螨和蜱、,合计近70种之多,为鼠类之冠,由于全省范围内地形,地陀孟貌、气候、海拔及鼠类组成比等条件不同,黄毛鼠体外寄生虫的种类和数量在各地有水平分布和垂直分布的不同,闽东北山区的种类多于东南沿海平原地区。  相似文献   

14.
An insect excitatory toxin gene from Buthus martensii Karseh (BmKIT) was cloned into the expression vector, pET-28a. BmKIT was expressed as inclusion bodies in Eseherichia coli BL21 (DE3) host cells. The authenticity of in vitro expressed protein was confirmed by Western blot. The inclusion body protein band in SDS-PAGE was excised and the protein, BmKIT, was extracted. Polyelonal antibodies to the purified protein were raised in rabbits. The antibody reacted specifically with the expressed BmKIT and was used to quantify its presence in transgenic cotton.  相似文献   

15.
扰动对天敌有多食性模型稳定性的影响   总被引:1,自引:0,他引:1  
本文主要讨论了扰动对天敌具有多食性模型 x_1=x_1(r_1-a_1y), x_2=x_2(r_2-a_2y), y=y(-r_3+b_1x_1+b_2x_2)稳定性的影响。利用Liapunov函数得到了昆虫种类内部的密度制约,将促使昆虫与天敌系统进一步稳定化,进而得出同一食饵水平上的竞争是不稳定化的结论。其中后一种情况与J.M,Smith的结论完全一致。  相似文献   

16.
Loss and recovery of wings in stick insects   总被引:14,自引:0,他引:14  
Whiting MF  Bradler S  Maxwell T 《Nature》2003,421(6920):264-267
The evolution of wings was the central adaptation allowing insects to escape predators, exploit scattered resources, and disperse into new niches, resulting in radiations into vast numbers of species. Despite the presumed evolutionary advantages associated with full-sized wings (macroptery), nearly all pterygote (winged) orders have many partially winged (brachypterous) or wingless (apterous) lineages, and some entire orders are secondarily wingless (for example, fleas, lice, grylloblattids and mantophasmatids), with about 5% of extant pterygote species being flightless. Thousands of independent transitions from a winged form to winglessness have occurred during the course of insect evolution; however, an evolutionary reversal from a flightless to a volant form has never been demonstrated clearly for any pterygote lineage. Such a reversal is considered highly unlikely because complex interactions between nerves, muscles, sclerites and wing foils are required to accommodate flight. Here we show that stick insects (order Phasmatodea) diversified as wingless insects and that wings were derived secondarily, perhaps on many occasions. These results suggest that wing developmental pathways are conserved in wingless phasmids, and that 're-evolution' of wings has had an unrecognized role in insect diversification.  相似文献   

17.
福建省6种榕树及其传粉小蜂共生体系的比较   总被引:2,自引:0,他引:2  
榕树(Ficus spp.)和榕小蜂共生体系是由宿主和共生者之间的生殖配合维系的.采用隐头花序解剖、对比观察的方法研究了福建省东北部6种榕树及其共生昆虫传粉体系的种间差异.结果表明:6种榕树花的性别分离成雌花、瘿花、雄花和两性花,植株的性表达有雌雄同株和雌性两性异株的区别,雌、瘿花有或无花柄(子房柄)单层或双层排列,雄花有散生、半集中和集中着生的分布方式,花序大小、花的数量、苞片数目、孔道苞片功能分区、出飞孔形成方式均有差异并与榕小蜂的行为相对应,每种榕树通常仅有1种传粉昆虫,6种榕树及其共生小蜂分别形成各自独立的传粉体系.显然,这种传粉体系存在丰富的种间差异性,各共生体系对传粉生物学的性状有不同的进化选择,体现了共生双方进化适合度和共生对策,维护了共生体系的稳定性和独立性.  相似文献   

18.
大麦散装粮堆仓库昆虫群落组成及结构分析   总被引:4,自引:0,他引:4  
  相似文献   

19.
嗅觉在昆虫生命活动中起着重要的作用,气味结合蛋白(Odorant Binding Proteins,OBPs)和化学感受蛋白(Chemosensory Proteins,CSPs)在昆虫的嗅觉系统中发挥重要作用。近年来随着基因组学和转录组学的快速发展,蝗虫OBPCSP基因陆续被鉴定出来,部分OBP基因的功能也逐步被证实。本文针对蝗虫OBPs和CSPs的种类、结构特征、表达分布、三维结构以及生理功能等方面进行概述,为更多昆虫OBP基因的鉴定及其功能研究提供参考,也为进一步揭示昆虫-环境间的化学通讯机理以及开辟新的害虫防治策略奠定基础。  相似文献   

20.
通过对河北省小五台山鳞翅目昆虫的调查统计,整理出39科516属871种.其中优势科有夜蛾科Noctuidae,尺蛾科Geometridae,草螟科Crambidae,卷蛾科Tortricidae等;在世界动物地理区划中,小五台山鳞翅目昆虫为典型的古北界分布型,古北界成分共计223种,占总数的26.17%;古北界和东洋界共有成分共计544种,占总数的63.85%,其他区系成分所占比例仅为9.96%,说明其与东洋界的联系紧密,两界鳞翅目昆虫相互渗透,而与其他几界关系远.在中国动物地理区划中,小五台山鳞翅目昆虫分布广泛,与东北区关系紧密,复计种数为71.24%,与西藏区关系较远.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号