豚草发生地土壤昆虫群落结构及动态

采用分层取样法、大类群分类法和数理统计方法,研究了普通豚草Ambrosia artemisiifolia和三裂叶豚草A．trifida发生地土壤昆虫的群落结构及动态。共采集土壤昆虫46个科（成虫与幼虫分开单列）,隶属于12个目,其中弹尾目个体数占绝对优势（占土壤昆虫总个体数的80.879%）,其次是膜翅目（8.765%）、鞘翅目幼虫（3.951%）和双翅目虫（3.093%）,其余合计占3.312%。在46个科中,优势类群有3科：棘跳虫科（Onychiuridae）（占土壤昆虫总个体数的32.756%）、鳞跳虫科（Tomoceridae）（18.869%）和节跳虫科（Isotomidae）（18.178%）。土壤昆虫个体数和类群数,随着豚草生长季的推进而增加,8月达到最高值。豚草降低了土壤昆虫的个体数量和群落多样性,根据逐月方差分析和多重比较,8月和9月对照样地土壤昆虫个体数量和多样性指数均显著高于豚草样地。豚草表现出对某些土壤昆虫类群的驱避作用,步甲科（Carabidae）成虫、拟花萤科（Dasytidae）幼虫、叶蝉科（Jassidae）、阎甲科（Histeridae）和管蓟马科（Phloeothripidae）在豚草整个生长季从未在豚草样地中出现。豚草对于土壤昆虫的抑制作用在豚草纯群落和植物生长旺季更为明显。土壤昆虫的垂直分布具有明显的表聚性。     

大双角蝎蛉幼虫复眼超微结构及其在全变态类幼虫侧单眼演化中的意义

【目的】长翅目(Mecoptera)是全变态类昆虫中唯一在幼虫期具有复眼而无侧单眼的类群,是研究昆虫复眼与侧单眼之间演化关系的理想材料。本研究旨在阐明长翅目幼虫复眼的结构特征,为探讨长翅目幼虫复眼与其他全变态类幼虫侧单眼之间的进化关系提供依据。【方法】本研究运用光学显微镜、扫描和透射电子显微镜技术观察了蝎蛉科(Panorpidae)大双角蝎蛉Dicerapanorpa magna(Chou)幼虫复眼的超微结构,并依据其结构特征对长翅目幼虫复眼在全变态类幼虫侧单眼演化中的意义进行了探讨。【结果】结果表明,大双角蝎蛉幼虫复眼属于并列像眼,由50多个小眼组成。小眼由1个角膜、1个晶体、8个视网膜细胞、2个初级色素细胞和数个次级色素细胞等组成。视网膜细胞分为4个远端细胞和4个近端细胞。远端视网膜细胞的视小杆向上延伸包裹着晶体的基部,使视杆末端呈漏斗状。【结论】分层的视网膜细胞和漏斗状的视杆很可能是长翅目幼虫复眼的共有祖征。这两个特征不存在于长翅目成虫复眼中,但存在于许多渐变态类昆虫中。由此推测,长翅目幼虫复眼可能与渐变态类昆虫的复眼存在同源关系。我们认为,长翅目幼虫独有的复眼很可能是全变态类昆虫的祖征,其他全变态类幼虫的侧单眼可能是由复眼演化来的。     

丹参田花期昆虫群落结构及多样性研究

为明确丹参田花期昆虫群落结构,本文采用马氏网对丹参花期的昆虫进行收集,分类鉴定后开展群落结构及多样性分析。结果表明,丹参花期共收集到昆虫5 438头,隶属于膜翅目Hymenoptera、双翅目Diptera、半翅目Hemiptera、鳞翅目Lepidoptera、鞘翅目Coleoptera、直翅目Orthoptera、脉翅目Neuroptera 7目52科,双翅目、膜翅目昆虫为优势类群,群落丰盛度、丰富度指数较高,Shannon-Wiener多样性指数、Pielou均匀度指数较为稳定,Simpson优势度指数较低,可见丹参田花期昆虫种群结构较为稳定。     

木瓜榕上昆虫群落结构及分布特征

对西双版纳热带雨林木瓜榕上的昆虫群落结构和分布特征进行了研究。结果表明：样地内共采集到木瓜榕树上昆虫48974号,隶属9个目,30个科,56属,70种。主要是鞘翅目、鳞翅目、膜翅目、同翅目、双翅目、等翅目、半翅目、脉翅目和缨翅目的科、属和种类。属和种以鞘翅目和膜翅目类群最丰富;个体数量是膜翅目最多, 高达68.79%, 其中56.58%是传粉类昆虫。从垂直分布规律看：种类和数量是老茎结果部位最高,占71.34%, 在青果期和熟果期表现最丰富;树冠与叶片部位次之,比率为15.68%;根部再次之(9.55%);枝杈和主干最低, 仅占3.42%。在不同季节中,雨季的种类和个体数量最高,为35.96%;干热季节次之(34.22%),干凉季节最低(29.82%)。     

中国特有植物四合木的昆虫群落与多样性特征

对中国特有植物四合木(Tetraena mongolica)植株上昆虫群落进行调查和多样性特征分析,共采得四合木上昆虫标本1935号,隶属于8目42个科(或总科)136种。包括同翅目、膜翅目、半翅目、鞘翅目、双翅目、缨翅目、直翅目和脉翅目的种类。同翅目昆虫在数量上占有绝对的优势,达67.96%。膜翅目丰富度最高,有59种;优势类群(>10%)是叶蝉,常见类群(1%～10%)包括小蜂、粒脉蜡蝉、天牛、蚂蚁、皮蝽、蚜虫和盲蝽等。调查所得昆虫群落中植食性昆虫有59种共1610只,丰富度和个体数量在群落中占有绝对的优势。其中尤以吸食类昆虫为最,其个体数量和优势度指数最大,但均匀度最低。寄生性天敌昆虫在群落中多样性最大,优势度最低,多为膜翅目种类。中性昆虫优势度指数较高。捕食性昆虫物种丰富度和个体数量较小,但多样性高,仅次于寄生性昆虫。     

中侏罗世魔蜂科一新属——Sinephialtites在中国的发现

魔蜂科(Ephialtitidae)被认为是昆虫纲膜翅目细腰亚目(Insecta,Hymenoptera,Apocrita)无腹柄的原始类群,无可置疑地属于寄生蜂类,寄主是早期的粉蠹类(Lyctidae)和树蜂类(Siricidae)的幼虫。据苏联科学院古生物研究所膜翅目学者(1975)研究认为,细腰亚目的其他类群皆是魔蜂类进化形成的,广腰亚目的卡拉达蜂科(Symphata,Karatavitidae)是魔蜂科的祖先。因此,搞清楚这个科的特征、     

棉铃虫18S核糖体RNA基因的序列分析及其分子系统学

克隆并分析了鳞翅目棉铃虫Helicoverpa armigera (Hübner)18S核糖体RNA基因(18S rDNA)的全序列,将该序列与鞘翅目、膜翅目、同翅目、双翅目、捻翅目和弹尾目各一种昆虫的同源保守区进行了比较。序列分析结果显示：鳞翅目和双翅目昆虫在18S rDNA结构上彼此较为相似,捻翅目昆虫的18S rDNA分子结构表现出与其它目昆虫有较大的差异,但相对与弹尾目昆虫的18S rDNA较为接近。该结果支持了有关捻翅目属于一个独立的目级分类阶元的论点。     

广东南岭国家级自然保护区大东山昆虫名录(Ⅴ)

本文报道广东南岭国家级自然保护区大东山管理站所辖林区鳞翅目(蝶类)11科90属168种,双翅目6科23属39种和膜翅目8科29属56种等三目昆虫名录,另蛛形纲蜘蛛目10科15种.     

膜翅目昆虫补偿性性别决定机制

膜翅目昆虫单双倍体性别决定机制(雄性是单倍体、雌性是二倍体)在昆虫纲的进化中有非常重要的作用。通常膜翅目昆虫的性别由单一位点的等位基因决定,杂合体发育成雌性,半合体发育成雄性。在近亲繁殖的情况下,一定数目的雄性会出现纯合二倍体,由于遗传阻隔这种二倍体的雄性通常是不育的。csd基因的发现为膜翅目昆虫性别决定机制提供了分子生物学证据。文章探讨CSD的分子生物学基础,对膜翅目昆虫sl-CSD的分布进行综述并且探讨膜翅目昆虫降低二倍体雄性消耗的策略以及可能存在的进化机制,最后提出几点建议以便从遗传学、生态学以及进化生物学角度全面的了解sl-CSD。     

山东省探照灯诱虫器和地面灯诱虫器诱集昆虫群落结构

[目的]山东省是昆虫南北迁飞的关键路径,了解山东省的迁飞性昆虫群落结构,对明确迁飞性昆虫种类,并对其进行预测预报具有重要意义.[方法]在山东省14个地区建立监测点,每个监测点于2018年9月-10月利用探照灯诱虫器和地面灯诱虫器诱集昆虫.[结果]14个监测点共诱捕到昆虫有12目54科408种,其中探照灯诱虫器诱集到11目45科388种,地面灯诱虫器诱集到12目46科365种,探照灯诱虫器诱集的主要昆虫类群为鳞翅目(79.12％)、鞘翅目(9.42％)、直翅目(8.14％)和脉翅目(2.26％).地面灯诱虫器诱集的主要昆虫类群为鳞翅目(68.84％)、鞘翅目(23.46％)、膜翅目(3.69％)、直翅目(1.50％)、半翅目(1.14％).探照灯诱虫器诱集昆虫数量显著多于地面灯诱虫器.[结论]阐明了山东省昆虫群落结构和多样性,并证实了许多重大昆虫在山东省存在迁飞性.     

Recent advances in insect neuropeptides

1. The number of insect neuropeptides identified chemically grows rapidly and most important neuropeptides have already been characterized. After multi-year efforts Bombyx diapause hormone has recently been isolated and sequenced.2. New approaches to search for new insect neuropeptides have been carried out by two groups of workers, which have succeeded in identifying several unique peptides.3. cDNAs for more than 10 insect neuropeptides have been cloned and sequenced. It was found that two functionally distinct neuropeptides. Bombyx diapause hormone and pheromone biosynthesis activating neuropeptide, are encoded in a single gene.     

昆虫神经肽研究进展

近年来鉴定了化学结构的昆虫神经肽数目呈快速上升趋势, 家蚕滞育激素和性信息素合成激活肽被分离纯化.三种近年出现的研究方法对寻找新型昆虫神经肽起到重要作用,已经成功地鉴定了数个新型神经肽.昆虫神经肽cDNA或基因组DNA克隆显示了新的结构信息和神经肽间的相互关系.     

Biogeography and species richness of endophagous insects associated with Proteaceae in South Africa

The endophagous insects associated with Proteaceae of the Cape fynbos were compared to endophage assemblages from more northern non-Capensis Proteaceae. Insects were collected from Proteaceae in the Cape on a regular basis and additional records obtained from insect collections. Northern samples were collected more opportunistically or records were obtained from collections or through personal communication. The Cape fynbos genus Protea is utilized by many more insect taxa than the non-fynbos Protea species. The fynbos Proteaceae has very few species in common with the northern Proteaceae, yet each has many of their own distinct species. This suggests that the fynbos endophage insect fauna is distinct from that of the other regions. It appears that the high diversity of host plants in the fynbos has contributed to generating high, local endophagous insect diversity.     

A new approach to insect-pest control—combination of neurotoxins interacting with voltage sensitive sodium channels to increase selectivity and specificity

Voltage-sensitive sodium channels are responsible for the generation of electrical signals in most excitable tissues and serve as specific targets for many neurotoxins. At least seven distinct classes of neurotoxins have been designated on the basis of physiological activity and competitive binding studies. Although the characterization of the neurotoxin receptor sites was predominantly performed using vertebrate excitable preparations, insect neuronal membranes were shown to possess similar receptor sites. We have demonstrated that the two mutually competing antiinsect excitatory and depressant scorpion toxins, previously suggested to occupy the same receptor site, bind to two distinct receptors on insect sodium channels. The latter provides a new approach to their combined use in insect control strategy. Although the sodium channel receptor sites are topologically separated, there are strong allosteric interactions among them. We have shown that the lipid-soluble sodium channel activators, veratridine and brevetoxin, reveal divergent allosteric modulation on scorpion α-toxins binding at homologous receptor sites on mammalian and insect sodium channels. The differences suggest a functionally important structural distinction between these channel subtypes. The differential allosteric modulation may provide a new approach to increase selective activity of pesticides on target organisms by simultaneous application of allosterically interacting drugs, designed on the basis of the selective toxins. Thus, a comparative study of neurotoxin receptor sites on mammalian and invertebrate sodium channels may elucidate the structural features involved in the binding and activity of the various neurotoxins, and may offer new targets and approaches to the development of highly selective pesticides.     

Symbiosis and insect diversification: an ancient symbiont of sap-feeding insects from the bacterial phylum Bacteroidetes

Several insect groups have obligate, vertically transmitted bacterial symbionts that provision hosts with nutrients that are limiting in the diet. Some of these bacteria have been shown to descend from ancient infections. Here we show that the large group of related insects including cicadas, leafhoppers, treehoppers, spittlebugs, and planthoppers host a distinct clade of bacterial symbionts. This newly described symbiont lineage belongs to the phylum Bacteroidetes. Analyses of 16S rRNA genes indicate that the symbiont phylogeny is completely congruent with the phylogeny of insect hosts as currently known. These results support the ancient acquisition of a symbiont by a shared ancestor of these insects, dating the original infection to at least 260 million years ago. As visualized in a species of spittlebug (Cercopoidea) and in a species of sharpshooter (Cicadellinae), the symbionts have extraordinarily large cells with an elongate shape, often more than 30 mum in length; in situ hybridizations verify that these correspond to the phylum Bacteroidetes. "Candidatus Sulcia muelleri" is proposed as the name of the new symbiont.     

Characterization and identification of the integrin family in silkworm, Bombyx mori

As an important economic insect, Bombyx mori is also a useful model organism for lepidopteran insect. Integrins are evolutionarily conserved from sponges to humans, and play vital roles in many physiological and pathological processes. To explore their diverse functions of integrins in insect, eleven integrins including six α and five β subunits were cloned and characterized from silkworm. Our results showed that integrins from silkworm own more family members compared to other invertebrates. Among those α subunits, integrins α1, α2, and the other four subunits belong to PS1, PS2, and PS3 groups, respectively. The β subunits mainly gather in the insect βν group except the β1 subunit which belongs to the insect β group. Expression profiles demonstrated that the integrins exhibited distinct patterns, but were mainly expressed in hemocytes. α1 and β2 subunits are the predominant ones either in the embryogenesis or larva stages. Interestingly, integrins were significantly up-regulated after stimulated by 20-hydroxyecdysone (20-E) in vivo. These results indicate that integrins perform diverse functions in hemocytes of silkworm. Overall, our results provide a new insight into the functional and evolutionary features of integrins.     

Phylogenetic analysis and classification of insect achaete-scute complex genes

Achaete-scute complex (ASC) genes play essential roles in neurogenesis of eukaryotes. Insect ASC genes are currently grouped into two distinct families, ASCa and ASCb. However, the identified insect ASCb family genes are not orthologous to known ASCb family genes from other animals such as nematode and mammal. Besides, many ASC genes have been annotated differently in GenBank. In this study, ASC genes from 41 insect species were obtained in silico and analyzed to clarify their evolutionary relationships with known ASC genes from other animals. Based on our analyses, a new naming system is suggested for classification of ASC genes. Firstly, a new family (ASCc) is added into the already existing two families and the gene of this family is named Asl (Achaete-scute-like). Secondly, Ash4, Ash5 and Ash6 are used to name insect ASC genes that are not orthologous to ac, sc, l'sc and ase genes of Drosophila melanogaster and Ash1 to Ash3 genes of Bombyx mori. This naming system can be used to correct inappropriate annotations of insect ASC genes in GenBank and to classify newly identified insect ASC genes. Additionally, a vast difference was found in ASC gene composition among various insect species, suggesting that different insect species might have originated from various ancestral lineages.     

昆虫非典型嗅觉受体Orco的功能和分子结构研究进展

嗅觉受体是参与昆虫嗅觉识别过程的一类重要蛋白。在昆虫的众多嗅觉受体中, 有一类受体明显不同于其他受体, 被称为Orco。该受体基因在不同昆虫种间高度保守, 且表达广泛。Orco在昆虫嗅觉识别过程中发挥关键作用。采用基因突变或RNAi等技术使Orco基因沉默后, 昆虫会出现严重的嗅觉缺陷, 但Orco本身不与气味配体结合, 它与传统嗅觉受体形成复合体Or-Orco, 促进传统嗅觉受体在神经元树突膜上的定位并维持其稳定性, 提高传统嗅觉受体对气味反应的效率。昆虫嗅觉受体的结构与脊椎动物的G蛋白偶联受体相似, 均有7个跨膜区, 但二者的膜拓扑结构相反, 昆虫嗅觉受体的N末端位于细胞质膜内, C末端在细胞质膜外, Orco与传统嗅觉受体通过保守的C末端区域相互作用形成一种新型的配体门控离子通道--Or-Orco复合体。阐明Orco在昆虫嗅觉识别中的功能机制, 可为开创基于昆虫嗅觉行为干扰的新的害虫防治措施提供基础。     

Symbiosis and Insect Diversification: an Ancient Symbiont of Sap-Feeding Insects from the Bacterial Phylum Bacteroidetes

Several insect groups have obligate, vertically transmitted bacterial symbionts that provision hosts with nutrients that are limiting in the diet. Some of these bacteria have been shown to descend from ancient infections. Here we show that the large group of related insects including cicadas, leafhoppers, treehoppers, spittlebugs, and planthoppers host a distinct clade of bacterial symbionts. This newly described symbiont lineage belongs to the phylum Bacteroidetes. Analyses of 16S rRNA genes indicate that the symbiont phylogeny is completely congruent with the phylogeny of insect hosts as currently known. These results support the ancient acquisition of a symbiont by a shared ancestor of these insects, dating the original infection to at least 260 million years ago. As visualized in a species of spittlebug (Cercopoidea) and in a species of sharpshooter (Cicadellinae), the symbionts have extraordinarily large cells with an elongate shape, often more than 30 μm in length; in situ hybridizations verify that these correspond to the phylum Bacteroidetes. “Candidatus Sulcia muelleri” is proposed as the name of the new symbiont.     

植物与植食性昆虫相互作用的分子机制

在长期的协同进化中,植物建立起应对昆虫取食为害的精密而又复杂的防御机制,植物转录组调控中防御应答基因的表达及防御物质的合成因不同的昆虫取食方式而异。一般来说,咀嚼式口器昆虫取食时造成大面积组织伤害,可诱导植物产生伤害反应;而刺吸式口器昆虫因其特殊的口针取食,诱导植物激活病原体相关的防御途径。不同的防御途径激活不同的识别机制和信号途径。本文从信号识别和转导上综述了不同食性的昆虫取食植物时所引发的防御反应,分析了昆虫-植物相互作用关系的分子机制。